command.js: autocomplete by candidate window

Bite-sized tasks for the spec at
docs/superpowers/specs/2026-05-24-fsh-interactive-widgets-design.md.
Verification uses node --check for JS syntax and a final manual smoke
test in the emulator; the TSVM cannot be machine-invoked.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitignore

@@ -62,11 +62,15 @@ tsvmman.pdf
 *.ilg
 *.ind
 
+assets/disk0/tvdos/bin/tautfont.png
+
+video_encoder/*
+
+.idea/vcs.xml
+
+# in-dev stuffs
 assets/disk0/home/basic/*
 assets/disk0/movtestimg/*.jpg
 assets/disk0/*.mov
 assets/diskMediabin/*
-
-video_encoder/*
-
-assets/disk0/tvdos/bin/tautfont.png
+assets/disk0/hopper/*

2taud.sh

@@ -1,8 +1,12 @@
 #!/usr/bin/env fish
 
 for f in *.mod; python3 mod2taud.py $f assets/disk0/home/music/(basename $f .mod).taud; end
+for f in *.MOD; python3 mod2taud.py $f assets/disk0/home/music/(basename $f .MOD).taud; end
 for f in *.s3m; python3 s3m2taud.py $f assets/disk0/home/music/(basename $f .s3m).taud; end
+for f in *.S3M; python3 s3m2taud.py $f assets/disk0/home/music/(basename $f .S3M).taud; end
 for f in *.it; python3 it2taud.py $f assets/disk0/home/music/(basename $f .it).taud; end
+for f in *.IT; python3 it2taud.py $f assets/disk0/home/music/(basename $f .IT).taud; end
 for f in *.xm; python3 xm2taud.py $f assets/disk0/home/music/(basename $f .xm).taud; end
+for f in *.XM; python3 xm2taud.py $f assets/disk0/home/music/(basename $f .XM).taud; end
 for f in *.mon; python3 mon2taud.py $f assets/disk0/home/music/(basename $f .mon).taud; end
 for f in *.MON; python3 mon2taud.py $f assets/disk0/home/music/(basename $f .MON).taud; end

CLAUDE.md

@@ -116,6 +116,16 @@ Use the build scripts in `buildapp/`:
 - `My_BASIC_Programs/`: Example BASIC programs for testing
 - TVDOS filesystem uses custom format with specialised drivers
 
+### TSVM JavaScript Source Encoding
+
+**Do not normalise `\uXXXX` or `\xXX` escapes in .js / .mjs files that run inside
+TSVM.** TSVM's character set is not Unicode, and the JS string literal parser
+behaves differently for raw bytes vs. escape sequences. Both forms appear in
+existing code intentionally — leave each one as-is. When writing new content,
+prefer raw UTF-8 characters in string literals (e.g. write the character `ù`
+directly, rather than a `\uXXXX`-style escape) unless you are matching a
+pattern already established in the surrounding code.
+
 ## Videotron2K
 
 The Videotron2K is a specialised video display controller with:
@@ -155,6 +165,14 @@ Peripheral memories can be accessed using `vm.peek()` and `vm.poke()` functions,
 
 - The 'gzip' namespace in TSVM's JS programs is a misnomer: the actual 'gzip' functions (defined in CompressorDelegate.kt) call Zstd functions.
 
+## Taud Tracker Engine
+
+The Taud playback engine lives in `tsvm_core/src/net/torvald/tsvm/peripheral/AudioAdapter.kt`.
+
+### Critical Implementation Notes
+
+**Re-bind the local `inst` after any mid-tick `triggerNote`.** `applyTrackerTick` binds `var inst = instruments[voice.instrumentId]` once at the top of the per-voice loop. When the note-delay (`S$Dx`) deferred trigger fires mid-tick, `triggerNote` swaps the voice's `instrumentId` — but the rest of that tick (playback-rate recompute at the `computePlaybackRate(inst, finalPitch)` line, `advanceEnvelope`, `advancePfEnvelope`, `advanceAutoVibrato`, and the fadeout / filter-env reads of `inst.*`) keeps using the captured binding. The damage on a **never-triggered voice** (`instrumentId == 0` → stale `inst = instruments[0]`, whose `samplingRate == 0`) is that `playbackRate` is overwritten with `0.0`, freezing the sample at its start for the trigger tick — perceived as "the first delayed note on a fresh channel doesn't fire" (canonical: WHEN.taud cue 0 voice 13 pattern 0x0A row 16, inst `0x11` SD2 on a fresh play). On a warm voice the stale `inst` is a real instrument with non-zero rate, so the note sounds (at the wrong rate for one tick — a sub-perceptual glitch). Re-bind `inst = instruments[voice.instrumentId]` immediately after the note-delay fire block. Any future in-tick trigger paths (currently only S$Dx) must do the same.
+
 ## TVDOS
 
 ### TVDOS Movie Formats
@@ -418,3 +436,112 @@ The different weights for Mid and Side channels reflect the perceptual importanc
 - DC frequency underamplification (using 1.0 instead of 4.0/6.0)
 - Incorrect stereo imaging and extreme side channel distortion
 - Severe frequency response errors that manifest as "clipping-like" distortion
+
+## Virtual Consoles (vtmgr)
+
+Linux-style virtual consoles for TVDOS: up to 6 independent shell sessions,
+switched with **Alt-1..Alt-6** or the **`chvt N`** builtin, **Alt-0** to exit.
+Implemented entirely in JS — **no tsvm_core changes**.
+
+### Architecture
+
+- **Dispatcher**: `assets/disk0/tvdos/sbin/vtmgr.js`. Launched directly by the
+  `TVDOS.SYS` boot block (only when `!_TVDOS_IS_VT_PANE`); when it exits (Alt-0)
+  the boot block runs `AUTOEXEC.BAT` as the bare fallback shell. Owns the
+  physical keyboard and screen. Each VT runs in its own GraalVM context/thread
+  via the existing `parallel.spawnNewContext` / `attachProgram` / `launch` API
+  (see `VMJSR223Delegate.kt` `class Parallel`). VT 1 spawns at boot; VT 2-6 are
+  lazy-spawned on first switch and re-spawned if their shell exits.
+- **Concurrency model**: truly concurrent — switching works mid-command, not
+  just at the prompt. Background panes keep running (no `Thread.suspend`; it is
+  unusable on JDK 21). A cooperative gate inside the shimmed `con.getch` parks
+  panes blocked on input; CPU-bound background panes are allowed to run.
+- **Shared memory**: one `sys.malloc` region holds a control block (active VT,
+  switch request, debounce, spawned-bits) plus, per VT, an input ring buffer and
+  a 7682-byte text-plane buffer mirroring the GPU text-area layout
+  (cursor 2 + fore 2560 + back 2560 + char 2560).
+- **Compositor** (30 Hz): blits the active VT's text plane to the physical GPU
+  text area via `sys.memcpy`, and pushes that VT's cursor-visibility into the GPU
+  blink bit (MMIO attribute byte 6, addressed at `-1 - (131072*gpuSlot + 6)`).
+- **Boot config split (`commandrc` + `AUTOEXEC.BAT`)**: environment setup and
+  app-launch are split into two files so panes can replay one without the other.
+  `\commandrc` holds the `set` commands (PATH/INCLPATH/HELPPATH/KEYBOARD) and is
+  run by the `TVDOS.SYS` boot block in **every** context (boot and pane) — it has
+  no `.BAT` extension, so the boot block runs it line-by-line (`set` mutates the
+  shared `_TVDOS.variables`, so the effect persists). `\AUTOEXEC.BAT` is the
+  **per-console launch** script (Korean IME `tvdos/i18n/korean`, then
+  `command -fancy`); it is run once per console — by each pane's bootstrap, and
+  by the boot block as the post-vtmgr fallback. No env snapshot/replay anymore;
+  each pane gets PATH/KEYBOARD/etc. natively from `commandrc`, and Korean IME
+  (a per-context `unicode.uniprint` handler) now registers in every pane.
+- **Per-pane bootstrap**: each pane re-evals `TVDOS.SYS` (with `_TVDOS_IS_VT_PANE`
+  set — which makes the boot block run `commandrc` but skip the vtmgr/AUTOEXEC
+  launch — and a `_BIOS` stub captured live from the main context) then runs
+  `command -c \AUTOEXEC.BAT`, all in ONE direct `eval` so the launcher shares
+  scope with `_TVDOS`/`files`/`execApp`.
+
+### Output/input shimming (in the pane bootstrap)
+
+`con` and the global `print`/`println` family are plain JS, so the bootstrap
+overrides them to read/write the per-VT shared-memory buffers instead of the
+physical GPU. **`sys` and `graphics` are host objects and CANNOT be overridden
+from JS** — this is the key constraint that shapes everything below.
+
+- The shimmed `print` is a faithful JS port of the GPU's TTY interpreter
+  (`GlassTty.acceptChar` + `GraphicsAdapter` handlers): control bytes, the
+  `\x84<decimal>u` "emit char by code" escape (used by `con.prnch`), CSI cursor
+  moves / erase / SGR colours, and the `?25` cursor-visibility private sequence.
+  A swallow-only parser is NOT enough — TVDOS apps drive the screen through
+  these `print` escapes.
+- `con.move`/`con.getyx` are **1-based** (mirroring `graphics.setCursorYX`'s
+  `cx-1` and `getCursorYX`'s `cx+1`); `con.addch` does NOT advance the cursor
+  (matches `graphics.putSymbol`), while `con.prnch` DOES.
+- `command.js`'s `shell.execute` reassigns the global print family to
+  `shell.stdio.out.*`, which call `sys.print` (→ physical GPU). `shell.stdio.out`
+  was made to delegate to a `globalThis.__VT_OUT` hook when present (set by the
+  bootstrap); outside a VT the hook is absent and the path is byte-identical.
+
+### Direct-VRAM apps need a VT-aware base (the `vaddr` pattern)
+
+Apps that write the text area directly via `graphics.getGpuMemBase()` (rather
+than `con.*`/`print`) bypass the shims and paint the physical screen, invading
+whatever VT is visible. They must resolve text-area byte `m` through a
+VT-aware base:
+
+```js
+// physical: backward  (byte m at gpuBase - m)   — getDev inverts to forward-native
+// VT pane:  forward   (byte m at VT_TEXT_PLANE + m, the pane buffer the compositor blits)
+const VT = (typeof globalThis.VT_TEXT_PLANE !== 'undefined')
+const VRAM_BASE = VT ? globalThis.VT_TEXT_PLANE : (graphics.getGpuMemBase() - 253950)
+const VRAM_SGN  = VT ? 1 : -1
+function vaddr(m) { return VRAM_BASE + VRAM_SGN * m }
+```
+
+`sys.memcpy`/`sys.pokeBytes` copy forward in the resolved native memory, so this
+works for both directions. The physical branch is identical to the original
+arithmetic (no regression outside vtmgr). Applied so far in
+`assets/disk0/tvdos/bin/taut.js` and `assets/disk0/hopper/include/aa.mjs`
+(used by `bb.js`). Any future direct-VRAM app needs the same one-line `vaddr`.
+
+### Files
+
+- New: `assets/disk0/tvdos/sbin/vtmgr.js` (dispatcher + per-pane bootstrap)
+- `assets/disk0/tvdos/bin/command.js`: `chvt` builtin, `[N]` prompt prefix for
+  VT 2-6, `shell.stdio.out` → `__VT_OUT` delegation
+- `assets/disk0/tvdos/TVDOS.SYS`: boot block runs `\commandrc` (env) in every
+  context, then — only when `!_TVDOS_IS_VT_PANE` — launches `tvdos/sbin/vtmgr`
+  and, on its exit, `\AUTOEXEC.BAT` as the fallback shell
+- `assets/disk0/commandrc`: env-only `set` commands (PATH/INCLPATH/HELPPATH/KEYBOARD)
+- `assets/disk0/AUTOEXEC.BAT`: per-console launch (Korean IME + `command -fancy`)
+- `assets/disk0/tvdos/bin/taut.js`, `assets/disk0/hopper/include/aa.mjs`:
+  `vaddr` VT-aware direct-VRAM addressing
+
+### Gotcha: injectIntChk vs. embedded source
+
+`execApp`/`require` run a program's source through `injectIntChk` (TVDOS.SYS),
+which sed-rewrites the **first** `while`/`for`/`do` of each kind to call a
+per-exec `tvdosSIGTERM_<hash>()` SIGTERM check. When vtmgr embeds the pane
+bootstrap as a string literal, one of those rewrites can land inside the literal
+— and the pane context has no such symbol. vtmgr strips them from the bootstrap
+string with `raw.replace(/tvdosSIGTERM_[A-Za-z0-9_]+\(\);?/g, '')`. Any future
+code that builds executable source as a string literal must do the same.

TAUD_NOTE_EFFECTS.md

@@ -1,20 +1,78 @@
 # Taud Tracker Effect Command Reference
 
-Taud is a tracker-style music format derived from ScreamTracker 3's pattern command set, extended to 16-bit effect arguments and a 4096-tone equal-temperament pitch grid. This document defines every effect command a Taud engine must implement. Each command entry has three parts: a plain explanation for composers, compatibility notes for converting patterns from ScreamTracker 3 (ST3), ImpulseTracker (IT) or ProTracker (PT), and implementation details for engine writers.
+Taud is a tracker-style music format derived from ScreamTracker 3's pattern command set, extended to 16-bit effect arguments and a 4096-tone equal-temperament pitch grid. This document defines every effect command a Taud engine **MUST** implement. Each command entry has three parts: a plain explanation for composers, compatibility notes for converting patterns from ScreamTracker 3 (ST3), ImpulseTracker (IT), FastTracker 2 (FT2) or ProTracker (PT), and implementation details for engine writers.
+
+## Conformance language
+
+The key words **MUST**, **MUST NOT**, **REQUIRED**, **SHALL**, **SHALL NOT**, **SHOULD**, **SHOULD NOT**, **RECOMMENDED**, **NOT RECOMMENDED**, **MAY**, and **OPTIONAL** in this document are to be interpreted as described in [RFC 2119](https://www.rfc-editor.org/rfc/rfc2119) and [RFC 8174](https://www.rfc-editor.org/rfc/rfc8174) when, and only when, they appear in all capitals and bold. Lowercase uses of these words carry their ordinary English meaning and impose no normative requirement.
+
+In short:
+
+- **MUST** / **MUST NOT** / **REQUIRED** / **SHALL** / **SHALL NOT** — absolute requirements / prohibitions. A conforming implementation **SHALL** observe every such rule; an implementation that violates one is non-conforming.
+- **SHOULD** / **SHOULD NOT** / **RECOMMENDED** / **NOT RECOMMENDED** — strong guidance. An implementation **MAY** deviate in particular circumstances, but the full implications **MUST** be understood and weighed before doing so.
+- **MAY** / **OPTIONAL** — truly optional. Implementations that include the feature and implementations that omit it are equally conforming, and each **MUST** be prepared to interoperate with the other (with reduced functionality where the optional feature is the means of interoperation).
+
+The "Plain" paragraph of each effect description is non-normative tutorial text; the **Compatibility** and **Implementation** paragraphs carry the normative requirements, expressed through the keywords above.
 
 ---
 
+## 0. Tracker terminologies
+
+This manual extensively uses "tracker lingo" that may not sound intuitive to the modern DAW users. This section covers some of the tracker lingo to get the concepts better understood for those who have never used trackers.
+
+* **Pattern.** A rectangular block of rows × channels, conceptually similar to a MIDI clip in a DAW but on a strict grid: at most one note event per row per channel. Patterns have a fixed row count (typically 64), and the entire song is assembled by sequencing patterns rather than by placing clips on a continuous timeline.
+
+* **Cue list** (also called *order list* in other trackers). The song-level playlist of pattern indices that defines playback order. The same pattern can appear in many cue slots — editing the pattern updates every occurrence. There is no continuous timeline; the song's runtime is whatever the cue list yields, navigated by effects B (jump) and C (break). Some trackers use one cue slot that spans the entire channels; Taud uses per-channel cues.
+
+* **Channel / Voice.** A vertical column within every pattern, fixed in count for the whole song (closer in spirit to a mixer channel than a DAW track). Each channel plays at most one note at a time; chords need multiple channels. Channels persist their state — volume, pan, vibrato phase, filter — across pattern boundaries.
+
+* **Row.** One horizontal slot within a pattern, at most one note event per channel. A row's duration is `speed × tick_duration` — see Speed and Tempo below.
+
+* **Ticks.** A row spans several ticks dictated by a "tick rate". All note effects happen on those ticks while playing. Some effects (notably sliding effects, excluding fine slides) require more than one tick for operation, and **MUST NOT** be applied when the tick rate is set to 1.
+
+* **Speed vs. Tempo.** Two independent timing knobs. **Speed** (effect A) is the number of ticks per row; **tempo** (effect T) sets the duration of one tick, conventionally expressed as BPM. To slow the song globally without changing how often per-tick effects update, lower the tempo. To give per-tick effects more iterations per row (denser vibrato, longer slides per row), raise the speed. The default is speed 6, tempo $64 → 125 BPM → 50 Hz tick rate → 120 ms per row.
+
+* **Effect column.** Each cell can carry one effect command (opcode + 16-bit argument) that fires on its row. Unlike a DAW automation lane, effects are inline with the notes — there is no continuous curve, only discrete per-row events that compose with the engine's tick loop.
+
+* **Volume column / panning column.** Two extra mini-lanes per cell, each carrying its own 6-bit value + 2-bit selector (set / slide-up / slide-down / fine-slide). They run alongside the main effect column, so a single cell can carry both a main effect *and* a volume-column slide.
+
+* **Effect memory / recall.** Most effects remember their last non-zero argument; re-issuing the same effect with `$0000` recalls and re-applies it. This is how trackers express "continue that slide" without re-typing the rate every row. Each effect has either a private memory slot or shares one with a small cohort of related effects (see §6).
+
+* **Fine slides** are basically "relatively set something" operations. They apply delta on the first tick of the row only.
+
+* **Instruments vs. samples.** Notes don't reference a sample directly — they reference an **instrument**, which wraps a sample with envelopes (volume / pan / pitch), a default note volume, an NNA (New Note Action; see below), and a fadeout setting. The same sample can be wrapped by several instruments with different envelopes, much like a sampler patch in a DAW.
+
+* **Sample loops.** Held notes don't work the way a DAW sustain pedal does. The sample itself contains a loop region (loop_start..loop_end) that the playhead replays endlessly until the note is released or cut — "sustain" comes from the sample data, not from a held key.
+
+* **Note off, note cut, note fade.** Three distinct ways a note ends. **Note cut** (`^^^` or S$Cx) silences instantly. **Note off** (`===` or an NNA = NoteOff) releases the sustain loop and lets the volume envelope's release segment play out, then fades. **Note fade** keeps the sustain loop running but begins the fadeout decay — for soft tail-offs that still sound sustained.
+
+* **NNA — New Note Action.** What happens to a still-playing note when a fresh note arrives on the same channel. Options are Cut (drop the old voice), Continue (let it ring through), Note Off (release it), or Note Fade (begin fadeout). The displaced voice becomes a background *ghost* voice — still audible but no longer addressable from the pattern. This is the tracker's substitute for polyphony across DAW MIDI clips.
+
+* **Portamento.** Automatic pitch glide toward a target note (effect G). A row carrying both a note *and* a G does **not** re-trigger the sample; instead the note becomes the target and the already-sounding sample slides into it. Distinct from generic pitch slides (E/F), which move pitch by a fixed amount per tick with no target.
+
+* **Vibrato / tremolo / panbrello.** Per-channel LFOs applied to pitch (H, U), volume (R), and panning (Y) respectively. Each has independent speed, depth, and waveform. These are not DAW automation envelopes — they're cyclic modulators, more like a synth's LFO knob.
+
+* **Arpeggio.** A chip tune staple: rapidly cycle one channel between three pitches across consecutive ticks to fake a chord on a single voice (effect J). At the default 50 Hz tick rate the cycle is fast enough to perceive as a chord rather than three separate notes.
+
+* **Sample offset.** Start sample playback partway into the sample data rather than at byte 0 (effect O). Common uses: trigger a long sample mid-attack to skip a slow onset, or pick a different drum hit from a multi-sample bank.
+
+* **Pattern jump / break / loop.** Three flow-control tools without a direct DAW analog. **B** jumps to a cue index; **C** breaks out of the current pattern into a specific row of the *next* one in the cue list; **S$Bx** sets a per-channel loop point and repeats the bracketed range a fixed number of times. They operate on the cue list, not on a timeline. This pattern-wise flow control (including delays. see below) applies to the entire channels; there will be no divergence where one channel loops but other channels don't.
+
+* **Pattern delay / fine pattern delay.** **S$Ex** repeats the current row N additional times (notes don't re-trigger across repetitions, but tick-0 events do); **S$6x** extends the current row by N additional ticks without repeating it. Together they let composers stretch row timing locally without touching global speed or tempo.
+
+* **Volume fadeout.** A linear per-tick volume decay applied after key-off (or NNA Note-Fade). For sustained instruments whose volume envelope holds non-zero forever, the fadeout is the *only* mechanism that eventually retires the voice — without a stored fadeout, key-off lets such voices ring indefinitely.
+
 ## 1. Sound device
 
-- **Bit depth:** 8-bit unsigned throughout, including the final mixdown.
-- **Sample rate:** fixed at 32000 Hz.
-- **Output channels:** strictly stereo; the mix bus always produces a two-channel frame even for mono-source samples.
+- **Bit depth:** 8-bit unsigned throughout, including the final mixdown. Conforming implementations **MUST** deliver 8-bit unsigned samples at the output stage.
+- **Sample rate:** fixed at 32000 Hz. Conforming implementations **MUST** produce output at exactly this rate; resampling to another playback rate is the responsibility of the host environment, not of the Taud engine.
+- **Output channels:** strictly stereo; the mix bus **MUST** always produce a two-channel frame, even for mono-source samples.
 
-Internal accumulators may widen to 16 or 32 bits during mixing and effect computation, but stored samples and final output are 8-bit.
+Internal accumulators **MAY** widen to 16 or 32 bits during mixing and effect computation, but stored samples and final output **MUST** be 8-bit.
 
 ## 2. Pitch system — 4096-TET
 
-One octave spans **4096 pitch units** ($1000 exactly). A 12-TET semitone therefore equals **4096 ÷ 12 ≈ 341.333 units** (≈ $0155.55), which is not an integer; this irrationality is a deliberate consequence of choosing a microtonal native grid. Implementations store channel pitch as a signed integer in Taud units, and convert to playback rate using
+One octave spans **4096 pitch units** ($1000 exactly). A 12-TET semitone therefore equals **4096 ÷ 12 ≈ 341.333 units** (≈ $0155.55), which is not an integer; this irrationality is a deliberate consequence of choosing a microtonal native grid. Implementations **MUST** store channel pitch as a signed integer in Taud units, and **MUST** convert to playback rate using
 
 ```
 playback_rate = reference_rate × 2 ^ (pitch_units / 4096)
@@ -37,13 +95,22 @@ Commonly used intervals in Taud units are listed below; all are rounded to the n
 
 ## 3. Volume system
 
-Per-note and per-channel volume runs from **$00 (silent) to $3F (full)**, a 6-bit range narrower than ST3's 0..$40. Global volume (effect V) runs 0..$FF; this wider range lets the mix bus scale the summed channel output without disturbing individual note volumes. The per-frame mix chain per channel is
+Per-note and per-channel volume runs from **$00 (silent) to $3F (full)**, a 6-bit range narrower than ST3's 0..$40. Global volume (effect V) runs 0..$FF; this wider range lets the mix bus scale the summed channel output without disturbing individual note volumes. Conforming engines **MUST** implement the per-frame mix chain per channel as
 
 ```
 mix = sample × note_vol × channel_vol × global_vol >> normalisation_shift
 ```
 
-with saturation applied before the 8-bit stereo output.
+with saturation applied before the 8-bit stereo output. Internal accumulators **MAY** widen during this computation (see §1), but the saturating clip to the 8-bit range **MUST** be performed at the boundary.
+
+`note_vol` and `channel_vol` are **two independent multiplicative axes** mirroring IT's `chan->volume` and `chan->global_volume`:
+
+- **`note_vol`** is the per-note axis. It is reset on every note re-trigger to the instrument's Default Note Volume (instrument-record byte 196). It is the target of the volume column (selectors 0 / 1 / 2 / 3), the D / K / L volume slides, and the Q retrigger volume modifier. It survives across rows until the next re-trigger.
+- **`channel_vol`** is the per-channel axis. It is **not** reset by note re-triggers — once set, it persists through any number of fresh notes on that channel. It is the target of M (set) and N (slide) only.
+
+The engine carries a third per-tick value, `row_vol`, which is the mixer-facing volume for the current tick. At every row boundary `row_vol` rebases to `note_vol`; per-tick modulators (tremolo R, tremor I) write `row_vol` only, so their effect dies cleanly at row end. Per-note slides (D, K, L, vol-col) write **both** `note_vol` and `row_vol` so the per-note baseline carries forward.
+
+Because the two axes are independent, an `M $4000` (set channel volume to full) issued after a `0.$02` (vol-col SET = 2) leaves the per-note volume untouched at 2 — the channel keeps playing quietly. Conversely, an `N` slide can fade out a channel's overall level while a vol-col SET on a fresh trigger sets the per-note baseline at full.
 
 ## 4. Rows, ticks, patterns, cues
 
@@ -54,9 +121,10 @@ A pattern is a rectangular grid of rows and channels; each cell holds one note e
 | Parameter | Value |
 |---|---|
 | Speed | $06 (6 ticks/row) |
-| Tempo byte | $65 (125 BPM; see effect T for the $18 offset) |
+| Tempo byte | $64 (125 BPM; see effect T for the $19 offset) |
 | Global volume | $80 (mid-scale) |
 | Channel volume | $3F (full) |
+| Note volume | $3F (full; reseeded from instrument's Default Note Volume on every re-trigger) |
 | Pan (all channels) | $80 (centre) |
 | cue index | $0000 |
 
@@ -71,7 +139,7 @@ Most effects recall their last non-zero argument when re-issued with $0000. Unli
 
 Every other memory-carrying effect (D, I, J, K, L, N, O, P, Q, and others) has a private slot.
 
-**Effects without recall (literal zero).** A few effects do *not* recall on $0000 — the argument is taken at face value. **M** (set channel volume), **V** (set global volume), and the volume- / panning-column SET selectors all behave this way: writing `M $0000` or `V $0000` is a literal "set to silence", not a memory recall. Converters lifting from source trackers that *do* share memory (notably ST3, where the `$00` argument may cohabit with D/E/F/etc.'s shared slot) MUST eagerly resolve the recall to an explicit value before emitting, since the Taud engine takes M / V arguments verbatim.
+**Effects without recall (literal zero).** A few effects do *not* recall on $0000 — the argument **MUST** be taken at face value. **M** (set channel volume), **V** (set global volume), and the volume- / panning-column SET selectors all behave this way: writing `M $0000` or `V $0000` is a literal "set to silence", not a memory recall. Converters lifting from source trackers that *do* share memory (notably ST3, where the `$00` argument may cohabit with D/E/F/etc.'s shared slot) **MUST** eagerly resolve the recall to an explicit value before emitting, since the Taud engine takes M / V arguments verbatim.
 
 ## 7. Opcode and argument format
 
@@ -87,7 +155,7 @@ Opcodes are single base-36 digits (0-9, then A-Z); arguments are 16-bit hexadeci
 
 **Compatibility.** ST3 `Axx` maps one-to-one: Taud `A $xx00`. ST3 `A00` is a no-op; Taud `A $0000` is likewise ignored. ProTracker `Fxx` with `xx < $20` maps to Taud `A $xx00`; `Fxx` with `xx ≥ $20` maps to T instead (see T).
 
-**Implementation.** If the high byte is non-zero, write it to `ticks_per_row`; the low byte is reserved and must be zero. The change takes effect from the row on which the A command appears. There is no memory for A.
+**Implementation.** If the high byte is non-zero, the engine **MUST** write it to `ticks_per_row`; the low byte is reserved and **MUST** be zero. The change takes effect from the row on which the A command appears. There is no memory for A.
 
 ---
 
@@ -95,11 +163,11 @@ Opcodes are single base-36 digits (0-9, then A-Z); arguments are 16-bit hexadeci
 
 **Plain.** Finishes the current row, then continues playback at row 0 of the pattern at cue position $xxyy. Use this to create song-level jumps, loops, or branching structures.
 
-**Compatibility.** ST3 `Bxx` jumps to an 8-bit cue and maps to Taud `B $00xx`. The extended 16-bit range means Taud songs may have up to $10000 cue entries.
+**Compatibility.** ST3 `Bxx` jumps to an 8-bit cue and maps to Taud `B $00xx`. The extended 16-bit range means Taud songs **MAY** have up to $10000 cue entries.
 
-**Implementation.** On the last tick of the current row, set the next cue index to the argument and the next row to 0. If the argument exceeds the song length, wrap to the song's defined restart position (cue $0000 by default). Jumps are detected by a visited `(cue, row)` set so that pathological loops do not prevent song-length computation, though they do not interrupt actual playback. There is no memory for B.
+**Implementation.** On the last tick of the current row, the engine **MUST** set the next cue index to the argument and the next row to 0. If the argument exceeds the song length, the engine **MUST** wrap to the song's defined restart position (cue $0000 by default). Jumps **SHOULD** be detected by a visited `(cue, row)` set so that pathological loops do not prevent song-length computation, though they **MUST NOT** interrupt actual playback. There is no memory for B.
 
-**Simultaneous B and C on the same row.** If a B command appears in the same row as a C command (on any channel), both fire: B chooses the cue, C chooses the row within that cue. If the two commands appear on different channels, channel priority is **ascending channel index** — the lowest-numbered channel carrying either effect wins its parameter. If both appear on the same channel row (only possible if one is a volume-column equivalent), the effect column takes precedence.
+**Simultaneous B and C on the same row.** If a B command appears in the same row as a C command (on any channel), both **MUST** fire: B chooses the cue, C chooses the row within that cue. If the two commands appear on different channels, channel priority is **ascending channel index** — the lowest-numbered channel carrying either effect wins its parameter. If both appear on the same channel row (only possible if one is a volume-column equivalent), the effect column **MUST** take precedence.
 
 ---
 
@@ -107,47 +175,47 @@ Opcodes are single base-36 digits (0-9, then A-Z); arguments are 16-bit hexadeci
 
 **Plain.** Finishes the current row, then skips ahead to row $xxyy of the **next** pattern in the cue sequence.
 
-**Compatibility.** ST3 stores `Cxx` as **BCD** (so on-disk `$10` means decimal row 10); Taud stores the argument as plain binary. When converting from ST3, decode with `row = (byte >> 4) × 10 + (byte & $0F)`. Valid ST3 source bytes are those representing decimal 0..63; out-of-range BCD bytes should clamp to row 0 on import. When exporting back to ST3, encode with `byte = ((row / 10) << 4) | (row % 10)`, clamped at row 63.
+**Compatibility.** ST3 stores `Cxx` as **BCD** (so on-disk `$10` means decimal row 10); Taud stores the argument as plain binary. When converting from ST3, converters **MUST** decode with `row = (byte >> 4) × 10 + (byte & $0F)`. Valid ST3 source bytes are those representing decimal 0..63; out-of-range BCD bytes **SHOULD** clamp to row 0 on import. When exporting back to ST3, converters **MUST** encode with `byte = ((row / 10) << 4) | (row % 10)`, clamped at row 63.
 
-**Implementation.** On the last tick of the current row, advance the cue index by 1 (or honour a co-occurring B), then set the next row to the argument. If the argument exceeds the destination pattern's row count, start the destination pattern at row 0. There is no memory for C.
+**Implementation.** On the last tick of the current row, the engine **MUST** advance the cue index by 1 (or honour a co-occurring B), then set the next row to the argument. If the argument exceeds the destination pattern's row count, the engine **MUST** start the destination pattern at row 0. There is no memory for C.
 
 ---
 
 ## D $xy00 — Volume slide (multiple forms)
 
-D's 16-bit argument encodes four mutually exclusive modes using the top nibble and the following byte. All forms operate on the channel's current volume and clip to $00..$3F after each step.
+D's 16-bit argument encodes four mutually exclusive modes using the top nibble and the following byte. **All forms operate on `note_vol`** (the per-note axis described in §3, analog of IT `chan->volume`) and clip to $00..$3F after each step. The slid value persists into following rows until the next re-trigger; `channel_vol` is **not** touched by D — for the per-channel axis, use N.
 
 ### D $0y00 — Volume slide down by $y per non-first tick
 
-**Plain.** Each tick after tick 0, volume decreases by $y. A D $0400 at speed 8 reduces volume by $1C over the row.
+**Plain.** Each tick after tick 0, `note_vol` decreases by $y. A D $0400 at speed 8 reduces volume by $1C over the row.
 
 **Compatibility.** ST3 `Dx0` (volume slide down) maps to Taud `D $0x00`. The ST3 volume cap was $40; Taud's is $3F — a very high-volume sample reaching $40 in ST3 will snap to $3F in Taud.
 
-**Implementation.** On ticks > 0, subtract the low nibble of the high byte from `channel_volume`; clamp at $00. Memory is private to D and is keyed on the full original byte (so D $0000 recalls whatever form last ran).
+**Implementation.** On ticks > 0, subtract the low nibble of the high byte from `note_vol`; clamp at $00; mirror `row_vol = note_vol`. Memory is private to D and is keyed on the full original byte (so D $0000 recalls whatever form last ran).
 
 ### D $x000 — Volume slide up by $x per non-first tick
 
-**Plain.** Each tick after tick 0, volume increases by $x. Capped at $3F.
+**Plain.** Each tick after tick 0, `note_vol` increases by $x. Capped at $3F.
 
 **Compatibility.** ST3 `D0y` (volume slide up) maps to Taud `D $y000`.
 
-**Implementation.** On ticks > 0, add the high nibble of the high byte to `channel_volume`; clamp at $3F.
+**Implementation.** On ticks > 0, add the high nibble of the high byte to `note_vol`; clamp at $3F; mirror `row_vol = note_vol`.
 
 ### D $Fy00 — Fine volume slide down by $y on tick 0
 
-**Plain.** Applies a one-shot volume reduction of $y on tick 0 only. Independent of speed. A D $FF00 behaves as a fine slide up by $F (so a request for "down by F" is reinterpreted; see below).
+**Plain.** Applies a one-shot `note_vol` reduction of $y on tick 0 only. Independent of speed. A D $FF00 behaves as a fine slide up by $F (so a request for "down by F" is reinterpreted; see below).
 
 **Compatibility.** ST3 `DFy` maps directly. The $FF edge case is preserved: ST3 treats `DFF` as fine slide up by $F rather than fine slide down by $F, and Taud follows suit.
 
-**Implementation.** On tick 0 only, subtract the low nibble of the high byte from `channel_volume`. If the low nibble is $0, treat as fine-slide-up by $F. If the high byte is $FF, treat as fine-slide-up by $F.
+**Implementation.** On tick 0 only, subtract the low nibble of the high byte from `note_vol`; mirror `row_vol = note_vol`. If the low nibble is $0, treat as fine-slide-up by $F. If the high byte is $FF, treat as fine-slide-up by $F.
 
 ### D $xF00 — Fine volume slide up by $x on tick 0
 
-**Plain.** One-shot volume increase of $x on tick 0 only.
+**Plain.** One-shot `note_vol` increase of $x on tick 0 only.
 
 **Compatibility.** ST3 `DxF` maps directly. Volume cap is $3F, lower than ST3's $40.
 
-**Implementation.** On tick 0 only, add the high nibble to `channel_volume`; clamp at $3F.
+**Implementation.** On tick 0 only, add the high nibble to `note_vol`; clamp at $3F; mirror `row_vol = note_vol`.
 
 ---
 
@@ -181,9 +249,9 @@ Coarse and fine modes are distinguished by the high nibble of the argument:
 - **MONOTONE source** (Taud `ff = 2`):
   - MONOTONE `2xx` → Taud `E $00xx` **verbatim** (Hz/tick). The engine converts the stored pitch to frequency, subtracts the argument, and converts back. MONOTONE has no fine-slide form; converters never emit `E $Fxxx` for ff=2 sources.
 
-The mode flag therefore controls **two** decoder behaviours simultaneously: (a) which numeric scale the converter should have used when emitting coarse arguments, and (b) which arithmetic the engine performs on those arguments per tick. Converters MUST set bits 0-1 (`ff`) of the song-table flags byte to match the units they emit, and MUST NOT mix scales within one Taud song.
+The mode flag therefore controls **two** decoder behaviours simultaneously: (a) which numeric scale the converter ought to have used when emitting coarse arguments, and (b) which arithmetic the engine performs on those arguments per tick. Converters **MUST** set bits 0-1 (`ff`) of the song-table flags byte to match the units they emit, and **MUST NOT** mix scales within one Taud song.
 
-Because E and F share memory in Taud (narrower than ST3's broad shared memory), an ST3 song that used `E00` or `F00` to recall a D, G, or Q argument will break on import; the converter must eagerly resolve ST3 recalls into explicit Taud arguments rather than relying on memory.
+Because E and F share memory in Taud (narrower than ST3's broad shared memory), an ST3 song that used `E00` or `F00` to recall a D, G, or Q argument will break on import; the converter **MUST** eagerly resolve ST3 recalls into explicit Taud arguments rather than relying on memory.
 
 **Implementation.** Per-tick processing:
 
@@ -241,12 +309,12 @@ Glissando control (S $1x) snaps the output pitch to the nearest semitone after e
 
 **Plain.** Slides the channel's current pitch toward the note specified in the same row, at $xxxx units per tick (after tick 0), stopping when the target is reached. A row with G and a note does **not** re-trigger the sample — the note's pitch becomes the portamento target and the already-sounding sample continues at its current pitch.
 
-The unit of `$xxxx` depends on the song-table tone mode (effect `1`, bits 1-2):
+The unit of `$xxxx` depends on the song-table tone mode (effect `1`, bits 0-1):
 
-- `ff = 0` (linear) and `ff = 1` (Amiga): 4096-TET pitch units per tick. Amiga sources should be converted to linear units on G, since the original PT G slide already operated semi-linearly within a small range and the shared-memory pitfall of E/F does not apply here.
+- `ff = 0` (linear) and `ff = 1` (Amiga): 4096-TET pitch units per tick. Amiga sources **SHOULD** be converted to linear units on G, since the original PT G slide already operated semi-linearly within a small range and the shared-memory pitfall of E/F does not apply here.
 - `ff = 2` (linear-frequency): Hz/tick. The engine walks the channel's *frequency* toward the target note's frequency by `±$xxxx` Hz each non-first tick. This is MONOTONE's `3xx` behaviour verbatim (MTSRC/MT_PLAY.PAS:620-630).
 
-**Compatibility.** ST3 `Gxx` uses an 8-bit value in period-table units; convert to Taud using the same `round(× 64/3)` scale as E/F coarse (1/16 semitone per ST3 slide unit). ST3 linear mode is the expected import source; Amiga-mode G sources should be treated as linear. MONOTONE `3xx` → Taud `G $00xx` verbatim under ff=2. G has its **own** memory slot in both ST3 and Taud, so conversion is straightforward and does not suffer the shared-memory problem of E/F.
+**Compatibility.** ST3 `Gxx` uses an 8-bit value in period-table units; converters **MUST** convert to Taud using the same `round(× 64/3)` scale as E/F coarse (1/16 semitone per ST3 slide unit). Amiga-mode G sources **SHOULD** be treated as linear. MONOTONE `3xx` → Taud `G $00xx` verbatim under ff=2. G has its **own** memory slot in both ST3 and Taud, so conversion is straightforward and does not suffer the shared-memory problem of E/F.
 
 **Implementation.**
 
@@ -346,15 +414,17 @@ on row parse (I):
 
 on every tick:
     if phase == ON:
-        play at full channel volume
+        play at the unmodulated row_vol (no gating)
         tick_in_phase += 1
         if tick_in_phase >= on_time: phase = OFF; tick_in_phase = 0
     else:
-        force output volume to 0 (base volume preserved for later effects)
+        row_vol = 0          # transient gate; note_vol / channel_vol are preserved
         tick_in_phase += 1
         if tick_in_phase >= off_time: phase = ON; tick_in_phase = 0
 ```
 
+The OFF-phase gate writes `row_vol` only; `note_vol` and `channel_vol` are untouched, so the per-row rebase (`row_vol = note_vol` at row start) restores the audible level cleanly when tremor stops.
+
 A zero `$xx` or `$yy` input becomes 1 tick after the `+1`, never zero.
 
 ---
@@ -406,9 +476,9 @@ The `tick_within_row mod 3` counter resets every row start (so every row begins
 
 ## K $xy00 — Dual: vibrato continuation and volume slide $xy
 
-**Plain.** Continues the previously started vibrato (H or U) without retriggering it, while applying a volume slide of `$xy` per non-first tick. Fine volume slides are not available in this form. The K command is implemented sorely for tracker compatibility — new compositions should prefer an explicit `H $0000` (vibrato recall) plus a volume-column slide (`1.$xy` / `2.$xy`), which carries the same semantics with one less hidden dependency.
+**Plain.** Continues the previously started vibrato (H or U) without retriggering it, while applying a volume slide of `$xy` per non-first tick. Fine volume slides are not available in this form. The K command is implemented solely for tracker compatibility — new compositions **SHOULD** prefer an explicit `H $0000` (vibrato recall) plus a volume-column slide (`1.$xy` / `2.$xy`), which carries the same semantics with one less hidden dependency.
 
-**Compatibility.** ST3 / IT `Kxy` map directly to Taud `K $xy00`: the source's `xy` argument byte goes verbatim into the high byte of the Taud argument. ProTracker / FT2 / XM `6xy` map identically. Source-tracker memory cohorts that share K's argument with D (notably the ST3 single-slot shared memory and IT's D/K/L vol-slide cohort) MUST be resolved eagerly by the converter — emit explicit arguments rather than relying on cohort sharing, since Taud's K has its own private slot.
+**Compatibility.** ST3 / IT `Kxy` map directly to Taud `K $xy00`: the source's `xy` argument byte goes verbatim into the high byte of the Taud argument. ProTracker / FT2 / XM `6xy` map identically. Source-tracker memory cohorts that share K's argument with D (notably the ST3 single-slot shared memory and IT's D/K/L vol-slide cohort) **MUST** be resolved eagerly by the converter — converters **MUST** emit explicit arguments rather than relying on cohort sharing, since Taud's K has its own private slot.
 
 **Implementation.** On row parse:
 
@@ -432,19 +502,19 @@ on every tick (including tick 0):
     apply vibrato update with memory_HU.speed / memory_HU.depth (see §H)
 
 on tick > 0:
-    channel_volume = clamp(channel_volume + slide_per_tick, 0, $3F)
-    row_volume     = channel_volume
+    note_vol = clamp(note_vol + slide_per_tick, 0, $3F)
+    row_vol  = note_vol
 ```
 
-K has its own memory slot (private). The slide always uses the per-tick form — `K $FF00` does **not** trigger a fine slide; the argument's `$F` nibbles are interpreted as `$F`-magnitude per-tick slides (down wins), matching ST3's K and IT's K semantics.
+The slide writes the per-note axis (same as D); `channel_vol` is untouched. K has its own memory slot (private). The slide always uses the per-tick form — `K $FF00` does **not** trigger a fine slide; the argument's `$F` nibbles are interpreted as `$F`-magnitude per-tick slides (down wins), matching ST3's K and IT's K semantics.
 
 ---
 
 ## L $xy00 — Dual: tone portamento continuation and volume slide $xy
 
-**Plain.** Continues the previously started tone portamento (G) without retriggering, while applying a volume slide of `$xy` per non-first tick. Fine volume slides are not available here. Like K, L is implemented sorely for tracker compatibility — new compositions should prefer an explicit `G $0000` plus a volume-column slide.
+**Plain.** Continues the previously started tone portamento (G) without retriggering, while applying a volume slide of `$xy` per non-first tick. Fine volume slides are not available here. Like K, L is implemented solely for tracker compatibility — new compositions **SHOULD** prefer an explicit `G $0000` plus a volume-column slide.
 
-**Compatibility.** ST3 / IT `Lxy` map directly to Taud `L $xy00`. ProTracker / FT2 / XM `5xy` map identically. As with K, source cohort recalls (ST3 shared memory; IT D/K/L vol-slide cohort) MUST be resolved eagerly by the converter; Taud's L has its own private slot.
+**Compatibility.** ST3 / IT `Lxy` map directly to Taud `L $xy00`. ProTracker / FT2 / XM `5xy` map identically. As with K, source cohort recalls (ST3 shared memory; IT D/K/L vol-slide cohort) **MUST** be resolved eagerly by the converter; Taud's L has its own private slot.
 
 **Implementation.** Identical machinery to K with `G` swapped for the LFO update:
 
@@ -465,19 +535,19 @@ on row parse (L):
 
 on tick > 0:
     apply tone-portamento step using memory_G.speed (see §G)
-    channel_volume = clamp(channel_volume + slide_per_tick, 0, $3F)
-    row_volume     = channel_volume
+    note_vol = clamp(note_vol + slide_per_tick, 0, $3F)
+    row_vol  = note_vol
 ```
 
-L has its own memory slot (private), separate from K's and from D's.
+The slide writes the per-note axis (same as D); `channel_vol` is untouched. L has its own memory slot (private), separate from K's and from D's.
 
 ---
 
 ## M $xx00 — Set channel volume to $xx
 
-**Plain.** Sets the channel's persistent base volume to `$xx`, in the same 6-bit `$00..$3F` range as a note's default volume. Unlike a volume-column SET (which only writes the *row* volume on a re-triggering row), M overwrites the channel's stored base volume so the change persists across subsequent rows that don't carry an explicit vol-column SET.
+**Plain.** Sets the per-channel volume axis (`channel_vol`, see §3) to `$xx`, in the same 6-bit `$00..$3F` range as a note's default volume. M is the analog of IT's `Mxx`, which writes `chan->global_volume` — it does **not** disturb the per-note volume (`note_vol`) set by the volume column or seeded from the instrument default. A vol-col SET of $02 on a note row followed by an `M $4000` on the next row therefore plays the channel at `2/63 × $3F/63 ≈ 3%` of full, *not* at full — exactly as IT would.
 
-**Compatibility.** IT `Mxx` maps directly: the source byte is taken **verbatim** with a clamp to `$3F` (IT's $40 cap snaps down by one). ST3 has no native M; OpenMPT/Schism's S3M-with-IT-extensions does, and the same verbatim-with-clamp rule applies on import. M has **no memory** — `M $0000` is a literal "set channel volume to silence", not a recall. Source-tracker shared-memory recalls (e.g., ST3's single-slot shared memory) MUST be eagerly resolved by the converter before emit.
+**Compatibility.** IT `Mxx` maps directly: the source byte **MUST** be taken **verbatim** with a clamp to `$3F` (IT's $40 cap snaps down by one). ST3 has no native M; OpenMPT/Schism's S3M-with-IT-extensions does, and the same verbatim-with-clamp rule applies on import. M has **no memory** — `M $0000` is a literal "set channel volume to silence", not a recall. Source-tracker shared-memory recalls (e.g., ST3's single-slot shared memory) **MUST** be eagerly resolved by the converter before emit.
 
 **Implementation.**
 
@@ -485,17 +555,19 @@ L has its own memory slot (private), separate from K's and from D's.
 on row parse (M):
     new_vol = (arg >> 8) & 0xFF
     if new_vol > 0x3F: new_vol = 0x3F
-    channel_volume = new_vol
-    row_volume     = new_vol
+    channel_vol = new_vol
+    # note_vol and row_vol are NOT touched. The mixer multiplies channel_vol
+    # into the per-voice gain via the volume-ramp target, so the change is
+    # heard from this tick onwards without nuking the per-note volume.
 ```
 
-The change takes effect on tick 0 of the row. There is no slide form; for that, use N. The low byte of M's argument is reserved.
+The change takes effect on tick 0 of the row (the next mixer ramp window picks it up). There is no slide form; for that, use N. The low byte of M's argument is reserved.
 
 ---
 
 ## N $xy00 — Channel volume slide
 
-**Plain.** Slides the channel's persistent base volume by `$xy` per non-first tick (or once on tick 0 for fine forms). Encoding is identical to D (see §D), but the slide acts on `channel_volume` rather than the per-row note volume — so the change persists into following rows that don't reissue N. Range and clipping match D: `$00..$3F`.
+**Plain.** Slides the per-channel volume axis (`channel_vol`, see §3 and §M) by `$xy` per non-first tick (or once on tick 0 for fine forms). Encoding is identical to D (see §D), but the slide acts on `channel_vol` — independent of `note_vol`, so vol-col SET / D-slide state on the per-note axis survives across an N. The change persists into following rows that don't reissue N. Range and clipping match D: `$00..$3F`.
 
 **Compatibility.** IT `Nxy` maps directly to Taud `N $xy00` (high byte = source argument byte, verbatim). ST3 has no native N. N's encoding sub-forms mirror D exactly:
 
@@ -506,7 +578,7 @@ The change takes effect on tick 0 of the row. There is no slide form; for that,
 
 **Memory.** N has its own private slot, separate from D's. `N $0000` recalls the last N argument and re-applies it in its original sub-form (coarse vs fine, up vs down).
 
-**Implementation.** Identical to D, with `channel_volume` substituted for the per-row volume target. After every step the result is clamped to `$00..$3F` and `row_volume` is forced to track `channel_volume` so subsequent ticks' mixing reflects the slid value:
+**Implementation.** Identical to D, with `channel_vol` substituted for `note_vol`. After every step the result is clamped to `$00..$3F`. `note_vol` and `row_vol` are **not** touched — the mixer multiplies `channel_vol` into the per-voice gain via the volume-ramp target, so the change is heard within the row without disturbing the per-note baseline:
 
 ```
 on row parse (N):
@@ -514,7 +586,7 @@ on row parse (N):
     if raw == 0: raw = memory_N
     else: memory_N = raw
     decode raw exactly as D does (FF / F0 / Fy / xF / 0y / x0 → fine-up-F / coarse / fine forms)
-    schedule per-tick (or apply once) on channel_volume; row_volume = channel_volume after each step
+    schedule per-tick (or apply once) on channel_vol — never touch note_vol / row_vol
 ```
 
 ---
@@ -576,7 +648,7 @@ The mixer reads `channel_pan` (8-bit) directly through the same path as `S $80xx
 
 ProTracker `E9x` is equivalent to Taud `Q $0x00` (retrigger only, no volume change).
 
-**Implementation.** A per-channel tick counter advances every tick, including tick 0. When it reaches `$y`, the sample retriggers (keeping current pitch), the counter resets to 0, and the volume modifier `$x` applies. The counter resets only when a row has **no** Q command; successive Q rows share and advance the counter.
+**Implementation.** A per-channel tick counter advances every tick, including tick 0. When it reaches `$y`, the sample retriggers (keeping current pitch), the counter resets to 0, and the volume modifier `$x` applies to `note_vol` (the per-note axis — IT's `chan->volume`). `channel_vol` is untouched. The counter resets only when a row has **no** Q command; successive Q rows share and advance the counter.
 
 The volume modifier table, **computed with arithmetic (no LUT)**, is:
 
@@ -591,9 +663,9 @@ The volume modifier table, **computed with arithmetic (no LUT)**, is:
 | 6 | vol × 2 / 3 | E | vol × 3 / 2 |
 | 7 | vol × 1 / 2 | F | vol × 2 |
 
-Multiplicative cases use integer arithmetic: `vol × 2 / 3` is `(vol × 2) / 3` (truncated); `vol × 3 / 2` is `(vol × 3) / 2`; `vol × 1 / 2` is `vol >> 1`; `vol × 2` is `vol << 1`. All results clip to $00..$3F after.
+Multiplicative cases **MUST** use integer arithmetic: `vol × 2 / 3` is `(vol × 2) / 3` (truncated); `vol × 3 / 2` is `(vol × 3) / 2`; `vol × 1 / 2` is `vol >> 1`; `vol × 2` is `vol << 1`. All results **MUST** clip to $00..$3F after.
 
-A note previously silenced by a cut (`^^^` or `SCx` earlier in the row) is not retriggered, matching ST3's `kST3RetrigAfterNoteCut` rule.
+A note previously silenced by a cut (`^^^` or `SCx` earlier in the row) **MUST NOT** be retriggered, matching ST3's `kST3RetrigAfterNoteCut` rule.
 
 ---
 
@@ -601,7 +673,7 @@ A note previously silenced by a cut (`^^^` or `SCx` earlier in the row) is not r
 
 **Plain.** Modulates volume with an LFO, symmetrically with H's pitch modulation. `$xx` is LFO speed, `$yy` depth; the waveform is selected by S $4x.
 
-**Compatibility.** ST3 `Rxy` uses nibbles; convert by nibble-repeat. ST3's volume cap is $40; Taud's is $3F — very deep tremolo that would have briefly clipped at $40 in ST3 may clip slightly earlier in Taud. R has its own memory slot (not shared with H/U).
+**Compatibility.** ST3 `Rxy` uses nibbles; converters **MUST** convert by nibble-repeat. ST3's volume cap is $40; Taud's is $3F — very deep tremolo that would have briefly clipped at $40 in ST3 **MAY** clip slightly earlier in Taud. R has its own memory slot (not shared with H/U).
 
 **Implementation.** Identical machinery to H with a larger shift to fit the narrower volume range:
 
@@ -613,10 +685,12 @@ on row parse (R):
 on every tick (including tick 0):
     sine = ModSinusTable[(lfo_pos >> 2) & $3F]
     vol_delta = (sine × memory_R.depth) >> 9
-    applied_vol = clamp(base_vol + vol_delta, 0, $3F)
+    row_vol = clamp(note_vol + vol_delta, 0, $3F)        # modulate around the per-note axis
     lfo_pos = (lfo_pos + memory_R.speed × 4) & $FF
 ```
 
+The LFO bias is added to `note_vol` (per-note axis, mirroring IT's tremolo on `chan->volume`) and the result lands in `row_vol`, never written back into `note_vol` itself — so the row-end rebase reseats `row_vol` cleanly and tremolo dies on the next row without leaving residue. `channel_vol` is unaffected.
+
 Peak at maximum settings: $7F × $FF >> 9 = $3F — the full volume range. Retrigger behaviour tracks the S $4x waveform nibble bit 2: cleared means retrigger on new note, set means preserve LFO position.
 
 ---
@@ -627,19 +701,19 @@ Taud splits T by which byte carries the value:
 
 ### T $xx00 (high byte non-zero) — Set tempo
 
-**Plain.** Sets the Taud tempo byte to `$xx`. The resulting BPM is `$xx + $18`: Taud byte $00 → 24 BPM, $65 → 125 BPM (default), $FF → 279 BPM.
+**Plain.** Sets the Taud tempo byte to `$xx`. The resulting BPM is `$xx + $19`: Taud byte $00 → 25 BPM, $64 → 125 BPM (default), $FF → 280 BPM.
 
-**Compatibility.** ST3 `Txx` (where `xx ∈ $20..$FF`) stores BPM directly; convert with `taud_byte = xx − $18`. Taud byte $08 corresponds to ST3's minimum BPM of 32; Taud bytes below $08 are inexpressible in ST3 and should round up to $08 (BPM 32) when exporting. OpenMPT's extended tempo slides (`T $0x` down, `T $1x` up) in S3M files map to Taud T $00xx — see below.
+**Compatibility.** ST3 `Txx` (where `xx ∈ $20..$FF`) stores BPM directly; converters **MUST** convert with `taud_byte = xx − $18`. Taud byte $07 corresponds to ST3's minimum BPM of 32; Taud bytes below $07 are inexpressible in ST3 and **SHOULD** round up to $07 (BPM 32) when exporting. OpenMPT's extended tempo slides (`T $0x` down, `T $1x` up) in S3M files map to Taud T $00xx — see below.
 
-ProTracker `Fxx` with `xx ≥ $20` maps to Taud `T $(xx − $18)00`; `Fxx` with `xx < $20` maps to A (speed) instead.
+ProTracker `Fxx` with `xx ≥ $20` maps to Taud `T $(xx − $19)00`; `Fxx` with `xx < $20` maps to A (speed) instead.
 
-**Implementation.** If the high byte is non-zero, set `tempo_byte = arg >> 8`; derive `BPM = tempo_byte + $18`; compute tick duration as `samples_per_tick = 32000 × 5 / (BPM × 2) = 80000 / BPM` (integer truncated) at the fixed 32000 Hz output rate. Example: BPM 125 → 640 samples per tick; BPM 24 → 3333 samples per tick; BPM 279 → 286 samples per tick. There is no memory for set-tempo.
+**Implementation.** If the high byte is non-zero, set `tempo_byte = arg >> 8`; derive `BPM = tempo_byte + $19`; compute tick duration as `samples_per_tick = 32000 × 5 / (BPM × 2) = 80000 / BPM` (integer truncated) at the fixed 32000 Hz output rate. Example: BPM 125 → 640 samples per tick; BPM 24 → 3200 samples per tick; BPM 280 → 286 samples per tick. There is no memory for set-tempo.
 
 ### T $00xy (high byte zero) — Tempo slide
 
 **Plain.** Adjusts the tempo continuously during the row. `$00_0y` (low nibble under a zero high nibble within the low byte) slides BPM down by `$y` per non-first tick; `$00_1y` slides up. Out-of-range encodings ($00_20 through $00_FF) are reserved and behave as no-ops.
 
-**Compatibility.** ST3 itself has only the set form; the slide forms originate in the OpenMPT/Schism extension of S3M. On export to strict ST3, slide forms are unrepresentable and should be approximated as an equivalent set-tempo on a later row.
+**Compatibility.** ST3 itself has only the set form; the slide forms originate in the OpenMPT/Schism extension of S3M. On export to strict ST3, slide forms are unrepresentable and **SHOULD** be approximated as an equivalent set-tempo on a later row.
 
 **Implementation.**
 
@@ -669,9 +743,9 @@ A tempo slide's memory slot is separate from the set-tempo path and is private t
 
 **Plain.** Sets the global mix bus volume (0..$FF). $00 is silence; $FF is full. The default is $80.
 
-**Compatibility.** ST3's global volume is 0..$40; convert with `taud_v = st3_v × 4`, clamped at $FF. On export, `st3_v = taud_v >> 2`, clamped at $40. IT's global volume is 0..$80; convert with `taud_v = it_v × 2`, clamped at $FF. On IT, the very first `V 00` command must be resolved as the song's initial global volume.
+**Compatibility.** ST3's global volume is 0..$40; converters **MUST** convert with `taud_v = st3_v × 4`, clamped at $FF. On export, `st3_v = taud_v >> 2`, clamped at $40. IT's global volume is 0..$80; converters **MUST** convert with `taud_v = it_v × 2`, clamped at $FF. On IT, the very first `V 00` command **MUST** be resolved as the song's initial global volume.
 
-**Implementation.** Write the high byte to `global_volume` on the row the command appears. The low byte is reserved. ST3's `kST3NoMutedChannels` rule applies: V on a muted channel is ignored by ST3; for strict-compatible playback Taud follows suit, but new Taud compositions should avoid muting channels that carry global effects.
+**Implementation.** The engine **MUST** write the high byte to `global_volume` on the row the command appears. The low byte is reserved. ST3's `kST3NoMutedChannels` rule applies: V on a muted channel is ignored by ST3; for strict-compatible playback Taud **MUST** follow suit, but new Taud compositions **SHOULD NOT** mute channels that carry global effects.
 
 ---
 
@@ -699,7 +773,7 @@ A tempo slide's memory slot is separate from the set-tempo path and is private t
 
 **Plain.** Modulates panning with an LFO, symmetrically with H's pitch modulation. `$xx` is LFO speed, `$yy` depth; the waveform is selected by S $5x.
 
-**Compatibility.** IT `Yxy` uses nibbles; convert by nibble-repeat. IT's panning cap is $40; Taud's is $3F — very deep vibrato that would have briefly clipped at $40 in IT may clip slightly earlier in Taud. Y has its own memory slot.
+**Compatibility.** IT `Yxy` uses nibbles; converters **MUST** convert by nibble-repeat. IT's panning cap is $40; Taud's is $3F — very deep vibrato that would have briefly clipped at $40 in IT **MAY** clip slightly earlier in Taud. Y has its own memory slot.
 
 **Implementation.** Identical machinery to H with a larger shift to fit the narrower volume range:
 
@@ -719,6 +793,87 @@ Peak at maximum settings: $7F × $FF >> 9 = $3F — the full panning range. Retr
 
 ---
 
+## 7 $xxyy — Pattern Ditto
+
+**Plain.** A per-channel "fill the rest from above" marker: the engine copies the **$xx rows immediately preceding this cell on the same channel** and pastes them $yy times starting on this row. The destination block therefore covers `$xx × $yy` rows beginning at the ditto row inclusive. Any field (note, instrument, vol-column, pan-column, effect) that the composer has explicitly written into a destination row stays put and patches the corresponding field of the copied source cell — empty fields fall through to the source. The ditto opcode itself is consumed by the marker on its arming row; the rest of that row's columns are patched from the source as usual, so an empty arming row plays back identically to the first row of the source block.
+
+For example, with `7 $1003` on row 16, rows 16..63 replay the contents of rows 0..15 three times. A `D $0400` punched onto row 22 simply overrides the effect column on that destination row; its note/vol/pan still come from the source row 6 (since (22 − 16) mod 16 = 6, and 0 + 6 = source row 6).
+
+Boundary rules:
+
+- The block stops at the end of the pattern: a ditto whose nominal span would overflow the pattern's row count clips silently at the final row.
+- `$xx = $00`, `$yy = $00`, and any `$xx` greater than the row index on which the ditto sits are all treated as no-ops — there is nothing valid to copy from.
+- A `7` cell appearing inside a source block is **not** recursively expanded: when that source row is pasted into a destination, its effect column is treated as empty. This keeps expansion single-pass and prevents unbounded nesting.
+- Flow-control effects (B, C, S$Bx, S$Ex) that fall inside a source block still fire when their copy lands on a destination row, since the engine sees them as ordinary effect cells after expansion. Composers and converters **SHOULD NOT** place S$Bx loop bounds wholly inside a ditto'd range — the loop counter is per-voice and the same destination row would be revisited twice with the same state.
+
+**Compatibility.** Unique to Taud — no ST3/IT/PT equivalent. The effect has no memory.
+
+**Implementation.** Per-voice state, all reset on pattern change alongside the existing pattern-loop / fine-pattern-delay clears:
+
+- `dittoActive: bool`
+- `dittoSourceStart: int` — first row of the source block (inclusive)
+- `dittoLength: int` — $xx, the block size
+- `dittoEndRow: int` — last destination row (inclusive)
+
+At the very top of `applyTrackerRow`, before the per-voice reset of row-scope state, build an effective cell view for each voice:
+
+```
+raw = patternRows[V.pattern][N]                            # stored cell on row N for voice V
+isArmer = (raw.effect == 0x7 and raw.effectArg != 0)
+
+if isArmer:
+    length  = (raw.effectArg >> 8) & 0xFF
+    repeats =  raw.effectArg       & 0xFF
+    if length > 0 and repeats > 0 and length <= N:
+        V.dittoSourceStart = N - length
+        V.dittoLength      = length
+        V.dittoEndRow      = min(N + length * repeats - 1, patternLength - 1)
+        V.dittoActive      = true
+    # else: malformed argument — fall through with dittoActive unchanged
+
+armRow = V.dittoSourceStart + V.dittoLength    # always equals the row that armed this ditto
+
+if V.dittoActive and armRow <= N <= V.dittoEndRow:
+    srcRow = V.dittoSourceStart + ((N - V.dittoSourceStart) mod V.dittoLength)
+    src    = patternRows[V.pattern][srcRow]
+
+    cell.note       = (raw.note != 0x0000) ? raw.note       : src.note
+    cell.instrument = (raw.instrument != 0) ? raw.instrument : src.instrument
+
+    # SEL_FINE / 0 is the canonical no-op encoding for the vol- and pan-columns;
+    # any other (selector, value) pair is a write and patches the source.
+    cell.vol, cell.volEff = (raw.volEff, raw.vol) != (SEL_FINE, 0)
+                            ? (raw.vol, raw.volEff)
+                            : (src.vol, src.volEff)
+    cell.pan, cell.panEff = (raw.panEff, raw.pan) != (SEL_FINE, 0)
+                            ? (raw.pan, raw.panEff)
+                            : (src.pan, src.panEff)
+
+    # On the armer row, the 7-opcode is consumed by the marker, so for effect-column
+    # patching purposes the destination is treated as empty. Source 7-opcodes never
+    # propagate (no recursive expansion).
+    destOp, destArg = isArmer ? (0, 0) : (raw.effect, raw.effectArg)
+    if destOp != 0:
+        cell.effect, cell.effectArg = destOp, destArg
+    elif src.effect != 0x7:
+        cell.effect, cell.effectArg = src.effect, src.effectArg
+    else:
+        cell.effect, cell.effectArg = 0, 0
+
+else:
+    cell = raw
+```
+
+The four ditto fields are not cleared at the natural end of the destination range; they simply stop matching the gating condition once `N` advances past `dittoEndRow`, and a later armer cell in the same pattern overwrites them in place. Explicit clears happen only on cue advance (B / C / natural pattern end) and full playhead reset, alongside the existing pattern-loop counters in `resetPatternLoopState` / `resetParams`.
+
+The rest of `applyTrackerRow` then dispatches on `cell` exactly as for an undittoed row — note triggering, vol/pan column application, and effect handling are unchanged. The expansion mutates the in-memory cell view only; the stored pattern data is never rewritten.
+
+Pattern-delay (S$Ex) re-runs `applyTrackerRow` on the same `N` — the ditto bookkeeping is idempotent across those re-entries because `dittoActive`, `dittoSourceStart`, `dittoLength`, and `dittoEndRow` already encode the destination range, and the armer guard `length <= N` makes repeated arming on the same row a no-op (the new state is identical to the old). The `armRow <= N` half of the gating condition is what protects against an S$Bx pattern-loop that jumps back to a row sitting strictly before the armer: rather than synthesising from a phantom source slot, the engine falls through to the raw cell.
+
+Effect dispatch sees the synthesised effect, never the literal `7` opcode of the armer cell — `OP_7` therefore exists in the engine's opcode table only as an explicit no-op for the rare malformed-armer fallthrough (`length == 0`, `repeats == 0`, or `length > N`).
+
+---
+
 ## 8 $xyzz — Bitcrusher
 
 **Plain.** Applies a bitcrusher to the current voice. The crusher has two independent stages — a sample-rate reducer (`zz`, sample-and-hold) and a bit-depth quantiser (`y`) — and shares its clipping mode (`x`) with effect 9 (Overdrive). The two stages are orthogonal: enabling either is sufficient to engage the effect, and either can be active alone.
@@ -729,7 +884,7 @@ Peak at maximum settings: $7F × $FF >> 9 = $3F — the full panning range. Retr
 - `8 $0000` disables both stages and resets the shared clipping mode to clamp.
 - `8 $x000` updates only the shared clipping mode and leaves the active depth/skip undisturbed — useful for switching between clamp/fold/wrap mid-pattern without retyping the whole argument. The same form on effect 9 has identical semantics.
 
-**Compatibility.** Unique to Taud — no ST3/IT/PT equivalent. The effect has no memory: every cell that names effect 8 must spell out its full argument (apart from the `$x000` shorthand described above). `8 $1100` ⇒ 1-bit, no skip, fold-clipped — a useful sanity check pattern.
+**Compatibility.** Unique to Taud — no ST3/IT/PT equivalent. The effect has no memory: every cell that names effect 8 **MUST** spell out its full argument (apart from the `$x000` shorthand described above). `8 $1100` ⇒ 1-bit, no skip, fold-clipped — a useful sanity check pattern.
 
 **Implementation.** Per-voice state: `bitcrusherDepth` (0..15; 0 = quantiser off), `bitcrusherSkip` (0..255), `bitcrusherCounter` (mod skip+1), `bitcrusherHeld` (last emitted sample), and `clipMode` (0..2, shared with effect 9). On row parse:
 
@@ -788,7 +943,7 @@ The voice-FX state is preserved verbatim by the NNA-ghost copier, so the post-NN
 
 ## 9 $x0zz — Overdrive
 
-**Plain.** Amplifies the voice's post-filter signal and routes it through the shared clipper. With `x = 0` (clamp) the effect is a hard-knee soft-clipping distortion; with `x = 1` (fold) it becomes a wave-folder; with `x = 2` (wrap) it produces aggressive aliased fuzz with sawtooth-style discontinuities at the rails. Volume is *not* re-normalised after clipping — `9 $00FF` clamp-clipped plays at roughly the same loudness as the dry voice once everything saturates. The middle nibble is reserved and must be zero.
+**Plain.** Amplifies the voice's post-filter signal and routes it through the shared clipper. With `x = 0` (clamp) the effect is a hard-knee soft-clipping distortion; with `x = 1` (fold) it becomes a wave-folder; with `x = 2` (wrap) it produces aggressive aliased fuzz with sawtooth-style discontinuities at the rails. Volume **MUST NOT** be re-normalised after clipping — `9 $00FF` clamp-clipped plays at roughly the same loudness as the dry voice once everything saturates. The middle nibble is reserved and **MUST** be zero.
 
 - **x — clipping mode** (shared with effect 8): `0` clamp, `1` fold, `2` wrap (see effect 8 for the precise transfer functions). Values 3..F are reserved and treated as clamp.
 - **zz — amplification index**, range $00..$FF. The applied gain is `(16 + zz) / 16`, so `$00` is 1.0× (effect inactive), `$10` is 2.0× (+6 dBFS), `$F0` is 16.0× (+24 dBFS), and `$FF` is 16.9375× (≈ +24.55 dBFS).
@@ -830,16 +985,17 @@ S is a multiplexing opcode; the **high nibble of the high byte** selects the sub
 
 # S $0x00 — Amiga LPF/LED Switch
 
-**Plain.** `$0100` turns filter off; `$0000` turns it on. The parameter of the filter is somewhat dependent on the current interpolation mode: follows Amiga 1200 LPF on 1200 mode, Amiga 500 LPF on 500 mode. For other interpolation modes, this command is no-op. (see § Effects That Modifies Global Behaviour)
+**Plain.** `$0100` turns filter off; `$0000` turns it on. The parameter of the filter is dependent on the current interpolation mode: follows Amiga 1200 LPF on 1200 mode, Amiga 500 LPF on 500 mode. For other interpolation modes, this command is no-op. (see § Effects that modifies global behaviour)
 
-**Compatibility.** ST3/IT `S00`/`S01` and PT `E00`/`E01` maps directly. To actually hear the effect, the interpolation mode must be set to one of the two Amiga modes.
+**Compatibility.** ST3/IT `S00`/`S01` and PT `E00`/`E01` map directly. To actually hear the effect, the interpolation mode **MUST** be set to one of the two Amiga modes.
 
 **Implementation.** Per-playhead boolean `ledFilterOn` (default off). Writes from row are gated on `interpolationMode ∈ {Amiga 500, Amiga 1200}`; in linear / no-interp / default modes the filter chain is bypassed entirely so the toggle is a silent no-op. The post-mix LPF chain runs on the stereo bus (left/right state per playhead) before dithering: in Amiga 500 mode a 1-pole RC LPF (R = 360 Ω, C = 0.1 µF, fc ≈ 4421 Hz) is always applied; in Amiga 1200 mode that LPF is bypassed (cutoff ~34 kHz, well above 32 kHz Nyquist — matches `pt2_paula.c`). When the LED toggle is on, an additional 2-pole Sallen-Key LPF (R1=R2=10 kΩ, C1=6800 pF, C2=3900 pF, fc ≈ 3091 Hz, Q ≈ 0.660) is run after the mode LPF. Coefficients precomputed once at SAMPLING_RATE; recurrence follows musicdsp.org #38 with `pt2_rcfilters.c` parameter mapping.
 
+---
 
 ## S $1x00 — PT/ST3/IT Glissando control
 
-**Plain.** `$1000` turns glissando off; `$1100` turns it on. When on, tone portamento (G) output is quantised to the nearest semitone ($0155 approximation) before being sent to the mixer. The internal G pitch counter still advances smoothly; only the audible pitch steps. **This command is implemented sorely for ST3/IT compatibility** and therefore only works in 12-TET context.
+**Plain.** `$1000` turns glissando off; `$1100` turns it on. When on, tone portamento (G) output **MUST** be quantised to the nearest semitone ($0155 approximation) before being sent to the mixer. The internal G pitch counter **MUST** still advance smoothly; only the audible pitch steps. **This command is implemented solely for ST3/IT compatibility** and therefore only works in 12-TET context.
 
 **Compatibility.** ST3/IT `S10`/`S11` and PT `E30`/`E31` maps directly. In Taud, "nearest semitone" uses the best integer approximation: round `pitch / $155` to the nearest integer, multiply by $155; equivalently, `snapped = (pitch + $AB) / $155 × $155`. Because $155 is an approximation of 4096/12, accumulated rounding across many octaves will drift by up to a few cents; this is documented behaviour and intentional given the microtonal grid.
 
@@ -851,7 +1007,7 @@ S is a multiplexing opcode; the **high nibble of the high byte** selects the sub
 
 **Plain.** Overrides the current note's fine-tune by applying a fixed 4096-TET offset. The index `$x` selects one of sixteen predefined pitch offsets, following ScreamTracker 3's Hz-based fine-tune table but expressed directly in Taud units. This command is implemented for ST3 compatibility.
 
-**Compatibility.** The index scheme matches ST3 exactly: `$8` is the baseline (no change), `$0..$7` are progressively flatter, `$9..$F` are progressively sharper. The Hz reference values come from the ST3 User's Manual and are reproduced here for auditability; the Taud offset is `log2(Hz / 8363) × 4096`, rounded to the nearest integer. **Format converters are advised to apply offset to the note value directly.**
+**Compatibility.** The index scheme matches ST3 exactly: `$8` is the baseline (no change), `$0..$7` are progressively flatter, `$9..$F` are progressively sharper. The Hz reference values come from the ST3 User's Manual and are reproduced here for auditability; the Taud offset is `log2(Hz / 8363) × 4096`, rounded to the nearest integer. **Format converters SHOULD apply the offset to the note value directly.**
 
 | $x | Reference Hz | Taud offset |
 |---|---|---|
@@ -996,7 +1152,7 @@ The background pool is reaped when a ghost's `fadeoutVolume` drops to zero or it
 
 **Compatibility.** ST3 `SBx` maps directly. ProTracker `E6x` maps to Taud `S $Bx00`.
 
-ST3 has a long-documented bug where pattern delay (SEx) inside a pattern-loop range causes the loop counter to decrement multiple times per visit, producing unintended behaviour. **Taud fixes this bug.** On import, ST3 songs that relied on the bug will loop fewer times in Taud. Converters that want bit-exact ST3 playback should emit a warning when SBx and SEx appear in the same channel within a loop range, or optionally flatten loops by duplicating rows.
+ST3 has a long-documented bug where pattern delay (SEx) inside a pattern-loop range causes the loop counter to decrement multiple times per visit, producing unintended behaviour. **Taud fixes this bug.** On import, ST3 songs that relied on the bug will loop fewer times in Taud. Converters that want bit-exact ST3 playback **SHOULD** emit a warning when SBx and SEx appear in the same channel within a loop range, and **MAY** flatten loops by duplicating rows.
 
 **Implementation.** State per channel: `loop_start_row` (defaulting to 0 at each pattern entry) and `loop_count` (defaulting to 0).
 
@@ -1018,7 +1174,7 @@ on row event (S $Bx00):
 on pattern change: loop_start_row = 0; loop_count = 0
 ```
 
-The crucial bug fix relative to ST3: the loop-counter decrement happens **once per actual row playback**, not once per tick-0 invocation. When SBx shares a row with SEx (pattern delay), the pattern-delay machinery replays the row as a unit, but the SBx state machine treats the whole delay group as a single visit. Implement this by gating the SBx decrement on `pattern_delay_repetition == 0`.
+The crucial bug fix relative to ST3: the loop-counter decrement **MUST** happen **once per actual row playback**, not once per tick-0 invocation. When SBx shares a row with SEx (pattern delay), the pattern-delay machinery replays the row as a unit, but the SBx state machine **MUST** treat the whole delay group as a single visit. Engines **SHOULD** implement this by gating the SBx decrement on `pattern_delay_repetition == 0`.
 
 ---
 
@@ -1028,7 +1184,7 @@ The crucial bug fix relative to ST3: the loop-counter decrement happens **once p
 
 **Compatibility.** ST3 `SCx` maps directly. ProTracker `ECx` also maps directly. ST3 ignores `SC0` (treats it as no cut at all); Taud preserves this.
 
-**Implementation.** On tick `$x`, set `output_volume = 0` but leave `base_volume` unchanged. If `$x ≥ speed`, the cut never fires. If `$x == 0`, the command is ignored. Set the `note_was_cut` flag so a later Q retrigger on the same row is suppressed.
+**Implementation.** On tick `$x`, the engine **MUST** set `output_volume = 0` but **MUST** leave `base_volume` unchanged. If `$x ≥ speed`, the cut **MUST NOT** fire. If `$x == 0`, the command **MUST** be ignored. The engine **MUST** set the `note_was_cut` flag so that a later Q retrigger on the same row is suppressed.
 
 ---
 
@@ -1036,9 +1192,9 @@ The crucial bug fix relative to ST3: the loop-counter decrement happens **once p
 
 **Plain.** Delays the triggering of the note (and any co-row instrument, offset, and volume event) until tick `$x`. Until then, any currently playing note continues.
 
-**Compatibility.** ST3 `SDx` maps directly. ProTracker `EDx` also maps directly. `SD0` plays the note normally on tick 0. If `$x ≥ speed`, the note never plays on this row and does not carry over to the next row. Some trackers allow playback of "malformed" note delays (`$x` greater than current tick speed). Taud discards those notes. If such note events have been encountered during conversion, they must be corrected on the converter.
+**Compatibility.** ST3 `SDx` maps directly. ProTracker `EDx` also maps directly. `SD0` plays the note normally on tick 0. If `$x ≥ speed`, the note **MUST NOT** play on this row and **MUST NOT** carry over to the next row. Some trackers allow playback of "malformed" note delays (`$x` greater than current tick speed); Taud **MUST** discard those notes. If such note events have been encountered during conversion, they **MUST** be corrected by the converter.
 
-**Implementation.** On row parse, defer the note-trigger event (including sample selection, volume, offset, and any volume-column effect) until tick `$x`. On tick `$x`, execute the deferred trigger. When combined with pattern delay (S $Ex00), the deferred trigger re-fires at the start of each row repetition — matching ST3's `kRowDelayWithNoteDelay` behaviour. If `$x` is greater than current tick speed, the note must be discarded (see compatibility notes above)
+**Implementation.** On row parse, the engine **MUST** defer the note-trigger event (including sample selection, volume, offset, and any volume-column effect) until tick `$x`. On tick `$x`, the engine **MUST** execute the deferred trigger. When combined with pattern delay (S $Ex00), the deferred trigger **MUST** re-fire at the start of each row repetition — matching ST3's `kRowDelayWithNoteDelay` behaviour. If `$x` is greater than the current tick speed, the note **MUST** be discarded (see compatibility notes above).
 
 ---
 
@@ -1046,7 +1202,7 @@ The crucial bug fix relative to ST3: the loop-counter decrement happens **once p
 
 **Plain.** Repeats the current row `$x` additional times (so `$x = 0` means no repeat and the row plays once; `$x = 3` means the row plays four times total). Notes do not retrigger across repetitions, but per-tick effects re-run and tick-0 events (fine slides, delayed notes) re-fire on each repetition.
 
-**Compatibility.** ST3 `SEx` maps directly. ProTracker `EEx` also maps directly. Simultaneous SEx on multiple channels: ST3 uses the first SEx in **pan order** (L1..L8 then R1..R8); **Taud uses the first SEx in ascending channel-index order** for predictability. Converters that encounter ST3 songs relying on the pan-order rule should emit a warning.
+**Compatibility.** ST3 `SEx` maps directly. ProTracker `EEx` also maps directly. Simultaneous SEx on multiple channels: ST3 uses the first SEx in **pan order** (L1..L8 then R1..R8); **Taud uses the first SEx in ascending channel-index order** for predictability. Converters that encounter ST3 songs relying on the pan-order rule **SHOULD** emit a warning.
 
 Q retrigger counters do **not** reset between SEx repetitions.
 
@@ -1054,11 +1210,11 @@ Q retrigger counters do **not** reset between SEx repetitions.
 
 ---
 
-## S $Fxxx — Funk repeat with speed $xxx (non-destructive)
+## S $Fxxx — Funk repeat (Invert loop) with speed $xxx (non-destructive)
 
 **Plain.** Produces a hiss-like progressive inversion of the sample loop, toggling individual bytes over time for a gritty textural effect. Setting `$x = 0` turns the effect off; higher `$x` advances the inversion faster.
 
-**Compatibility.** ProTracker `EFx` is destructive — it XORs bytes directly in the sample data, permanently corrupting the sample. **Taud's implementation is non-destructive**: the XOR is applied at playback time through a per-instrument bit-mask, leaving source samples pristine. ST3 does not implement SFx at all and will parse Taud's S $Fx00 as a no-op; converters targeting ST3 should drop the effect. ProTracker `EFx` imports as Taud `S $Fyyy`, where `yyy = funk_table[x]`.
+**Compatibility.** ProTracker `EFx` is destructive — it XORs bytes directly in the sample data, permanently corrupting the sample. **Taud's implementation MUST be non-destructive**: the XOR **MUST** be applied at playback time through a per-instrument bit-mask, leaving source samples pristine. ST3 does not implement SFx at all and will parse Taud's S $Fx00 as a no-op; converters targeting ST3 **SHOULD** drop the effect. ProTracker `EFx` imports as Taud `S $Fyyy`, where `yyy = funk_table[x]`.
 
 **Implementation.** Each instrument carries a `funk_mask` bit array, one bit per byte of the loop region, all zero at song start. A per-channel counter `funk_accumulator` and a per-channel `funk_write_pos` track progress.
 
@@ -1080,22 +1236,22 @@ on sample byte read during loop playback:
         output_byte = raw_byte
 ```
 
-`S $F000` clears `funk_accumulator` but leaves `funk_mask` intact (the accumulated inversion pattern persists). **On every fresh note trigger**, `funk_write_pos` resets to 0 (matching PT2's `n_wavestart = n_loopstart`); `funk_accumulator` and `funk_speed` persist across notes. The `funk_mask` itself is **only cleared on cue-start reset** (i.e. song-start / stop-and-replay) — within a single playback session it accumulates as PT2's destructive in-place edits would, but a clean replay always reproduces the same audio without needing to reload the song from disk.
+`S $F000` **MUST** clear `funk_accumulator` but **MUST** leave `funk_mask` intact (the accumulated inversion pattern persists). **On every fresh note trigger**, `funk_write_pos` **MUST** reset to 0 (matching PT2's `n_wavestart = n_loopstart`); `funk_accumulator` and `funk_speed` **MUST** persist across notes. The `funk_mask` itself **MUST** be cleared only on cue-start reset (i.e. song-start / stop-and-replay) — within a single playback session it accumulates as PT2's destructive in-place edits would, but a clean replay **MUST** reproduce the same audio without needing to reload the song from disk.
 
 ---
 
 # Volume column effects
 
-Each cell carries a 6-bit value field plus a 2-bit selector field for the volume column. The four selectors are:
+Each cell carries a 6-bit value field plus a 2-bit selector field for the volume column. **All four selectors target `note_vol`** — the per-note volume axis (§3, analog of IT's `chan->volume`). The per-channel axis (`channel_vol`) is reachable only via the M / N effects in the main effect column. The four selectors are:
 
-- **`0.$xx` — Set volume** to `$xx` (6-bit, $00..$3F). Equivalent to a note's default volume.
-- **`1.$xx` — Volume slide up** by `$xx` per non-first tick (4-bit). Volume clamps at $3F.
-- **`2.$xx` — Volume slide down** by `$xx` per non-first tick (4-bit). Volume clamps at $00.
-- **`3.$Sx` — Fine volume slide** on tick 0 only. The high bit `$S` of the value selects direction (0 = down, 1 = up); the low 4 bits `$x` ($0..$F) are the magnitude. Equivalent in scale to `D $xF00` / `D $Fy00` but with a 5-bit cap. Fires once per row regardless of speed.
+- **`0.$xx` — Set note_vol** to `$xx` (6-bit, $00..$3F). Equivalent in effect to seeding the note with a different default volume; persists across rows until the next re-trigger.
+- **`1.$xx` — note_vol slide up** by `$xx` per non-first tick (4-bit). Clamps at $3F. The slid value persists into following rows.
+- **`2.$xx` — note_vol slide down** by `$xx` per non-first tick (4-bit). Clamps at $00. The slid value persists into following rows.
+- **`3.$Sx` — Fine note_vol slide** on tick 0 only. The high bit `$S` of the value selects direction (0 = down, 1 = up); the low 4 bits `$x` ($0..$F) are the magnitude. Equivalent in scale to `D $xF00` / `D $Fy00` but with a 5-bit cap. Fires once per row regardless of speed.
 
-Volume-column effects do not consume the main effect slot; a cell can carry both (for instance, a tone portamento in the effect slot and a volume slide in the volume column).
+Volume-column effects do not consume the main effect slot; a cell can carry both (for instance, a tone portamento in the effect slot and a volume slide in the volume column). Because the volume column writes the per-note axis, an `M $xx00` on the same or following row sets the per-channel axis independently — the two multiply at the mixer (see §3 / §M).
 
-When the converter folds an ST3 K, L, M, or N effect into the volume column, the slide-up / slide-down nibbles map to selectors 1 / 2 (clamped to 6 bits — values above $3F clip).
+When the converter folds an ST3 K, L, M, or N effect into the volume column, the slide-up / slide-down nibbles map to selectors 1 / 2 (clamped to 6 bits — values above $3F clip). Note that *converted* M and N still target `note_vol` here (vol-col semantics) — to preserve the original per-channel intent, converters **MUST** emit them in the main effect column instead.
 
 NOTE: **`3.00` — is No-op**
 
@@ -1110,11 +1266,11 @@ The panning column uses the same 6-bit value + 2-bit selector layout:
 - **`2.$xx` — Pan slide left** by `$xx` per non-first tick (4-bit).
 - **`3.$Sx` — Fine pan slide** on tick 0 only, same direction-bit encoding as the volume column's selector 3.
 
-NOTE: **`3.00` — is No-op**. When Set Pan and S $80xx are both present, S-command takes precedence.
+NOTE: **`3.00` — is No-op**. When Set Pan and S $80xx are both present, S-command **MUST** take precedence.
 
 ---
 
-# Effects That Modifies Global Behaviour
+# Effects that modifies global behaviour
 
 Effects in this section modifies the behaviour of the mixer. Primary intention of the commands is to provide switches for legacy tracker and modern DAW behaviours.
 
@@ -1122,77 +1278,18 @@ Effects in this section modifies the behaviour of the mixer. Primary intention o
 
 **Plain.** Sets mixer-wide behaviour flags. Available flags are:
 
-    0b 0000 rr ff
+    0b 000 rrr ff
 
-- ff = 0: Linear tone mode. Pitch shift will behave like MIDI/ImpulseTracker/ScreamTracker linear mode. **Coarse and fine E/F arguments are stored as 4096-TET pitch units** and subtracted/added directly from the stored pitch.
-- ff = 1: Amiga (cycle-based) tone mode. Pitch shift will behave like ProTracker/ScreamTracker default mode. **Coarse and fine E/F arguments are stored as raw tracker period units** (the unscaled byte/nibble from the source PT/S3M/IT file) and applied in Amiga period space. Tone portamento (G) remains linear regardless of mode.
+- ff = 0: Linear tone mode. Pitch shift will behave like MIDI/ImpulseTracker. **Coarse and fine E/F arguments are stored as 4096-TET pitch units** and subtracted/added directly from the stored pitch.
+- ff = 1: Amiga (cycle-based) tone mode. Pitch shift will behave like ProTracker/ScreamTracker. **Coarse and fine E/F arguments are stored as raw tracker period units** (the unscaled byte/nibble from the source PT/S3M/IT file) and applied in Amiga period space. Tone portamento (G) remains linear regardless of mode.
 - ff = 2: Linear-frequency tone mode (MONOTONE compat). **E, F, and G arguments are stored as Hz/tick** (a signed change in audible frequency per song tick), and the engine converts the channel's stored 4096-TET pitch back to a frequency, adds/subtracts the argument, then converts back to 4096-TET. Reference is fixed at 12-TET A4 = 440 Hz / C4 ≈ 261.6256 Hz, which matches MONOTONE's MT_PLAY.PAS `notesHz` table (A0 = 27.5 Hz, equal-temperament). Unlike Amiga mode, *all three* slide effects use the new arithmetic — Monotone's `1xx`, `2xx`, and `3xx` are all in Hz/tick (see MTSRC/MT_PLAY.PAS:606-630).
 
-- rr = 0: Yes interpolation. Actual interpolation algorithm is implementation-dependent, but recommended to use either Fast Sinc or Linear.
-- rr = 1: No interpolation.
-- rr = 2: Amiga 500 interpolation.
-- rr = 3: Amiga 1200 interpolation.
-
-### Volume Fadeout
-
-Taud's volume fadeout is a single linear decay applied per song tick after key-off (or NNA Note-Fade). It is **the only retirement mechanism** for sustained voices when the volume envelope holds non-zero or has no terminating zero node — without a non-zero stored fadeout, such voices play forever.
-
-The 12-bit stored fadeout lives at instrument-record bytes 172 (low 8 bits) and 173 (low nibble = high 4 bits; high nibble reserved). Range 0..4095. The engine maintains a per-voice `fadeoutVolume ∈ [0, 1]` initialised to 1.0 on note-on, and once per song tick while the voice is keyed off:
-
-```
-fadeoutVolume -= storedFadeout / 1024.0
-clamp fadeoutVolume to [0, 1]
-if fadeoutVolume == 0: voice deactivates
-```
-
-Boundary semantics:
-
-| `storedFadeout` | Behaviour |
-| --- | --- |
-| `0` | No fade. Voice plays at envelope-driven volume indefinitely. |
-| `1..1023` | Graduated fade — completes in `1024 / storedFadeout` ticks. |
-| `1024` | Exact 1-tick cut. The canonical "kill on key-off" value. |
-| `1025..4095` | Also a 1-tick cut (clamped at 0). Headroom for converter robustness. |
-
-There is no separate "use fadeout" flag — both extremes share the same field, exactly as in the IT and XM file formats.
-
-**Tick-rate worked example** (default 50 Hz, BPM 125, speed 6):
-
-- `storedFadeout = 1` → fade ≈ 20.5 s
-- `storedFadeout = 32` → fade ≈ 640 ms
-- `storedFadeout = 1024` → ~20 ms (one tick)
-
-**Converter unit conversion.** Source trackers each expose fadeout in their own unit; converters scale the source value into Taud's 0..4095 field.
-
-- **IT** (`it2taud.py`): IT files store fadeout as a 16-bit field at instrument-record offset `0x14`, range 0..1024 per ITTECH (some loaders accept up to 2048). Schism's per-tick decrement is `stored / 1024` — identical to Taud's unit. **Pass-through with clamp:**
-  ```python
-  taud_fadeout = min(it_fadeout & 0xFFFF, 0x0FFF)
-  ```
-- **FT2 / XM** (`xm2taud.py`): XM files store fadeout as a 16-bit field. Spec range 0..0xFFF; MilkyTracker writes up to 32767 to encode the "cut" UI slider position (`SectionInstruments.cpp:499-500`). FT2's per-tick decrement is `stored / 32768` — to match Taud's `stored / 1024` rate, **divide source by 32 (round-to-nearest):**
-  ```python
-  taud_fadeout = min((xm_fadeout + 16) // 32, 0x0FFF)
-  ```
-  XM stored 1..15 round to Taud 0; the originals were >11 min at 50 Hz — effectively no-fade anyway. Stored 32 → Taud 1 (~20 s). Stored 32767 (Milky cut sentinel) → Taud 1024 (1-tick cut).
-- **MOD / S3M / MON**: source has no instrument-level fadeout. Converter writes Taud `0`. Notes retire on sample-end or pattern note-cut.
-
-**Implementation.**
-- Panning (equal-energy):
-  - L_gain = cos(πx / 512.0)
-  - R_gain = sin(πx / 512.0)
-- Amiga tone (both coarse and fine E/F pitch slides). The `slideArg` is a **raw tracker period-unit count** (no scaling), with sign matching linear mode (negative for E, positive for F). Coarse slides apply on every non-first tick; fine slides apply once on tick 0 — the per-step arithmetic is identical:
-  - AMIGA_BASE_PERIOD = 428.0  (period at the Taud reference pitch C4 for a standard 8363 Hz instrument, NTSC clock — identical to PT "C-2" period 428)
-  - period = AMIGA_BASE_PERIOD × 2^(−(noteVal − C4) / 4096)
-  - period_new = period − slideArg                     (E subtracts pitch ⇒ adds period; F adds pitch ⇒ subtracts period)
-  - noteVal_new = C4 + 4096 × log2(AMIGA_BASE_PERIOD / period_new)
-- Linear-frequency tone (E / F / G in Hz/tick). The `slideArg` is a **signed Hz delta per tick** at the audible reference 12-TET A4 = 440 Hz / C4 ≈ 261.6256 Hz, identical to the value MONOTONE stores in its 1xx/2xx/3xx commands. Sign convention matches linear/Amiga modes (negative for E, positive for F):
-  - LINEAR_FREQ_C4_HZ = 261.625565...  (12-TET, so A4 = 440 Hz exactly)
-  - freq = LINEAR_FREQ_C4_HZ × 2^((noteVal − C4) / 4096)
-  - freq_new = max(freq + slideArg, 1.0)
-  - noteVal_new = C4 + 4096 × log2(freq_new / LINEAR_FREQ_C4_HZ)
-  - For tone portamento (G), `tonePortaSpeed` is also in Hz/tick: each tick walks `freq` toward `noteValToFreq(target)` by `±tonePortaSpeed` until the target frequency is reached.
-  - Like Amiga mode, the per-voice intermediate frequency is cached across ticks (no round-trip rounding) and reseeded on note trigger, S$2x finetune, fine slides, and the start of a fresh multi-tick coarse slide.
-
-**Initialisation from the song table.** The same flags byte is stored in the song-table entry (see file format §Song Table). A Taud player should write this byte to MMIO playhead register 7 before starting playback; the mixer then applies it as the initial state on every reset, and subsequent in-pattern `1` effects may override it.
+- rrr = 0: Yes interpolation. The actual interpolation algorithm is implementation-dependent; Fast Sinc or Linear is **RECOMMENDED**.
+- rrr = 1: No interpolation.
+- rrr = 2: Amiga 500 interpolation.
+- rrr = 3: Amiga 1200 interpolation.
+- rrr = 4: SNES 4-tap gaussian.
+- rrr = 5: NES DPCM simulation.
 
 ---
 
@@ -1241,31 +1338,97 @@ This table maps each PT effect to its Taud equivalent. Arguments follow PT's two
 
 These quirks of ST3 are worth preserving or flagging when importing S3M files into Taud:
 
-**Shared memory across effects.** In ST3, a single memory slot backs D, E, F, I, J, K, L, Q, R, and S. A `$00` argument on any of these recalls whichever effect last wrote a non-zero argument. Taud narrows this to four cohorts (EF / G / HU / R) plus private slots. The converter must **eagerly resolve ST3 recalls** — walking the pattern in playback order, tracking the shared memory value, and emitting explicit Taud arguments wherever an ST3 recall crosses a cohort boundary. Otherwise a Taud player will either recall the wrong value or recall $0000.
+**Shared memory across effects.** In ST3, a single memory slot backs D, E, F, I, J, K, L, Q, R, and S. A `$00` argument on any of these recalls whichever effect last wrote a non-zero argument. Taud narrows this to four cohorts (EF / G / HU / R) plus private slots. The converter **MUST** **eagerly resolve ST3 recalls** — walking the pattern in playback order, tracking the shared memory value, and emitting explicit Taud arguments wherever an ST3 recall crosses a cohort boundary. Otherwise a Taud player will either recall the wrong value or recall $0000.
 
 **M / N / P (channel volume and panning).** S3M files produced by IT-aware tools embed M (set channel volume), N (channel volume slide), and P (channel panning slide) using the IT semantics described in §M / §N / §P. These are emitted verbatim into Taud (with M's argument byte clamped to $3F). N and P each have private memory; M is literal-zero. ST3 itself never wrote M / N / P, so legacy S3M files contain none.
 
-**Cxx BCD encoding.** ST3 stores pattern-break row numbers as BCD on disk (`$10` means decimal 10). Taud uses binary. Decode on import; encode on export. Out-of-range BCD bytes (decimal 64 or higher) clamp to row 0.
+**Cxx BCD encoding.** ST3 stores pattern-break row numbers as BCD on disk (`$10` means decimal 10). Taud uses binary. Converters **MUST** decode on import and encode on export. Out-of-range BCD bytes (decimal 64 or higher) **SHOULD** clamp to row 0.
 
-**Tempo range.** ST3 accepts tempos $20..$FF (BPM 32..255); Taud accepts bytes $00..$FF (BPM 24..279). Imported ST3 tempos must be shifted down by $18; Taud tempos below $08 and above $E7 cannot be represented in ST3 and should clamp on export.
+**Tempo range.** ST3 accepts tempos $20..$FF (BPM 32..255); Taud accepts bytes $00..$FF (BPM 25..280). Imported ST3 tempos **MUST** be shifted down by $19; Taud tempos below $07 and above $E6 cannot be represented in ST3 and **SHOULD** clamp on export.
 
-**SBx + SEx interaction.** ST3 miscounts loop iterations when pattern delay is active inside a pattern loop; Taud fixes this. Songs that depended on the bug for their intended playback will loop fewer times in Taud. Flag such songs on import.
+**SBx + SEx interaction.** ST3 miscounts loop iterations when pattern delay is active inside a pattern loop; Taud fixes this. Songs that depended on the bug for their intended playback will loop fewer times in Taud. Converters **SHOULD** flag such songs on import.
 
-**Simultaneous SEx priority.** ST3 uses pan order (L1..L8, R1..R8); Taud uses ascending channel-index order. Rare; flag on import if multiple channels carry SEx in the same row.
+**Simultaneous SEx priority.** ST3 uses pan order (L1..L8, R1..R8); Taud uses ascending channel-index order. Rare; converters **SHOULD** flag on import if multiple channels carry SEx in the same row.
 
-**Muted channels.** ST3 skips all effect processing on muted channels (no volume change, no tempo change, no jumps); Taud follows this rule for strict compatibility but recommends that new compositions avoid muting channels that carry global effects.
+**Muted channels.** ST3 skips all effect processing on muted channels (no volume change, no tempo change, no jumps); Taud **MUST** follow this rule for strict compatibility, but new compositions **SHOULD NOT** mute channels that carry global effects.
 
 **Volume cap.** ST3's volume caps at $40; Taud's at $3F. Notes that reached $40 in ST3 (a rare edge) will play marginally quieter in Taud.
 
-**Global volume scale.** ST3's 0..$40 maps to Taud's 0..$FF with a ×4 scale on import, truncated ÷4 on export.
+**Global volume scale.** ST3's 0..$40 maps to Taud's 0..$FF with a ×4 scale on import and a truncated ÷4 on export. Converters **MUST** apply these scales.
 
-**Linear pitch slides.** ST3's slide arithmetic is period-based (Amiga) or linear-table-indexed; Taud carries both interpretations and selects between them via the song-table `f` flag. Conversion rules:
+**Linear pitch slides.** ST3's slide arithmetic is period-based; Taud supports both linear and period-based and selects between them via the song-table `f` flag. Conversion rules:
 
-- **ST3 linear mode** (`linear_slides` set in S3M flags): coarse forms (Exx/Fxx) use `round(× 64/3)` (1/16 semitone per ST3 unit); fine/extra-fine (EFx/EEx/FFx/FEx) use `round(× 16/3)` (1/64 semitone per ST3 unit). Taud `f` flag is **clear**; the engine subtracts the stored 4096-TET argument directly from the channel pitch.
-- **ST3 Amiga mode** (`linear_slides` clear): both coarse (Exx/Fxx) and fine/extra-fine (EFx/EEx/FFx/FEx) are stored **verbatim** as raw ST3 period units — coarse as `E/F $00xx`, fine as `E/F $F00x` — with no scaling. Taud `f` flag is **set**; the engine applies both forms in Amiga period space at playback, exactly recovering the source's period-step count and the non-linear pitch character.
-- G (tone portamento) is always converted with `round(× 64/3)` and treated as linear, regardless of mode.
+- Clear `linear_slides`. Both coarse (Exx/Fxx) and fine/extra-fine (EFx/EEx/FFx/FEx) are stored **verbatim** as raw ST3 period units — coarse as `E/F $00xx`, fine as `E/F $F00x` — with no scaling. Taud `f` flag is **set**; the engine applies both forms in Amiga period space at playback, exactly recovering the source's period-step count and the non-linear pitch character.
+- G (tone portamento) **MUST** always be converted with `round(× 64/3)` and treated as linear, regardless of mode.
 
-**Default tempo byte.** Taud's default $65 equals 125 BPM under the $18 offset; this is not the same as ST3's `$7D` default, which maps to Taud `$65` after subtracting $18. Converters must remap on both import and export.
+**Default tempo byte.** Taud's default $64 equals 125 BPM under the $19 offset; this is not the same as ST3's `$7D` default, which maps to Taud `$64` after subtracting $19. Converters **MUST** remap on both import and export.
+
+---
+
+# Miscellaneous implementation details
+
+This section documents important implementation details that are not covered by sections above.
+
+## Volume fadeout
+
+Taud's volume fadeout is a single linear decay applied per song tick after key-off (or NNA Note-Fade). It is **the only retirement mechanism** for sustained voices when the volume envelope holds non-zero or has no terminating zero node — without a non-zero stored fadeout, such voices play forever.
+
+The 12-bit stored fadeout lives at instrument-record bytes 172 (low 8 bits) and 173 (low nibble = high 4 bits; high nibble reserved). Range 0..4095. The engine **MUST** maintain a per-voice `fadeoutVolume ∈ [0, 1]` initialised to 1.0 on note-on, and once per song tick while the voice is keyed off **MUST**:
+
+```
+fadeoutVolume -= storedFadeout / 1024.0
+clamp fadeoutVolume to [0, 1]
+if fadeoutVolume == 0: voice deactivates
+```
+
+Boundary semantics:
+
+| `storedFadeout` | Behaviour |
+| --- | --- |
+| `0` | No fade. Voice plays at envelope-driven volume indefinitely. |
+| `1..1023` | Graduated fade — completes in `1024 / storedFadeout` ticks. |
+| `1024` | Exact 1-tick cut. The canonical "kill on key-off" value. |
+| `1025..4095` | Also a 1-tick cut (clamped at 0). Headroom for converter robustness. |
+
+There is no separate "use fadeout" flag — both extremes share the same field, exactly as in the IT and XM file formats.
+
+**Tick-rate worked example** (default 50 Hz, BPM 125, speed 6):
+
+- `storedFadeout = 1` → fade ≈ 20.5 s
+- `storedFadeout = 32` → fade ≈ 640 ms
+- `storedFadeout = 1024` → ~20 ms (one tick)
+
+**Converter unit conversion.** Source trackers each expose fadeout in their own unit; converters **MUST** scale the source value into Taud's 0..4095 field.
+
+- **IT** (`it2taud.py`): IT files store fadeout as a 16-bit field at instrument-record offset `0x14`, range 0..1024 per ITTECH (some loaders accept up to 2048). Schism's per-tick decrement is `stored / 1024` — identical to Taud's unit. **Pass-through with clamp:**
+  ```python
+  taud_fadeout = min(it_fadeout & 0xFFFF, 0x0FFF)
+  ```
+- **FT2 / XM** (`xm2taud.py`): XM files store fadeout as a 16-bit field. Spec range 0..0xFFF; MilkyTracker writes up to 32767 to encode the "cut" UI slider position (`SectionInstruments.cpp:499-500`). FT2's per-tick decrement is `stored / 32768` — to match Taud's `stored / 1024` rate, **divide source by 32 (round-to-nearest):**
+  ```python
+  taud_fadeout = min((xm_fadeout + 16) // 32, 0x0FFF)
+  ```
+  XM stored 1..15 round to Taud 0; the originals were >11 min at 50 Hz — effectively no-fade anyway. Stored 32 → Taud 1 (~20 s). Stored 32767 (Milky cut sentinel) → Taud 1024 (1-tick cut).
+- **MOD / S3M / MON**: source has no instrument-level fadeout. Converter writes Taud `0`. Notes retire on sample-end or pattern note-cut.
+
+**Implementation.**
+- Panning (equal-energy):
+  - L_gain = cos(πx / 512.0)
+  - R_gain = sin(πx / 512.0)
+- Amiga tone (both coarse and fine E/F pitch slides). The `slideArg` is a **raw tracker period-unit count** (no scaling), with sign matching linear mode (negative for E, positive for F). Coarse slides apply on every non-first tick; fine slides apply once on tick 0 — the per-step arithmetic is identical:
+  - AMIGA_BASE_PERIOD = 428.0  (period at the Taud reference pitch C4 for a standard 8363 Hz instrument, NTSC clock — identical to PT "C-2" period 428)
+  - period = AMIGA_BASE_PERIOD × 2^(−(noteVal − C4) / 4096)
+  - period_new = period − slideArg                     (E subtracts pitch ⇒ adds period; F adds pitch ⇒ subtracts period)
+  - noteVal_new = C4 + 4096 × log2(AMIGA_BASE_PERIOD / period_new)
+- Linear-frequency tone (E / F / G in Hz/tick). The `slideArg` is a **signed Hz delta per tick** at the audible reference 12-TET A4 = 440 Hz / C4 ≈ 261.6256 Hz, identical to the value MONOTONE stores in its 1xx/2xx/3xx commands. Sign convention matches linear/Amiga modes (negative for E, positive for F):
+  - LINEAR_FREQ_C4_HZ = 261.625565...  (12-TET, so A4 = 440 Hz exactly)
+  - freq = LINEAR_FREQ_C4_HZ × 2^((noteVal − C4) / 4096)
+  - freq_new = max(freq + slideArg, 1.0)
+  - noteVal_new = C4 + 4096 × log2(freq_new / LINEAR_FREQ_C4_HZ)
+  - For tone portamento (G), `tonePortaSpeed` is also in Hz/tick: each tick walks `freq` toward `noteValToFreq(target)` by `±tonePortaSpeed` until the target frequency is reached.
+  - Like Amiga mode, the per-voice intermediate frequency is cached across ticks (no round-trip rounding) and reseeded on note trigger, S$2x finetune, fine slides, and the start of a fresh multi-tick coarse slide.
+
+**Initialisation from the song table.** The same flags byte is stored in the song-table entry (see file format §Song Table). A Taud player **MUST** write this byte to MMIO playhead register 7 before starting playback; the mixer then applies it as the initial state on every reset, and subsequent in-pattern `1` effects **MAY** override it.
 
 ---
 

assets/disk0/!BOOTSEC

@@ -1 +1 @@
-let p=_BIOS.FIRST_BOOTABLE_PORT;com.sendMessage(p[0],"DEVRST\x17");com.sendMessage(p[0],'OPENR"tvdos/hyve.SYS",'+p[1]);let r=com.getStatusCode(p[0]);if(0==r)if(com.sendMessage(p[0],"READ"),r=com.getStatusCode(p[0]),0==r){let g=com.pullMessage(p[0]);eval(g)}else println("I/O Error");else println("TVDOS.SYS not found");println("Shutting down...");println("It is now safe to turn off the power")
+let p=_BIOS.FIRST_BOOTABLE_PORT;com.sendMessage(p[0],"DEVRST\x17");com.sendMessage(p[0],'OPENR"tvdos/TVDOS.SYS",'+p[1]);let r=com.getStatusCode(p[0]);if(0==r)if(com.sendMessage(p[0],"READ"),r=com.getStatusCode(p[0]),0==r){let g=com.pullMessage(p[0]);eval(g)}else println("I/O Error");else println("TVDOS.SYS not found");println("Shutting down...");println("It is now safe to turn off the power")

assets/disk0/AUTOEXEC.BAT

@@ -1,10 +1,11 @@
-echo "Starting TVDOS..."
-
-rem put set-xxx commands here:
-set PATH=\tvdos\installer;\tvdos\tuidev;$PATH
-set KEYBOARD=us_colemak
-
-rem this line specifies which shell to be presented after the boot precess:
+rem AUTOEXEC.BAT -- per-console launch script. Run once for every console:
+rem each virtual-console pane runs it (via vtmgr's bootstrap), and the boot
+rem shell runs it as the fallback once vtmgr exits (Alt-0). Environment setup
+rem (`set` commands) lives in \commandrc, which TVDOS.SYS runs before this.
+rem
+rem Korean IME registers a per-CONTEXT handler (unicode.uniprint), so it must
+rem run per-console here rather than once at boot.
 tvdos/i18n/korean
-zfm
+
+rem The interactive shell for this console.
 command -fancy

assets/disk0/COPYING

@@ -1,4 +1,4 @@
-Copyright (c) 2020-2024 CuriousTorvald
+Copyright (c) 2020-2026 CuriousTorvald
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

assets/disk0/commandrc

@@ -0,0 +1,9 @@
+rem commandrc -- environment setup, run by TVDOS.SYS in EVERY context
+rem (the boot shell AND every virtual-console pane). Put `set` commands and
+rem other env-only configuration here. Do NOT launch apps from this file:
+rem app launches belong in AUTOEXEC.BAT (run per-console by vtmgr).
+
+set PATH=\tvdos\installer;\tvdos\tuidev;\tbas;\hopper\bin;$PATH
+set INCLPATH=\hopper\include;$INCLPATH
+set HELPPATH=\hopper\help;$HELPPATH
+set KEYBOARD=us_colemak

assets/disk0/etc/motd

@@ -1,3 +1,3 @@
-TVDOS (c) 2020-2024 CuriousTorvald
+TVDOS (c) 2020-2026 CuriousTorvald
 
 TVDOS is provided "as is", without warranty of any kind; in no event shall the authors or copyright holders be liable for any claim, damages or other liabilities. Run 'less COPYING' for more information.

assets/disk0/home/fsh.js

@@ -1,24 +1,181 @@
-graphics.setBackground(2,1,3);
-graphics.resetPalette();
+graphics.setBackground(2,1,3)
+graphics.resetPalette()
+const GL = require("gl")
+const win = require("wintex")
+const keysym = require("keysym")
 
 function captureUserInput() {
-    sys.poke(-40, 1);
+    sys.poke(-40, 1)
 }
 
 function getKeyPushed(keyOrder) {
-    return sys.peek(-41 - keyOrder);
+    return sys.peek(-41 - keyOrder)
 }
 
-let _fsh = {};
-_fsh.titlebarTex = new GL.Texture(2, 14, base64.atob("/u/+/v3+/f39/f39/f39/f39/P39/Pz8/Pv7+w=="));
-_fsh.scrdim = con.getmaxyx();
-_fsh.scrwidth = _fsh.scrdim[1];
-_fsh.scrheight = _fsh.scrdim[0];
-_fsh.brandName = "f\xb3Sh";
+function readMousePos() {
+    let lx = sys.peek(-33) & 0xFF
+    let hx = sys.peek(-34) & 0xFF
+    let ly = sys.peek(-35) & 0xFF
+    let hy = sys.peek(-36) & 0xFF
+    return [(hx << 8) | lx, (hy << 8) | ly]
+}
+
+function readMouseButtons() {
+    return sys.peek(-37) & 0xFF
+}
+
+// Returns true if any of the eight key event buffer slots holds keycode `kc`.
+function isKeyDown(kc) {
+    for (let i = 0; i < 8; i++) {
+        if ((sys.peek(-41 - i) & 0xFF) === kc) return true
+    }
+    return false
+}
+
+let _fsh = {}
+
+// Config file path
+_fsh.CONFIG_PATH = "A:/home/config/fshrc"
+
+// Widget row caps (must match the loop bounds in draw())
+_fsh.TODO_MAX_ROWS = 13       // todoWidget draws i = 0..12
+_fsh.QA_MAX_ROWS = 22         // quickAccessWidget draws i = 0..21
+_fsh.TODO_TEXT_WIDTH = 24     // visible characters per todo row
+_fsh.QA_LABEL_WIDTH = 24      // visible characters per QA label
+_fsh.QA_CMD_WIDTH = 60        // command path field width in dialog
+
+// Highlight foreground for keyboard focus on widget lists. The background
+// stays transparent (255) so the wallpaper continues to show through.
+_fsh.HL_FG = 230
+_fsh.HL_BG = 255
+
+// Default Quick Access entries when fshrc is missing or empty
+_fsh.DEFAULT_QA = [
+    ["Files",     "/tvdos/bin/zsh.js"],
+    ["Editor",    "/tvdos/bin/edit.js"],
+    ["BASIC",     "/tbas/basic.js"],
+    ["DOS Shell", "/tvdos/bin/command.js /fancy"]
+]
+
+// Mouse button bits (MMIO[36] layout per IOSpace.kt)
+_fsh.MB_LEFT = 1
+_fsh.MB_RIGHT = 2
+
+// Current focus: null or {widgetId: string, index: number}.
+// Index uses the same convention as hitTest: 0..length-1 are entries,
+// `length` is the "+ Click to add" row.
+_fsh.focus = null
+
+// Parse fshrc text into {todos: [[text, done], ...], qa: [[label, cmd], ...]}.
+// Returns null for both arrays when input is empty/whitespace.
+_fsh.parseConfig = function(text) {
+    let todos = []
+    let qa = []
+    let section = null
+    if (!text) return {todos: todos, qa: qa}
+    let lines = text.split("\n")
+    for (let i = 0; i < lines.length; i++) {
+        let line = lines[i]
+        // strip trailing \r if any
+        if (line.length && line.charCodeAt(line.length - 1) === 13) {
+            line = line.substring(0, line.length - 1)
+        }
+        if (line.length === 0) continue
+        if (line.charAt(0) === "[") {
+            let close = line.indexOf("]")
+            if (close > 0) {
+                let name = line.substring(1, close).trim().toUpperCase()
+                if (name === "TODO" || name === "QUICK_ACCESS") section = name
+                else section = null  // unknown section: ignore until next header
+            }
+            continue
+        }
+        if (section === "TODO") {
+            if (line.length < 2) continue
+            let marker = line.charAt(0)
+            if ((marker === "+" || marker === "-") && line.charAt(1) === " ") {
+                todos.push([line.substring(2), marker === "+"])
+            }
+        } else if (section === "QUICK_ACCESS") {
+            let comma = line.indexOf(",")
+            if (comma <= 0) continue     // need a non-empty label
+            let label = line.substring(0, comma)
+            let cmd = line.substring(comma + 1)
+            qa.push([label, cmd])
+        }
+    }
+    return {todos: todos, qa: qa}
+}
+
+// Build fshrc text from in-memory model. Inverse of parseConfig.
+_fsh.serializeConfig = function(todos, qa) {
+    let out = "[TODO]\n"
+    for (let i = 0; i < todos.length; i++) {
+        let t = todos[i]
+        out += (t[1] ? "+ " : "- ") + t[0] + "\n"
+    }
+    out += "\n[QUICK_ACCESS]\n"
+    for (let i = 0; i < qa.length; i++) {
+        out += qa[i][0] + "," + qa[i][1] + "\n"
+    }
+    return out
+}
+
+// Read fshrc; populate todoWidget.todoList and quickAccessWidget.entries.
+// Falls back to defaults on missing/empty/malformed file.
+_fsh.loadConfig = function() {
+    let f = files.open(_fsh.CONFIG_PATH)
+    let parsed = {todos: [], qa: []}
+    if (f.exists) {
+        try {
+            parsed = _fsh.parseConfig(f.sread())
+        } catch (e) {
+            serial.printerr("fsh.loadConfig: parse failed: " + e)
+            parsed = {todos: [], qa: []}
+        }
+    }
+    todoWidget.todoList = parsed.todos
+    quickAccessWidget.entries = (parsed.qa.length > 0)
+        ? parsed.qa
+        : _fsh.DEFAULT_QA.slice()   // copy so saves don't mutate the constant
+}
+
+// Persist the current in-memory todos + QA entries to fshrc.
+_fsh.saveConfig = function() {
+    try {
+        let f = files.open(_fsh.CONFIG_PATH)
+        if (!f.exists) f.mkFile()
+        f.swrite(_fsh.serializeConfig(todoWidget.todoList, quickAccessWidget.entries))
+    } catch (e) {
+        serial.printerr("fsh.saveConfig: write failed: " + e)
+    }
+}
+
+
+// Map (mouse char x, mouse char y) to a row index for a widget drawn at
+// (xoff, yoff) with `length` existing entries and `maxRows` total rows.
+// Returns null / {kind:"add"} / {kind:"item", index: i}.
+_fsh.hitTestList = function(charX, charY, xoff, yoff, textWidth, length, maxRows) {
+    // Each row sits at (yoff + i + 2, xoff..xoff + textWidth + 1).
+    // Column range: icon at xoff, text at xoff+2 .. xoff+1+textWidth.
+    // Allow clicks anywhere on the row's char cells (icon + text region).
+    let relY = charY - yoff - 2
+    if (relY < 0 || relY >= maxRows) return null
+    if (charX < xoff || charX > xoff + 1 + textWidth) return null
+    if (relY < length) return {kind: "item", index: relY}
+    if (relY === length) return {kind: "add"}
+    return null
+}
+
+_fsh.titlebarTex = new GL.Texture(2, 14, base64.atob("/u/+/v3+/f39/f39/f39/f39/P39/Pz8/Pv7+w=="))
+_fsh.scrdim = con.getmaxyx()
+_fsh.scrwidth = _fsh.scrdim[1]
+_fsh.scrheight = _fsh.scrdim[0]
+_fsh.brandName = "f\xb3Sh"
 _fsh.brandLogoTexSmall = new GL.Texture(24, 14, gzip.decomp(base64.atob(
 "H4sIAAAAAAAAAPv/Hy/4Qbz458+fIeILQQBIwoSh6qECuMVBukCmIJkDVQ+RQNgLE0MX/w+1lyhxqIUwTLJ/sQMAcIXsbVABAAA="
-)));
-_fsh.scrlayout = ["com.fsh.clock","com.fsh.calendar","com.fsh.todo_list", "com.fsh.quick_access"];
+)))
+_fsh.scrlayout = ["com.fsh.clock","com.fsh.calendar","com.fsh.todo_list", "com.fsh.quick_access"]
 
 _fsh.drawWallpaper = function() {
     let wp = files.open("A:/home/wall.bytes")
@@ -28,85 +185,85 @@ _fsh.drawWallpaper = function() {
     wp.pread(b, 250880, 0)
     dma.ramToFrame(b, 0, 250880)
     sys.free(b)
-};
+}
 
 _fsh.drawTitlebar = function(titletext) {
-    GL.drawTexPattern(_fsh.titlebarTex, 0, 0, 560, 14);
+    GL.drawTexPattern(_fsh.titlebarTex, 0, 0, 560, 14)
     if (titletext === undefined || titletext.length == 0) {
-        con.move(1,1);
-        print(" ".repeat(_fsh.scrwidth));
-        GL.drawTexImageOver(_fsh.brandLogoTexSmall, 268, 0);
+        con.move(1,1)
+        print(" ".repeat(_fsh.scrwidth))
+        GL.drawTexImageOver(_fsh.brandLogoTexSmall, 268, 0)
     }
     else {
-        con.color_pair(240, 255);
-        GL.drawTexPattern(_fsh.titlebarTex, 268, 0, 24, 14);
-        con.move(1, 1 + (_fsh.scrwidth - titletext.length) / 2);
-        print(titletext);
+        con.color_pair(240, 255)
+        GL.drawTexPattern(_fsh.titlebarTex, 268, 0, 24, 14)
+        con.move(1, 1 + (_fsh.scrwidth - titletext.length) / 2)
+        print(titletext)
     }
-    con.color_pair(254, 255);
-};
+    con.color_pair(254, 255)
+}
 
 
 _fsh.Widget = function(id, w, h) {
-    this.identifier = id;
-    this.width = w;
-    this.height = h;
+    this.identifier = id
+    this.width = w
+    this.height = h
 
     if (!this.identifier) {
-        this.identifier = "";
+        this.identifier = ""
     }
 
-    //this.update = function() {};
+    //this.update = function() {}
     /**
      * Params charXoff and charYoff are ZERO-BASED!
      */
-    this.draw = function(charXoff, charYoff) {};
+    this.draw = function(charXoff, charYoff) {}
 }
 
 _fsh.widgets = {}
 _fsh.registerNewWidget = function(widget) {
-    _fsh.widgets[widget.identifier] = widget;
+    _fsh.widgets[widget.identifier] = widget
 }
 
-let clockWidget = new _fsh.Widget("com.fsh.clock", _fsh.scrwidth - 8, 7*2);
+let clockWidget = new _fsh.Widget("com.fsh.clock", _fsh.scrwidth - 8, 7*2)
 clockWidget.numberSheet = new GL.SpriteSheet(19, 22, new GL.Texture(190, 22, gzip.decomp(base64.atob(
 "H4sIAAAAAAAAAMWVW3LEMAgE739aHcFJJV5ZMD2I9ToVfcl4GBr80HF8r/FaR1ozMuIyoUu87lEXI0al5qVR5AebSwchSaNE6Nyo1Nw5HXF3SfPT4Bshl"+
 "EycA8RD96mLlHbuhTgOrfLnUDZspafbSQWk56WEGvQEtWaWwgb8iz7a8AOXhsraO/q9Qw2/GnXovfVN+q2wM/p/oddn2cjF239GX3y11+SWCtc6FTHC1v"+
 "TVPkDPWWn0w+DDz93UX9v9mF5KIsQ6OdN2KJoB4ui1bXXr0AMp0YfiQo//4XhpK8555dsNehAqVS5uhb5iHn3Kko769J59KmLBe/TSR7hcsd+hr+HnrwR"+
 "9uvRF9+D3MP14gN7lqx+8OuNT+uqt3NFX3SN9fTbeeHNq+C29pRWzX5+Rcm7SZyjOKJ/2hkSPqul4xN279DrSYvCrNu2NI7ZMp1ouBxK3KBVVnEeAUWbK"+
 "MUDn5DPsPxmUqHZQjGpy2hergM3EVBAAAA=="
-))));
+))))
 
-clockWidget.clockColon = new GL.Texture(4, 3, base64.atob("7+/v7+/v7+/v7+/v"));
-clockWidget.monthNames = ["Spring", "Summer", "Autumn", "Winter"];
-clockWidget.dayNames = ["Mondag  ", "Tysdag  ", "Midtveke", "Torsdag ", "Fredag  ", "Laurdag ", "Sundag  ", "Verddag "];
+clockWidget.clockColon = new GL.Texture(4, 3, base64.atob("7+/v7+/v7+/v7+/v"))
+clockWidget.monthNames = ["Spring", "Summer", "Autumn", "Winter"]
+clockWidget.dayNames = ["Mondag  ", "Tysdag  ", "Midtveke", "Torsdag ", "Fredag  ", "Laurdag ", "Sundag  ", "Verddag "]
 clockWidget.draw = function(charXoff, charYoff) {
-    con.color_pair(254, 255);
-    let xoff = charXoff * 7;
-    let yoff = charYoff * 14 + 3;
-    let timeInMinutes = ((sys.currentTimeInMills() / 60000)|0);
-    let mins = timeInMinutes % 60;
-    let hours = ((timeInMinutes / 60)|0) % 24;
-    let ordinalDay = ((timeInMinutes / (60*24))|0) % 120;
-    let visualDay = (ordinalDay % 30) + 1;
-    let months = ((timeInMinutes / (60*24*30))|0) % 4;
-    let dayName = ordinalDay % 7; // 0 for Mondag
-    if (ordinalDay == 119) dayName = 7; // Verddag
-    let years = ((timeInMinutes / (60*24*30*120))|0) + 125;
+    con.color_pair(254, 255)
+    let xoff = charXoff * 7
+    let yoff = charYoff * 14 + 3
+    let timeInMinutes = ((sys.currentTimeInMills() / 60000)|0)
+    let mins = timeInMinutes % 60
+    let hours = ((timeInMinutes / 60)|0) % 24
+    let ordinalDay = ((timeInMinutes / (60*24))|0) % 120
+    let visualDay = (ordinalDay % 30) + 1
+    let months = ((timeInMinutes / (60*24*30))|0) % 4
+    let dayName = ordinalDay % 7 // 0 for Mondag
+    if (ordinalDay == 119) dayName = 7 // Verddag
+    let years = ((timeInMinutes / (60*24*30*120))|0) + 125
     // draw timepiece
-    GL.drawSprite(clockWidget.numberSheet, (hours / 10)|0, 0, xoff, yoff, 1);
-    GL.drawSprite(clockWidget.numberSheet, hours % 10, 0, xoff + 24, yoff, 1);
-    GL.drawTexImage(clockWidget.clockColon, xoff + 48, yoff + 5, 1);
-    GL.drawTexImage(clockWidget.clockColon, xoff + 48, yoff + 14, 1);
-    GL.drawSprite(clockWidget.numberSheet, (mins / 10)|0, 0, xoff + 57, yoff, 1);
-    GL.drawSprite(clockWidget.numberSheet, mins % 10, 0, xoff + 81, yoff, 1);
+    GL.drawSprite(clockWidget.numberSheet, (hours / 10)|0, 0, xoff, yoff, 1)
+    GL.drawSprite(clockWidget.numberSheet, hours % 10, 0, xoff + 24, yoff, 1)
+    GL.drawTexImage(clockWidget.clockColon, xoff + 48, yoff + 5, 1)
+    GL.drawTexImage(clockWidget.clockColon, xoff + 48, yoff + 14, 1)
+    GL.drawSprite(clockWidget.numberSheet, (mins / 10)|0, 0, xoff + 57, yoff, 1)
+    GL.drawSprite(clockWidget.numberSheet, mins % 10, 0, xoff + 81, yoff, 1)
     // print month and date
-    con.move(1 + charYoff, 17 + charXoff);
-    print(clockWidget.monthNames[months]+" "+visualDay);
+    con.move(1 + charYoff, 17 + charXoff)
+    print(clockWidget.monthNames[months]+" "+visualDay)
     // print year and dayname
-    con.move(2 + charYoff, 17 + charXoff);
-    print("\xE7"+years+" "+clockWidget.dayNames[dayName]);
-};
+    con.move(2 + charYoff, 17 + charXoff)
+    print("\xE7"+years+" "+clockWidget.dayNames[dayName])
+}
 
 
 let calendarWidget = new _fsh.Widget("com.fsh.calendar", (_fsh.scrwidth - 8) / 2, 7*6)
@@ -171,70 +328,284 @@ calendarWidget.draw = function(charXoff, charYoff) {
 let todoWidget = new _fsh.Widget("com.fsh.todo_list", (_fsh.scrwidth - 8) / 2, 7*10)
 todoWidget.todoList = [["Hello, world!", true]]
 todoWidget.draw = function(charXoff, charYoff) {
+    let focusIndex = (_fsh.focus && _fsh.focus.widgetId === todoWidget.identifier)
+        ? _fsh.focus.index : -1
+
     con.color_pair(254, 255)
     let xoff = charXoff * 7
     let yoff = charYoff * 14 + 3
 
     con.move(charYoff, charXoff)
-    print("========== TODO ==========")
+    print('\u00CD'.repeat(10)+" TODO "+'\u00CD'.repeat(10))
 
     for (let i = 0; i <= 12; i++) {
-        let list = todoWidget.todoList[i] || ["Click to add", null]
+        let list = todoWidget.todoList[i] || ["Click to add"+" ".repeat(_fsh.TODO_TEXT_WIDTH - 12), null]
+        let isFocused = (i === focusIndex)
 
-        if (list[1] === null) con.color_pair(249, 255)
+        if (isFocused) con.color_pair(_fsh.HL_FG, _fsh.HL_BG)
+        else if (list[1] === null) con.color_pair(249, 255)
         else con.color_pair(254, 255)
 
         con.move(charYoff + i + 2, charXoff)
         con.addch((list[1] === null) ? 43 : (list[1]) ? 0x9F : 0x9E)
 
         if (i > todoWidget.todoList.length) {
+            // Filler row \u2014 keep underscores but don't highlight (can't focus here)
+            con.color_pair(254, 255)
             for (let k = 0; k < 24; k++) {
                 con.mvaddch(charYoff + i + 2, charXoff + 2 + k, 95)
             }
         }
         else {
             con.move(charYoff + i + 2, charXoff + 2)
-            print(`${list[0]}`)
+            // Pad text to TODO_TEXT_WIDTH so the highlight bar covers full row
+            let text = `${list[0]}`
+            if (text.length > _fsh.TODO_TEXT_WIDTH) text = text.substring(0, _fsh.TODO_TEXT_WIDTH)
+            if (isFocused) text = text + " ".repeat(_fsh.TODO_TEXT_WIDTH - text.length)
+            print(text)
         }
     }
 }
 
 let quickAccessWidget = new _fsh.Widget("com.fsh.quick_access", (_fsh.scrwidth - 8) / 2, 7*20)
-quickAccessWidget.entries = [
-    ["Files", "/tvdos/bin/explorer.js"],
+quickAccessWidget.entries = [ // TODO read from /home/config/fshrc
+    ["Files", "/tvdos/bin/zfm.js"],
     ["Editor", "/tvdos/bin/edit.js"],
     ["BASIC", "/tbas/basic.js"],
-    ["DOS Shell", "/tvdos/bin/command.js /fancy"]
+    ["DOS Shell", "/tvdos/bin/command.js -fancy"]
 ]
 quickAccessWidget.draw = function(charXoff, charYoff) {
+    let focusIndex = (_fsh.focus && _fsh.focus.widgetId === quickAccessWidget.identifier)
+        ? _fsh.focus.index : -1
+
     con.color_pair(254, 255)
     let xoff = charXoff * 7
     let yoff = charYoff * 14 + 3
 
     con.move(charYoff, charXoff)
-    print("====== QUICK ACCESS ======")
+    print('\u00CD'.repeat(6)+" QUICK ACCESS "+'\u00CD'.repeat(6))
 
     for (let i = 0; i <= 21; i++) {
-        let list = quickAccessWidget.entries[i] || ["Click to add", null]
+        let list = quickAccessWidget.entries[i] || ["Click to add"+" ".repeat(_fsh.QA_LABEL_WIDTH - 12), null]
+        let isFocused = (i === focusIndex)
 
-        if (list[1] === null) con.color_pair(249, 255)
+        if (isFocused) con.color_pair(_fsh.HL_FG, _fsh.HL_BG)
+        else if (list[1] === null) con.color_pair(249, 255)
         else con.color_pair(254, 255)
 
         con.move(charYoff + i + 2, charXoff)
         con.addch((list[1] === null) ? 0xF9 : (list[1]) ? 7 : 0x7F)
 
         if (i > quickAccessWidget.entries.length) {
+            con.color_pair(254, 255)
             for (let k = 0; k < 24; k++) {
                 con.mvaddch(charYoff + i + 2, charXoff + 2 + k, 95)
             }
         }
         else {
             con.move(charYoff + i + 2, charXoff + 2)
-            print(`${list[0]}`)
+            let text = `${list[0]}`
+            if (text.length > _fsh.QA_LABEL_WIDTH) text = text.substring(0, _fsh.QA_LABEL_WIDTH)
+            if (isFocused) text = text + " ".repeat(_fsh.QA_LABEL_WIDTH - text.length)
+            print(text)
         }
     }
 }
 
+todoWidget.hitTest = function(charX, charY, xoff, yoff) {
+    return _fsh.hitTestList(charX, charY, xoff, yoff,
+        _fsh.TODO_TEXT_WIDTH, todoWidget.todoList.length, _fsh.TODO_MAX_ROWS)
+}
+
+quickAccessWidget.hitTest = function(charX, charY, xoff, yoff) {
+    return _fsh.hitTestList(charX, charY, xoff, yoff,
+        _fsh.QA_LABEL_WIDTH, quickAccessWidget.entries.length, _fsh.QA_MAX_ROWS)
+}
+
+
+// Re-render the whole shell. Use after a dialog closes (which clobbered
+// the underlying char cells) or after execApp returns.
+_fsh.redrawAll = function() {
+    con.color_pair(254, 255)
+    con.clear()
+    graphics.clearPixels(255)
+    graphics.clearPixels2(255)
+    graphics.setFramebufferScroll(0, 0)
+    _fsh.drawWallpaper()
+    _fsh.drawTitlebar()
+    _fsh.widgets["com.fsh.clock"].draw(25, 3)
+    _fsh.widgets["com.fsh.calendar"].draw(12, 8)
+    _fsh.widgets["com.fsh.todo_list"].draw(10, 17)
+    _fsh.widgets["com.fsh.quick_access"].draw(47, 8)
+}
+
+_fsh.openAddTodoDialog = function() {
+    let res = win.showDialog({
+        title: "New Todo",
+        fields: [{label: "Text:", initial: "", width: _fsh.TODO_TEXT_WIDTH}],
+        allowDelete: false
+    })
+    _fsh.redrawAll()
+    if (res.action !== "ok") return
+    let text = res.values[0].trim()
+    if (text.length === 0) return
+    if (todoWidget.todoList.length >= _fsh.TODO_MAX_ROWS) return
+    todoWidget.todoList.push([text, false])
+    _fsh.saveConfig()
+}
+
+_fsh.openEditTodoDialog = function(index) {
+    let entry = todoWidget.todoList[index]
+    if (!entry) return
+    let res = win.showDialog({
+        title: "Edit Todo",
+        fields: [{label: "Text:", initial: entry[0], width: _fsh.TODO_TEXT_WIDTH}],
+        allowDelete: true
+    })
+    _fsh.redrawAll()
+    if (res.action === "cancel") return
+    if (res.action === "delete") {
+        todoWidget.todoList.splice(index, 1)
+        _fsh.saveConfig()
+        return
+    }
+    let text = res.values[0].trim()
+    if (text.length === 0) return
+    todoWidget.todoList[index] = [text, entry[1]]
+    _fsh.saveConfig()
+}
+
+_fsh.openAddQaDialog = function() {
+    let res = win.showDialog({
+        title: "New Quick Access",
+        fields: [
+            {label: "Label:",   initial: "", width: _fsh.QA_LABEL_WIDTH},
+            {label: "Command:", initial: "", width: _fsh.QA_CMD_WIDTH}
+        ],
+        allowDelete: false
+    })
+    _fsh.redrawAll()
+    if (res.action !== "ok") return
+    let label = res.values[0].trim()
+    let cmd = res.values[1].trim()
+    if (label.length === 0 || cmd.length === 0) return
+    if (quickAccessWidget.entries.length >= _fsh.QA_MAX_ROWS) return
+    quickAccessWidget.entries.push([label, cmd])
+    _fsh.saveConfig()
+}
+
+_fsh.openEditQaDialog = function(index) {
+    let entry = quickAccessWidget.entries[index]
+    if (!entry) return
+    let res = win.showDialog({
+        title: "Edit Quick Access",
+        fields: [
+            {label: "Label:",   initial: entry[0], width: _fsh.QA_LABEL_WIDTH},
+            {label: "Command:", initial: entry[1], width: _fsh.QA_CMD_WIDTH}
+        ],
+        allowDelete: true
+    })
+    _fsh.redrawAll()
+    if (res.action === "cancel") return
+    if (res.action === "delete") {
+        quickAccessWidget.entries.splice(index, 1)
+        _fsh.saveConfig()
+        return
+    }
+    let label = res.values[0].trim()
+    let cmd = res.values[1].trim()
+    if (label.length === 0 || cmd.length === 0) return
+    quickAccessWidget.entries[index] = [label, cmd]
+    _fsh.saveConfig()
+}
+
+_fsh.toggleTodoDone = function(index) {
+    let entry = todoWidget.todoList[index]
+    if (!entry) return
+    entry[1] = !entry[1]
+    _fsh.saveConfig()
+}
+
+// Launch a Quick Access entry. cmd is the verbatim string the user typed.
+// We split on first space to derive a program path + args; if the path
+// has no leading "/", we treat it as relative to the current drive.
+_fsh.launchEntry = function(label, cmd) {
+    let firstSpace = cmd.indexOf(" ")
+    let progPath = (firstSpace >= 0) ? cmd.substring(0, firstSpace) : cmd
+    let argTail = (firstSpace >= 0) ? cmd.substring(firstSpace + 1) : ""
+    let fullPath = progPath.startsWith("/") ? ("A:" + progPath) : progPath
+
+    try {
+        let f = files.open(fullPath)
+        if (!f.exists) {
+            serial.printerr("fsh.launchEntry: not found: " + fullPath)
+            return
+        }
+        let code = f.sread()
+        let tokens = [progPath].concat(argTail.length ? argTail.split(" ") : [])
+
+        // erase all pixels and draw wallpaper
+        con.reset_graphics()
+        con.clear()
+        graphics.clearPixels(255)
+        graphics.clearPixels2(255)
+        _fsh.drawWallpaper()
+        con.curs_set(1)
+
+        execApp(code, tokens)
+    } catch (e) {
+        serial.printerr("fsh.launchEntry: " + label + " failed: " + e)
+    }
+    con.curs_set(0)
+    graphics.setBackground(2,1,3)
+    graphics.resetPalette()
+    // Apps (e.g. zfm) may switch to graphics mode 0; restore mode 3 so the
+    // clock widget on framebuffer 2 is composited again.
+    graphics.setGraphicsMode(3)
+    _fsh.redrawAll()
+}
+
+// Layout map: widget positions hard-coded to match the draw calls below.
+_fsh.layouts = {
+    "com.fsh.todo_list":    {xoff: 10, yoff: 17, widget: null},
+    "com.fsh.quick_access": {xoff: 47, yoff: 8,  widget: null}
+}
+
+// Find which widget (if any) was hit by (charX, charY). Returns
+// {widgetId, hit} or null.
+_fsh.findHit = function(charX, charY) {
+    let ids = ["com.fsh.todo_list", "com.fsh.quick_access"]
+    for (let i = 0; i < ids.length; i++) {
+        let id = ids[i]
+        let layout = _fsh.layouts[id]
+        let widget = _fsh.widgets[id]
+        let hit = widget.hitTest(charX, charY, layout.xoff, layout.yoff)
+        if (hit) return {widgetId: id, hit: hit}
+    }
+    return null
+}
+
+_fsh.dispatchLeft = function(widgetId, hit) {
+    if (hit.kind === "add") {
+        if (widgetId === "com.fsh.todo_list") _fsh.openAddTodoDialog()
+        else                                  _fsh.openAddQaDialog()
+        return
+    }
+    // hit.kind === "item"
+    if (widgetId === "com.fsh.todo_list") {
+        _fsh.toggleTodoDone(hit.index)
+    } else {
+        let entry = quickAccessWidget.entries[hit.index]
+        if (entry) _fsh.launchEntry(entry[0], entry[1])
+    }
+}
+
+_fsh.dispatchRight = function(widgetId, hit) {
+    if (hit.kind !== "item") return
+    if (widgetId === "com.fsh.todo_list") _fsh.openEditTodoDialog(hit.index)
+    else                                  _fsh.openEditQaDialog(hit.index)
+}
+
 
 // change graphics mode and check if it's supported
 graphics.setGraphicsMode(3)
@@ -260,29 +631,130 @@ _fsh.drawWallpaper()
 _fsh.drawTitlebar()
 
 
-// TEST
-con.move(2,1);
-print("fSh is very much in-dev! Hit backspace to exit")
+// Load persisted state before the first draw
+_fsh.loadConfig();
+
+// keyEventBuffers (read via sys.peek(-41-i)) holds *raw libGDX keycodes*,
+// not the cooked TSVM scancodes that con.getch() returns. Existing fsh.js
+// already uses 67 for Backspace (libGDX DEL); follow the same scheme here.
+const KEY_ESC    = keysym.ESCAPE
+const KEY_ENTER  = keysym.ENTER
+const KEY_UP     = keysym.UP
+const KEY_DOWN   = keysym.DOWN
+const KEY_LEFT   = keysym.LEFT
+const KEY_RIGHT  = keysym.RIGHT
+const KEY_LSHIFT = keysym.SHIFT_LEFT
+const KEY_RSHIFT = keysym.SHIFT_RIGHT
+
+let prevButtons = 0
+let prevMouseCharX = -1
+let prevMouseCharY = -1
+let keyLatch = {}   // {keycode: true} while the key is held — debounces "just pressed"
 
-// TODO update for events: key down (updates some widgets), timer (updates clock and calendar widgets)
 while (true) {
-    captureUserInput();
-    if (getKeyPushed(0) == 67) break;
+    captureUserInput()
 
-    _fsh.widgets["com.fsh.clock"].draw(25, 3);
-    _fsh.widgets["com.fsh.calendar"].draw(12, 8);
-    _fsh.widgets["com.fsh.todo_list"].draw(10, 17);
-    _fsh.widgets["com.fsh.quick_access"].draw(47, 8);
+    // -- keyboard --
+    if (isKeyDown(KEY_ESC)) break;
 
-    sys.spin();sys.spin()
+    let shiftDown = isKeyDown(KEY_LSHIFT) || isKeyDown(KEY_RSHIFT)
+    let enterPressed = false
+
+    // Edge-detect each navigation key
+    function edge(kc) {
+        let down = isKeyDown(kc)
+        let was  = !!keyLatch[kc]
+        keyLatch[kc] = down
+        return down && !was
+    }
+
+    if (edge(KEY_ENTER)) enterPressed = true;
+    let navUp    = edge(KEY_UP)
+    let navDown  = edge(KEY_DOWN)
+    let navLeft  = edge(KEY_LEFT)
+    let navRight = edge(KEY_RIGHT)
+
+    // -- mouse --
+    // MMIO returns VM-screen pixel coords (origin at the top-left of the framebuffer).
+    // Widget xoff/yoff are passed straight into con.move(y, x), which is 1-indexed, so
+    // we offset by +1 here. Without this the click registers one cell up-and-left from
+    // where the user's pointer is, because pixel 0 = con.move(1, 1).
+    let pos = readMousePos()
+    let charX = (pos[0] / 7  | 0) + 1
+    let charY = (pos[1] / 14 | 0) + 1
+    let mouseMoved = (charX !== prevMouseCharX || charY !== prevMouseCharY)
+    prevMouseCharX = charX
+    prevMouseCharY = charY
+
+    let buttons = readMouseButtons()
+    let leftEdge  = ((buttons & _fsh.MB_LEFT)  !== 0) && ((prevButtons & _fsh.MB_LEFT)  === 0)
+    let rightEdge = ((buttons & _fsh.MB_RIGHT) !== 0) && ((prevButtons & _fsh.MB_RIGHT) === 0)
+    prevButtons = buttons
+
+    // -- focus update --
+    if (navUp || navDown || navLeft || navRight) {
+        if (!_fsh.focus) _fsh.focus = {widgetId: "com.fsh.todo_list", index: 0}
+        if (navUp || navDown) {
+            let layout = _fsh.layouts[_fsh.focus.widgetId]
+            let maxRows = (_fsh.focus.widgetId === "com.fsh.todo_list")
+                ? _fsh.TODO_MAX_ROWS : _fsh.QA_MAX_ROWS
+            let length = (_fsh.focus.widgetId === "com.fsh.todo_list")
+                ? todoWidget.todoList.length : quickAccessWidget.entries.length
+            let maxIdx = Math.min(length, maxRows - 1)
+            let next = _fsh.focus.index + (navDown ? 1 : -1)
+            if (next < 0) next = 0
+            if (next > maxIdx) next = maxIdx
+            _fsh.focus.index = next
+        } else {
+            // Left/right switches widget
+            let other = (_fsh.focus.widgetId === "com.fsh.todo_list")
+                ? "com.fsh.quick_access" : "com.fsh.todo_list"
+            let otherLength = (other === "com.fsh.todo_list")
+                ? todoWidget.todoList.length : quickAccessWidget.entries.length
+            let otherMaxRows = (other === "com.fsh.todo_list")
+                ? _fsh.TODO_MAX_ROWS : _fsh.QA_MAX_ROWS
+            let otherMaxIdx = Math.min(otherLength, otherMaxRows - 1)
+            _fsh.focus = {widgetId: other, index: Math.min(_fsh.focus.index, otherMaxIdx)}
+        }
+    } else if (mouseMoved) {
+        let h = _fsh.findHit(charX, charY)
+        _fsh.focus = h ? {widgetId: h.widgetId, index: h.hit.kind === "add"
+                            ? ((h.widgetId === "com.fsh.todo_list")
+                                ? todoWidget.todoList.length
+                                : quickAccessWidget.entries.length)
+                            : h.hit.index} : null
+    }
+
+    // -- mouse click dispatch --
+    if (leftEdge) {
+        let h = _fsh.findHit(charX, charY)
+        if (h) _fsh.dispatchLeft(h.widgetId, h.hit)
+    } else if (rightEdge) {
+        let h = _fsh.findHit(charX, charY)
+        if (h) _fsh.dispatchRight(h.widgetId, h.hit)
+    }
+
+    // -- keyboard dispatch (synthesise click at focus) --
+    if (enterPressed && _fsh.focus) {
+        let length = (_fsh.focus.widgetId === "com.fsh.todo_list")
+            ? todoWidget.todoList.length : quickAccessWidget.entries.length
+        let hit = (_fsh.focus.index < length)
+            ? {kind: "item", index: _fsh.focus.index}
+            : (_fsh.focus.index === length ? {kind: "add"} : null)
+        if (hit) {
+            if (shiftDown) _fsh.dispatchRight(_fsh.focus.widgetId, hit)
+            else           _fsh.dispatchLeft(_fsh.focus.widgetId, hit)
+        }
+    }
+
+    // -- redraw --
+    _fsh.widgets["com.fsh.clock"].draw(25, 3)
+    _fsh.widgets["com.fsh.calendar"].draw(12, 8)
+    _fsh.widgets["com.fsh.todo_list"].draw(10, 17)
+    _fsh.widgets["com.fsh.quick_access"].draw(47, 8)
+
+    sys.spin(); sys.spin()
 }
 
-con.move(3,1);
-con.color_pair(201,255);
-print("cya!");
-
-let konsht = 3412341241;
-println(konsht);
-
-let pppp = graphics.getCursorYX();
-println(pppp.toString());
+con.reset_graphics()
+con.clear()

assets/disk0/nettest.js

@@ -1,11 +1,13 @@
-let url="http:localhost/testnet/test.txt"
+/*let url="https:raw.githubusercontent.com/curioustorvald/hopper-mirror/refs/heads/master/aa.hop.per"
 
 let file = files.open("B:\\"+url)
 
 if (!file.exists) {
     printerrln("No such URL: "+url)
     return 1
-}
+}*/
 
-let text = file.sread()
+let net = require("A:/tvdos/include/net.mjs")
+let text = net.fetchText("https://raw.githubusercontent.com/curioustorvald/hopper-mirror/refs/heads/master/aa.hop.per")
+if (text === null) { printerrln("No such URL"); return 1 }
 println(text)

assets/disk0/tbas/basic.js

@@ -32,7 +32,7 @@ if (exec_args !== undefined && exec_args[1] !== undefined && exec_args[1].starts
     return 0
 }
 
-const THEVERSION = "1.2.1"
+const THEVERSION = "1.2.2"
 
 const PROD = true
 let INDEX_BASE = 0
@@ -4197,7 +4197,7 @@ bF.load = function(args) { // LOAD function
     if (args[1] === undefined) throw lang.missingOperand
     var fileOpened = fs.open(args[1], "R")
 
-
+    serial.printerr('load '+args[1])
     if (replUsrConfirmed || cmdbuf.length == 0) {
         if (!fileOpened) {
             fileOpened = fs.open(args[1]+".BAS", "R")
@@ -4241,7 +4241,7 @@ bF.yes = function() {
     }
 }
 bF.catalog = function(args) { // CATALOG function
-    if (args[1] === undefined) args[1] = "\\"
+    if (args[1] === undefined) args[1] = BASIC_HOME_PATH
     var pathOpened = fs.open(args[1], 'R')
     if (!pathOpened) {
         throw lang.noSuchFile
@@ -4251,6 +4251,57 @@ bF.catalog = function(args) { // CATALOG function
     com.sendMessage(port, "LIST")
     println(com.pullMessage(port))
 }
+// Load a file by absolute disk path (bypasses BASIC_HOME_PATH).
+// Used by COMPILE to fetch /tbas/compile.js.
+bF._slurpAbsolute = function(path) {
+    var port = _BIOS.FIRST_BOOTABLE_PORT
+    com.sendMessage(port[0], "FLUSH")
+    com.sendMessage(port[0], "CLOSE")
+    com.sendMessage(port[0], 'OPENR"' + path + '",' + port[1])
+    if (com.getStatusCode(port[0]) != 0) return undefined
+    com.sendMessage(port[0], "READ")
+    if (com.getStatusCode(port[0]) >= 128) return undefined
+    var s = com.pullMessage(port[0])
+    com.sendMessage(port[0], "FLUSH"); com.sendMessage(port[0], "CLOSE")
+    return s
+}
+bF.compile = function(args) { // COMPILE "OUT.JS" -- transpile cmdbuf to JS
+    if (args[1] === undefined) {
+        println("Usage: COMPILE \"out.js\""); return
+    }
+    if (cmdbuf.length === 0) {
+        println("No program loaded"); return
+    }
+    if (bS._compileImpl === undefined) {
+        // Lazy-load compile.js from /tbas/compile.js
+        var src = bF._slurpAbsolute("/tbas/compile.js")
+        if (src === undefined) {
+            println("Cannot load /tbas/compile.js")
+            return
+        }
+        try { eval(src) } catch (e) {
+            println("Failed to load compiler: " + e); return
+        }
+        if (bS._compileImpl === undefined) {
+            println("compile.js loaded but did not define bS._compileImpl"); return
+        }
+    }
+    var outpath = args[1]
+    // Strip surrounding quotes if any
+    if ((outpath.charAt(0) === '"' || outpath.charAt(0) === "'") &&
+        outpath.charAt(outpath.length - 1) === outpath.charAt(0)) {
+        outpath = outpath.substring(1, outpath.length - 1)
+    }
+    // Default to .js extension if missing
+    if (!/\.[A-Za-z0-9]+$/.test(outpath)) outpath += ".js"
+    try {
+        var n = bS._compileImpl(outpath)
+        println("Wrote " + n + " bytes to " + outpath)
+    } catch (e) {
+        serial.printerr(e + "\n" + (e.stack || ""))
+        println("Compile error: " + e)
+    }
+}
 Object.freeze(bF)
 
 if (exec_args !== undefined && exec_args[1] !== undefined) {

assets/disk0/tbas/compile.js

@@ -0,0 +1,564 @@
+// Terran BASIC -> JavaScript compiler
+// Loaded into basic.js's context by `bF.compile`. Re-uses bF._interpretLine
+// (tokeniser + elaborator + parser + pruner) verbatim and emits a self-
+// contained JS program that does its work via `let bS = require("tbas")`.
+//
+// On load, attaches `bS._compileImpl` to the live bS object.
+
+;(function() {
+
+// ---------- helpers ----------------------------------------------------------
+
+function isValidJsId(s) {
+    return /^[A-Z_][A-Z0-9_]*$/i.test(s)
+}
+function varRef(name) {
+    const u = String(name).toUpperCase()
+    return isValidJsId(u) ? `bS.__state.vars.${u}` : `bS.__state.vars[${JSON.stringify(u)}]`
+}
+function jsLit(v) { return JSON.stringify(v) }
+
+// Resolve a literal AST node down to a raw JS value at compile time. Used
+// for harvesting DATA constants. Only constant-propagatable types are
+// permitted; otherwise compile-time evaluation fails.
+function literalValue(node) {
+    if (!node) return undefined
+    switch (node.astType) {
+        case "num":    return Number(node.astValue)
+        case "string": return String(node.astValue)
+        case "bool":   return Boolean(node.astValue)
+        case "null":   return undefined
+        case "lit":    return String(node.astValue) // bare identifier in DATA: keep as string
+        default:
+            throw Error("DATA: unsupported literal node type: " + node.astType)
+    }
+}
+
+// Returns the maximum varIndex used at the immediate scope of a lambda body,
+// hence its arity.
+function lambdaArity(body) {
+    let maxIdx = -1
+    function walk(t, level) {
+        if (!t || !t.astType) return
+        if (t.astType === "defun_args" && t.astValue[0] === level) {
+            if (t.astValue[1] > maxIdx) maxIdx = t.astValue[1]
+        }
+        // descend into nested usrdefun (its body lives in astValue, not leaves)
+        if (t.astType === "usrdefun" && t.astValue && t.astValue.astLeaves !== undefined) {
+            walk(t.astValue, level + 1)
+        }
+        // generic descent
+        if (t.astLeaves) {
+            for (let i = 0; i < t.astLeaves.length; i++) walk(t.astLeaves[i], level)
+        }
+    }
+    walk(body, 0)
+    return maxIdx + 1
+}
+
+// ---------- expression lowering ---------------------------------------------
+
+// `depth` tracks the number of enclosing lambdas during emission. When we
+// emit a lambda we increment it; defun_args [d, i] becomes _aN_i where
+// N = depth - 1 - d  (the absolute lambda index of the binding scope).
+function compileExpr(tree, depth) {
+    if (tree === undefined || tree === null) return "undefined"
+
+    // Empty parens / wrapper node: descend into the single child
+    if (tree.astType === "null") {
+        if (tree.astLeaves && tree.astLeaves[0] !== undefined) return compileExpr(tree.astLeaves[0], depth)
+        return "undefined"
+    }
+    if (tree.astValue === undefined && tree.astLeaves && tree.astLeaves.length === 1) {
+        return compileExpr(tree.astLeaves[0], depth)
+    }
+
+    switch (tree.astType) {
+        case "num":    return String(Number(tree.astValue))
+        case "string": return jsLit(String(tree.astValue))
+        case "bool":   return tree.astValue ? "true" : "false"
+        case "lit":    return compileLit(tree)
+        case "defun_args": {
+            const d = tree.astValue[0], i = tree.astValue[1]
+            const scope = depth - 1 - d
+            if (scope < 0) throw Error("defun_args refers to a scope outside the program (depth=" + depth + ", d=" + d + ")")
+            return "_a" + scope + "_" + i
+        }
+        case "usrdefun": return compileLambdaExpr(tree, depth)
+        case "array":    return compileArrayRef(tree, depth)
+        case "function": return compileFunctionExpr(tree, depth)
+        case "op":       return compileOpExpr(tree, depth)
+        default:
+            throw Error("Cannot compile expression node of type: " + tree.astType + " (value=" + tree.astValue + ")")
+    }
+}
+
+function compileLit(tree) {
+    const name = String(tree.astValue).toUpperCase()
+    // Built-in zero-arg / pass-as-value functions: when a builtin name is
+    // referenced as a value (e.g. assigned to a variable for later use as a
+    // higher-order arg), emit a JS function reference. For a plain variable
+    // read, emit the vars table lookup.
+    // Heuristic: if the name matches a builtin we know about, prefer the
+    // function; otherwise, vars lookup.
+    if (RUNTIME_BUILTINS.has(name)) {
+        return "bS." + (isValidJsId(name) ? name : `[${jsLit(name)}]`)
+    }
+    return varRef(name)
+}
+
+function compileArrayRef(tree, depth) {
+    // tree.astValue = array variable name; tree.astLeaves = index expressions
+    if (!tree.astLeaves || tree.astLeaves.length === 0) {
+        return varRef(tree.astValue)
+    }
+    const indices = tree.astLeaves.map(l => compileExpr(l, depth))
+    return `bS.__arrGet(${varRef(tree.astValue)}, [${indices.join(",")}])`
+}
+
+function compileFunctionExpr(tree, depth) {
+    const name = String(tree.astValue).toUpperCase()
+
+    if (name === "PRINT" || name === "EMIT") {
+        // PRINT/EMIT used as expression — emit as IIFE returning undefined
+        return "(" + compilePrintLike(tree, name, depth) + ", undefined)"
+    }
+    // user function call by name: <varname>(args)  — when astType is "function"
+    // and astValue is a string that matches a variable, the parser may have
+    // generated this. Treat it as: invoke the var.
+    if (!RUNTIME_BUILTINS.has(name)) {
+        // Not a known builtin: treat as a user defined function call
+        const args = (tree.astLeaves || []).map(l => compileExpr(l, depth))
+        return `bS.__runFn(${varRef(name)}, [${args.join(",")}])`
+    }
+
+    const args = (tree.astLeaves || []).map(l => compileExpr(l, depth))
+    return `bS.${isValidJsId(name) ? name : `[${jsLit(name)}]`}(${args.join(",")})`
+}
+
+const ARITH_OP = {
+    "+":  (l,r) => `bS.__add(${l},${r})`,
+    "-":  (l,r) => `((${l})-(${r}))`,
+    "*":  (l,r) => `((${l})*(${r}))`,
+    "/":  (l,r) => `bS.__div(${l},${r})`,
+    "\\": (l,r) => `bS.__intdiv(${l},${r})`,
+    "MOD":(l,r) => `bS.__mod(${l},${r})`,
+    "^":  (l,r) => `bS.__pow(${l},${r})`,
+    "==": (l,r) => `((${l})==(${r}))`,
+    "<>": (l,r) => `((${l})!=(${r}))`,
+    "><": (l,r) => `((${l})!=(${r}))`,
+    "<":  (l,r) => `((${l})<(${r}))`,
+    ">":  (l,r) => `((${l})>(${r}))`,
+    "<=": (l,r) => `((${l})<=(${r}))`,
+    "=<": (l,r) => `((${l})<=(${r}))`,
+    ">=": (l,r) => `((${l})>=(${r}))`,
+    "=>": (l,r) => `((${l})>=(${r}))`,
+    "AND":(l,r) => `bS.AND(${l},${r})`,
+    "OR": (l,r) => `bS.OR(${l},${r})`,
+    "<<": (l,r) => `((${l})<<(${r}))`,
+    ">>": (l,r) => `((${l})>>>(${r}))`,
+    "BAND":(l,r) => `((${l})&(${r}))`,
+    "BOR": (l,r) => `((${l})|(${r}))`,
+    "BXOR":(l,r) => `((${l})^(${r}))`,
+}
+const UNARY_OP = {
+    "UNARYMINUS":   (a) => `(-(${a}))`,
+    "UNARYPLUS":    (a) => `(+(${a}))`,
+    "UNARYLOGICNOT":(a) => `(!(${a}))`,
+    "UNARYBNOT":    (a) => `(~(${a}))`,
+}
+
+function compileOpExpr(tree, depth) {
+    const op = String(tree.astValue)
+    const leaves = tree.astLeaves || []
+
+    // Unary
+    if (UNARY_OP[op] && (leaves.length === 1 || leaves[1] === undefined)) {
+        return UNARY_OP[op](compileExpr(leaves[0], depth))
+    }
+
+    // Binary arithmetic / comparison / logic
+    if (ARITH_OP[op] && leaves.length === 2) {
+        return ARITH_OP[op](compileExpr(leaves[0], depth), compileExpr(leaves[1], depth))
+    }
+
+    // Generator / range
+    if (op === "TO" && leaves.length === 2) {
+        return `new bS.__ForGen(${compileExpr(leaves[0], depth)}, ${compileExpr(leaves[1], depth)}, 1)`
+    }
+    if (op === "STEP" && leaves.length === 2) {
+        return `bS.STEP(${compileExpr(leaves[0], depth)}, ${compileExpr(leaves[1], depth)})`
+    }
+
+    // List ops
+    if ((op === "!" || op === "~" || op === "#") && leaves.length === 2) {
+        const fn = (op === "!") ? "['!']" : (op === "~") ? "['~']" : "['#']"
+        return `bS${fn}(${compileExpr(leaves[0], depth)}, ${compileExpr(leaves[1], depth)})`
+    }
+
+    // Assignment as expression — returns the assigned value
+    if (op === "=" && leaves.length === 2) {
+        return "(" + compileAssignExpr(tree, depth) + ")"
+    }
+    if (op === "IN" && leaves.length === 2) {
+        // Used inside FOR/FOREACH; compileFor unwraps these. As a value, treat
+        // as { asgnVarName, asgnValue } so a stray IN still works.
+        const name = jsLit(String(leaves[0].astValue).toUpperCase())
+        const rhs = compileExpr(leaves[1], depth)
+        return `({asgnVarName: ${name}, asgnValue: ${rhs}})`
+    }
+
+    // Functional / monad ops
+    if ((op === ">>=" || op === ">>~" || op === "." || op === "$" ||
+         op === "&"   || op === "~<"  || op === "<*>" || op === "<$>" ||
+         op === "<~>") && leaves.length === 2) {
+        return `bS[${jsLit(op)}](${compileExpr(leaves[0], depth)}, ${compileExpr(leaves[1], depth)})`
+    }
+    if (op === "@" && leaves.length === 1) {
+        // Monad return as prefix
+        return `bS.MRET(${compileExpr(leaves[0], depth)})`
+    }
+    if (op === "~>") {
+        throw Error("Compiler: bare ~> survived prune (should be usrdefun)")
+    }
+
+    throw Error("Cannot compile op '" + op + "' with " + leaves.length + " operand(s)")
+}
+
+function compileLambdaExpr(tree, depth) {
+    // tree.astType === "usrdefun"; tree.astValue holds the body AST; if
+    // tree.astLeaves is non-empty, this is an immediate application.
+    const body = tree.astValue
+    if (!body || !body.astType) throw Error("Malformed usrdefun")
+
+    const arity = lambdaArity(body)
+    const newDepth = depth + 1
+    const params = []
+    for (let i = 0; i < arity; i++) params.push("_a" + (newDepth - 1) + "_" + i)
+    const bodyJs = compileExpr(body, newDepth)
+    const arrow = `((${params.join(",")}) => (${bodyJs}))`
+
+    if (tree.astLeaves && tree.astLeaves.length > 0) {
+        const args = tree.astLeaves.map(l => compileExpr(l, depth))
+        return `${arrow}(${args.join(",")})`
+    }
+    return arrow
+}
+
+function compileAssignExpr(tree, depth) {
+    // op "=" with leaves[0] as target, leaves[1] as RHS
+    const lhs = tree.astLeaves[0]
+    const rhs = compileExpr(tree.astLeaves[1], depth)
+
+    if (lhs.astType === "lit") {
+        const name = String(lhs.astValue).toUpperCase()
+        return `(${varRef(name)} = ${rhs})`
+    }
+    // The parser emits "function" or "array" for `A(i,j) = ...` — both mean
+    // "store into element of A".
+    if (lhs.astType === "array" || lhs.astType === "function") {
+        const indices = lhs.astLeaves.map(l => compileExpr(l, depth))
+        return `(bS.__arrSet(${varRef(lhs.astValue)}, [${indices.join(",")}], ${rhs}), ${rhs})`
+    }
+    throw Error("Cannot assign to LHS of type " + lhs.astType)
+}
+
+// ---------- statement lowering ----------------------------------------------
+
+function compilePrintLike(tree, fname, depth) {
+    const leaves = (tree.astLeaves || []).slice()
+    const seps = (tree.astSeps || []).slice()
+
+    let suppressNewline = false
+    if (leaves.length > 0 && leaves[leaves.length - 1] !== undefined &&
+        leaves[leaves.length - 1].astType === "null") {
+        suppressNewline = true
+        leaves.pop()
+    }
+
+    const valueExprs = leaves.map(l => compileExpr(l, depth))
+    if (suppressNewline) valueExprs.push("bS.__PRINT_NONL")
+    const sepArr = seps.slice(0, leaves.length - 1)
+
+    return `bS.${fname}([${valueExprs.join(", ")}], ${jsLit(sepArr)})`
+}
+
+function setPc(pc) {
+    if (pc[0] === Infinity) return "pc=[Infinity,0];"
+    return "pc=[" + pc[0] + "," + pc[1] + "];"
+}
+
+function compileStatement(tree, lnum, stmt, nextPc) {
+    if (!tree) return setPc(nextPc)
+    if (tree.astType === "null" && tree.astLeaves && tree.astLeaves[0]) {
+        return compileStatement(tree.astLeaves[0], lnum, stmt, nextPc)
+    }
+
+    const isFn = (tree.astType === "function" || tree.astType === "op")
+    const fname = isFn ? String(tree.astValue).toUpperCase() : null
+
+    switch (fname) {
+    case "GOTO": {
+        const target = compileGotoTarget(tree.astLeaves[0])
+        return `pc=${target};`
+    }
+    case "GOSUB": {
+        const target = compileGotoTarget(tree.astLeaves[0])
+        return `gosubStack.push([${nextPc[0]},${nextPc[1]}]); pc=${target};`
+    }
+    case "RETURN":
+        return `pc=gosubStack.pop(); if(!pc) throw new Error("RETURN without GOSUB");`
+    case "END":
+        return "pc=[Infinity,0];"
+    case "IF":
+        return compileIf(tree, lnum, stmt, nextPc)
+    case "ON":
+        return compileOn(tree, lnum, stmt, nextPc)
+    case "FOR":
+    case "FOREACH":
+        return compileFor(tree, lnum, stmt, nextPc, fname === "FOREACH")
+    case "NEXT":
+        return compileNext(tree, lnum, stmt, nextPc)
+    case "READ": {
+        const target = tree.astLeaves[0]
+        if (target.astType !== "lit") throw Error("READ: target must be a variable")
+        return `${varRef(target.astValue)}=bS.__readData(); ${setPc(nextPc)}`
+    }
+    case "RESTORE":
+        return `bS.__state.dataCursor=0; ${setPc(nextPc)}`
+    case "DATA":
+    case "LABEL":
+        return setPc(nextPc) // harvested at compile time
+    case "DIM":
+        return compileDim(tree, lnum, stmt, nextPc)
+    case "PRINT":
+    case "EMIT":
+        return `${compilePrintLike(tree, fname, 0)}; ${setPc(nextPc)}`
+    case "OPTIONBASE":
+        return `bS.OPTIONBASE(${compileExpr(tree.astLeaves[0], 0)}); ${setPc(nextPc)}`
+    case "OPTIONDEBUG":
+        return `bS.OPTIONDEBUG(${compileExpr(tree.astLeaves[0], 0)}); ${setPc(nextPc)}`
+    case "OPTIONTRACE":
+        return `bS.OPTIONTRACE(${compileExpr(tree.astLeaves[0], 0)}); ${setPc(nextPc)}`
+    case "INPUT": {
+        // INPUT <var> -> read into var
+        const target = tree.astLeaves[tree.astLeaves.length - 1]
+        if (target.astType !== "lit") throw Error("INPUT: target must be a variable")
+        return `${varRef(target.astValue)}=bS.INPUT(); ${setPc(nextPc)}`
+    }
+    case "=":
+        return `${compileAssignExpr(tree, 0)}; ${setPc(nextPc)}`
+    case "IN":
+        // bare IN as a statement is unusual but harmless
+        return `${compileExpr(tree, 0)}; ${setPc(nextPc)}`
+    case "REM":
+        return setPc(nextPc)
+    }
+
+    // Default: evaluate as an expression for side effect, then advance
+    return `${compileExpr(tree, 0)}; ${setPc(nextPc)}`
+}
+
+function compileGotoTarget(leaf) {
+    // Always route through __resolveTarget so non-existent line numbers snap
+    // upward to the next existing line — matching basic.js's main loop,
+    // which increments lnum until it finds a populated cmdbuf entry.
+    if (leaf.astType === "num") return `bS.__resolveTarget(${Number(leaf.astValue)})`
+    if (leaf.astType === "string") return `bS.__resolveTarget(${jsLit(leaf.astValue)})`
+    if (leaf.astType === "lit") {
+        const name = String(leaf.astValue)
+        return `bS.__resolveTarget(bS.__state.gotoLabels[${jsLit(name)}]!==undefined ? ${jsLit(name)} : ${varRef(name)})`
+    }
+    return `bS.__resolveTarget(${compileExpr(leaf, 0)})`
+}
+
+function compileIf(tree, lnum, stmt, nextPc) {
+    const test = compileExpr(tree.astLeaves[0], 0)
+    const thenStmt = compileStatement(tree.astLeaves[1], lnum, stmt, nextPc)
+    const elseStmt = (tree.astLeaves[2])
+        ? compileStatement(tree.astLeaves[2], lnum, stmt, nextPc)
+        : setPc(nextPc)
+    return `if(bS.__test(${test})){${thenStmt}}else{${elseStmt}}`
+}
+
+function compileOn(tree, lnum, stmt, nextPc) {
+    // children: testExpr, jumpFnLit, target0, target1, ...
+    const testExpr = compileExpr(tree.astLeaves[0], 0)
+    const jmpFn    = String(tree.astLeaves[1].astValue).toUpperCase()
+    const targets  = tree.astLeaves.slice(2)
+
+    const cases = targets.map((t, i) => {
+        const tgt = compileGotoTarget(t)
+        if (jmpFn === "GOSUB") {
+            return `case ${i}: gosubStack.push([${nextPc[0]},${nextPc[1]}]); pc=${tgt}; break;`
+        }
+        return `case ${i}: pc=${tgt}; break;`
+    })
+    return `{const _o=(${testExpr})-bS.__state.indexBase; switch(_o){${cases.join(" ")} default: ${setPc(nextPc)}}}`
+}
+
+function compileFor(tree, lnum, stmt, nextPc, isForEach) {
+    const child = tree.astLeaves[0]
+    if (child.astType !== "op" || (child.astValue !== "=" && child.astValue !== "IN")) {
+        throw Error("FOR/FOREACH: expected = or IN, got " + child.astType + ":" + child.astValue)
+    }
+    const varname = String(child.astLeaves[0].astValue).toUpperCase()
+    let iter = compileExpr(child.astLeaves[1], 0)
+    if (isForEach) {
+        // ensure we coerce generators into arrays for FOREACH semantics
+        iter = `(function(_x){return bS.__isGenerator(_x)?bS.__genToArray(_x):_x})(${iter})`
+    }
+    // Pass nextPc — the PC of the loop body's first statement — so NEXT can
+    // jump straight back without relying on fall-through.
+    return `bS.__forSetup(${jsLit(varname)}, ${iter}, ${nextPc[0]}, ${nextPc[1]}); ${setPc(nextPc)}`
+}
+
+function compileNext(tree, lnum, stmt, nextPc) {
+    let argExpr = "undefined"
+    const leaves = tree.astLeaves || []
+    if (leaves.length === 1 && leaves[0] && leaves[0].astType === "lit") {
+        argExpr = jsLit(String(leaves[0].astValue).toUpperCase())
+    }
+    return `{const _n=bS.__forNext(${argExpr}); if(_n){pc=_n;}else{${setPc(nextPc)}}}`
+}
+
+function compileDim(tree, lnum, stmt, nextPc) {
+    // tree.astLeaves contains array constructor calls: each leaf is either
+    //   an `array` node OR a `function` node (the parser doesn't distinguish
+    //   `A(5)` from a function call until runtime). astValue is the variable
+    //   name and astLeaves are the dimension expressions.
+    const stmts = []
+    for (let i = 0; i < tree.astLeaves.length; i++) {
+        const leaf = tree.astLeaves[i]
+        if (leaf.astType !== "array" && leaf.astType !== "function") {
+            throw Error("DIM: expected array decl, got " + leaf.astType)
+        }
+        const name = String(leaf.astValue).toUpperCase()
+        const dims = leaf.astLeaves.map(l => compileExpr(l, 0))
+        stmts.push(`${varRef(name)}=bS.__dim([${dims.join(",")}]);`)
+    }
+    return stmts.join(" ") + " " + setPc(nextPc)
+}
+
+// ---------- top-level entry --------------------------------------------------
+
+// Set of builtin names exposed by tbas.mjs. Used to decide whether a `lit`
+// in expression position is a variable or a function reference.
+const RUNTIME_BUILTINS = new Set([
+    "PRINT","EMIT","INPUT","CIN",
+    "ABS","SGN","INT","FLOOR","CEIL","FIX","ROUND","SQR","CBR",
+    "SIN","COS","TAN","ASN","ACO","ATN","SINH","COSH","TANH",
+    "EXP","LOG","MIN","MAX","RND",
+    "SPC","LEFT","RIGHT","MID","CHR",
+    "LEN","HEAD","TAIL","INIT","LAST","MAP","FOLD","FILTER","ARRAY",
+    "CLS","CLPX","PLOT","GOTOYX","TEXTFORE","TEXTBACK",
+    "POKE","PEEK","GETKEYSDOWN","CPUT","CGET","CSTA",
+    "TYPEOF","OPTIONBASE","OPTIONDEBUG","OPTIONTRACE",
+    "MRET","MLIST","MJOIN",
+    "AND","OR","NOT",
+    "DO","CLEAR","END","TO","STEP",
+    "FOR","FOREACH","NEXT","IF","ON","GOTO","GOSUB","RETURN",
+    "DIM","DATA","READ","RESTORE","LABEL","REM",
+    "TEST",
+])
+
+bS._compileImpl = function(outpath) {
+    if (typeof cmdbuf === "undefined") throw Error("compile.js: cmdbuf not available")
+    if (typeof bF === "undefined")     throw Error("compile.js: bF not available")
+    if (typeof bF._interpretLine !== "function") throw Error("compile.js: bF._interpretLine not available")
+
+    // Reset parser-side state so we don't pollute the live interpreter
+    if (typeof lambdaBoundVars !== "undefined") lambdaBoundVars.length = 0
+    const savedPrescan = (typeof prescan !== "undefined") ? prescan : false
+    if (typeof prescan !== "undefined") prescan = true   // suppress execution of LABEL/DATA prescan side-effects
+
+    // ---- pass 1: parse every line ----
+    const programTrees = []   // [lnum] -> array of statements
+    for (let lnum = 0; lnum < cmdbuf.length; lnum++) {
+        const linestr = cmdbuf[lnum]
+        if (linestr === undefined) continue
+        const trees = bF._interpretLine(lnum, String(linestr).trim())
+        if (trees !== undefined) programTrees[lnum] = trees
+    }
+    if (typeof prescan !== "undefined") prescan = savedPrescan
+
+    // ---- pass 2: ordered list of populated lnums and successor table ----
+    const linenums = []
+    for (let lnum = 0; lnum < programTrees.length; lnum++) {
+        if (programTrees[lnum] !== undefined) linenums.push(lnum)
+    }
+
+    function nextPcOf(idx, stmtIdx) {
+        const lnum = linenums[idx]
+        const stmts = programTrees[lnum]
+        if (stmtIdx + 1 < stmts.length) return [lnum, stmtIdx + 1]
+        if (idx + 1 < linenums.length)  return [linenums[idx + 1], 0]
+        return [Infinity, 0]
+    }
+
+    // ---- pass 3: harvest DATA constants and LABEL definitions ----
+    const dataConsts = []
+    const labelMap = {}
+    for (let i = 0; i < linenums.length; i++) {
+        const lnum = linenums[i]
+        const stmts = programTrees[lnum]
+        for (let s = 0; s < stmts.length; s++) {
+            const t = stmts[s]
+            if (!t) continue
+            if (t.astValue === "DATA") {
+                for (let k = 0; k < t.astLeaves.length; k++) {
+                    dataConsts.push(literalValue(t.astLeaves[k]))
+                }
+            } else if (t.astValue === "LABEL") {
+                const lblNode = t.astLeaves[0]
+                if (!lblNode) throw Error("LABEL with no name on line " + lnum)
+                const lblName = String(lblNode.astValue)
+                labelMap[lblName] = [lnum, s]
+            }
+        }
+    }
+
+    // ---- pass 4: emit case bodies ----
+    const cases = []
+    for (let i = 0; i < linenums.length; i++) {
+        const lnum = linenums[i]
+        const stmts = programTrees[lnum]
+        for (let s = 0; s < stmts.length; s++) {
+            const next = nextPcOf(i, s)
+            const body = compileStatement(stmts[s], lnum, s, next)
+            cases.push(`    case ${lnum}*32+${s}: { ${body} break; }`)
+        }
+    }
+
+    // ---- pass 5: assemble final output ----
+    const firstPc = (linenums.length > 0) ? `[${linenums[0]},0]` : `[Infinity,0]`
+    const labelMapJs = "{" + Object.keys(labelMap).map(k =>
+        `${jsLit(k)}: [${labelMap[k][0]}, ${labelMap[k][1]}]`
+    ).join(", ") + "}"
+
+    const out =
+`// Compiled by Terran BASIC -> JS compiler (assets/disk0/tbas/compile.js)
+// Source line count: ${linenums.length}
+let bS = require("tbas")
+bS.__reset()
+bS.__data(${jsLit(dataConsts)})
+bS.__labels(${labelMapJs})
+bS.__setLines(${jsLit(linenums)})
+let pc = ${firstPc}
+const gosubStack = []
+while (pc[0] !== Infinity) {
+  switch (pc[0]*32 + pc[1]) {
+${cases.join("\n")}
+    default: pc = [Infinity, 0]; break;
+  }
+}
+`
+
+    // ---- write to disk via basic.js's fs (writes under BASIC_HOME_PATH) ----
+    const opened = fs.open(outpath, "W")
+    if (!opened) throw Error("Cannot open " + outpath + " for writing")
+    fs.write(out)
+    return out.length
+}
+
+})();

assets/disk0/tracker_test.js

@@ -19,9 +19,9 @@ var Note = (function() {
             if (flats[s] !== names[s]) t[flats[s] + oct] = n(oct, s);
         }
     }
-    t.OFF = 0x0000;   // key-off
-    t.CUT = 0xFFFE;   // note cut (immediate)
-    t.NOP = 0xFFFF;   // no-op (empty row)
+    t.NOP = 0x0000;   // no-op (empty row)
+    t.OFF = 0x0001;   // key-off
+    t.CUT = 0x0002;   // note cut (immediate)
     return t;
 }());
 

assets/disk0/tvdos/TVDOS.SYS

@@ -55,10 +55,12 @@ class PmemFSfile {
         // string representation (preferable)
         if (typeof bytes === 'string' || bytes instanceof String) {
             this.data = bytes
+            this.length = bytes.length
         }
         // Javascript array OR JVM byte[]
         else if (Array.isArray(bytes) || bytes.toString().startsWith("[B")) {
-            this.bdata = bytes[i]
+            this.bdata = bytes
+            this.length = bytes.length
         }
         else {
             throw Error("Invalid type for directory")
@@ -76,10 +78,10 @@ class PmemFSfile {
 
     dataAsBytes() {
         if (this.bdata !== undefined) return this.bdata
-        this.bdata = new Int8Array(this.data.length)
+        this.bdata = new Uint8Array(this.data.length)
         for (let i = 0; i < this.data.length; i++) {
             let p = this.data.charCodeAt(i)
-            this.bdata[i] = (p > 127) ? p - 255 : p
+            this.bdata[i] = p
         }
         return this.bdata
     }
@@ -147,10 +149,12 @@ _TVDOS.variables = {
     LANG: "EN",
     KEYBOARD: "us_qwerty",
     PATH: "\\tvdos\\bin;\\home",
+    INCLPATH: "\\tvdos\\include;\\home",
     PATHEXT: ".com;.bat;.app;.js;.alias",
     HELPPATH: "\\tvdos\\help",
     OS_NAME: "TSVM Disk Operating System",
-    OS_VERSION: _TVDOS.VERSION
+    OS_VERSION: _TVDOS.VERSION,
+    USERCONFIGPATH: "\\home\\config",
 };
 Object.freeze(_TVDOS);
 
@@ -162,16 +166,16 @@ class TVDOSFileDescriptor {
 
     constructor(path0, driverID) {
         if (path0.startsWith("$")) {
-            let path1 = path0.substring(3)
-            let slashPos = path1.indexOf("/")
+            let path1 = path0.replaceAll("/", "\\").substring(3)
+            let slashPos = path1.indexOf("\\")
             let devName = path1.substring(0, (slashPos < 0) ? path1.length : slashPos)
 
             if (!files.reservedNames.includes(devName)) {
                 throw Error(`${devName} is not a valid device file`)
             }
 
-            this._driveLetter = undefined
-            this._path = path0
+            this._driveLetter = '$'
+            this._path = '\\' + path1
             this._driverID = `DEV${devName}`
             this._driver = _TVDOS.DRV.FS[`DEV${devName}`] // can't just put `driverID` here
         }
@@ -937,8 +941,9 @@ _TVDOS.DRV.FS.DEVTMP.bread = (fd) => {
 _TVDOS.DRV.FS.DEVTMP.pread = (fd, ptr, count, offset) => {
     if (_TVDOS.TMPFS[fd.path] === undefined) throw Error(`No such file: ${fd.fullPath}`)
     let str = _TVDOS.TMPFS[fd.path].dataAsString()
-    for (let i = 0; i < count - (offset || 0); i++) {
-        sys.poke(ptr + i, String.charCodeAt(i + (offset || 0)))
+    let off = offset || 0
+    for (let i = 0; i < count; i++) {
+        sys.poke(ptr + i, str.charCodeAt(off + i))
     }
 }
 
@@ -986,6 +991,7 @@ _TVDOS.DRV.FS.DEVTMP.remove = (fd) => {
     return true
 }
 _TVDOS.DRV.FS.DEVTMP.exists = (fd) => (_TVDOS.TMPFS[fd.path] !== undefined)
+_TVDOS.DRV.FS.DEVTMP.getFileLen = (fd) => (_TVDOS.TMPFS[fd.path].length)
 
 Object.freeze(_TVDOS.DRV.FS.DEVTMP)
 
@@ -1108,13 +1114,18 @@ inputwork.repeatCount = 0;
  * where:
  *  "key_down", <key symbol string>, <repeat count>, keycode0, keycode1 .. keycode7
  *  "key_change", <key symbol string (what went up)>, 0, keycode0, keycode1 .. keycode7 (remaining keys that are held down)
- *  "mouse_down", pos-x, pos-y, 1 // yes there's only one mouse button :p
- *  "mouse_up", pos-x, pos-y, 0
- *  "mouse_move", pos-x, pos-y, <button down?>, oldpos-x, oldpos-y
+ *  "mouse_down",  pos-x, pos-y, <button mask: 1=left, 2=right, 4=middle>, keycode0..keycode7
+ *  "mouse_up",    pos-x, pos-y, <button mask of the released button>,    keycode0..keycode7
+ *  "mouse_move",  pos-x, pos-y, <currently-held button mask>, oldpos-x, oldpos-y, keycode0..keycode7
+ *  "mouse_wheel", pos-x, pos-y, <-1 for wheel up, +1 for wheel down>,     keycode0..keycode7
+ *
+ * Button mask values come from MMIO[36] bits 0..2 (terranmon.txt:52-58). The wheel
+ * bits (6, 7) latch in hardware and clear on read, so a one-shot detent fires once.
+ * Every mouse event carries the currently-held key buffer (same shape as key_down)
+ * so handlers can detect modifiers like Shift+wheel via `event.includes(<keysym>)`.
  */
 input.withEvent = function(callback) {
 
-    // TODO mouse event
     function arrayEq(a,b) {
         for (let i = 0; i < a.length; ++i) {
             if (a[i] !== b[i]) return false;
@@ -1135,7 +1146,33 @@ input.withEvent = function(callback) {
 
     sys.poke(-40, 255);
     let keys = [sys.peek(-41),sys.peek(-42),sys.peek(-43),sys.peek(-44),sys.peek(-45),sys.peek(-46),sys.peek(-47),sys.peek(-48)];
-    let mouse = [sys.peek(-33) | (sys.peek(-34) << 8), sys.peek(-35) | (sys.peek(-36) << 8), sys.peek(-37)];
+    let mx = (sys.peek(-33) & 0xFF) | ((sys.peek(-34) & 0xFF) << 8);
+    let my = (sys.peek(-35) & 0xFF) | ((sys.peek(-36) & 0xFF) << 8);
+    let mb = sys.peek(-37) & 0xFF; // bits 0..2 = L/R/M held, bit 6 = wheel up, bit 7 = wheel down
+    let mouse = [mx, my, mb];
+
+    // --- mouse dispatch ---
+    let oldMouse = inputwork.oldMouse;
+    let hasOld   = oldMouse && oldMouse.length === 3;
+    let oldBtns  = hasOld ? (oldMouse[2] & 0x07) : 0;
+    let curBtns  = mb & 0x07;
+    let wheelUp  = (mb & 0x40) !== 0;
+    let wheelDn  = (mb & 0x80) !== 0;
+
+    if (wheelUp) callback(["mouse_wheel", mx, my, -1].concat(keys));
+    if (wheelDn) callback(["mouse_wheel", mx, my,  1].concat(keys));
+
+    let pressed  = curBtns & ~oldBtns;
+    let released = oldBtns & ~curBtns;
+    for (let b = 1; b <= 4; b <<= 1) {
+        if (pressed  & b) callback(["mouse_down", mx, my, b].concat(keys));
+        if (released & b) callback(["mouse_up",   mx, my, b].concat(keys));
+    }
+    if (hasOld && (mx !== oldMouse[0] || my !== oldMouse[1])) {
+        callback(["mouse_move", mx, my, curBtns, oldMouse[0], oldMouse[1]].concat(keys));
+    }
+    // --- end mouse dispatch ---
+
     let keyChanged = !arrayEq(keys, inputwork.oldKeys)
     let keyDiff = arrayDiff(keys, inputwork.oldKeys)
 
@@ -1405,9 +1442,6 @@ let requireFromMemory = (ptr) => {
 }*/
 
 
-var GL = require("A:/tvdos/include/gl.mjs")
-
-
 // @param cmdsrc JS source code
 // @param args arguments for the program, must be Array, and args[0] is always the name of the program, e.g.
 //        for command line 'echo foo bar', args[0] must be 'echo'
@@ -1420,7 +1454,7 @@ var execApp = (cmdsrc, args, appname) => {
 `var ${appname}=function(exec_args){${injectIntChk(cmdsrc, intchkFunName)}\n};` +
 `${appname}`); // making 'exec_args' a app-level global
 
-        execAppPrg(args);
+        return execAppPrg(args);
 }
 
 
@@ -1437,9 +1471,40 @@ try {
     serial.println("Warning: Could not load HSDPA driver: " + e.message)
 }
 
-// Boot script
-serial.println(`TVDOS.SYS initialised on VM ${sys.getVmId()}, running boot script...`);
+// Boot script. The work is split across two files:
+//   \commandrc    -- environment (`set` commands); run in EVERY context.
+//   \AUTOEXEC.BAT -- per-console launch (IME + interactive shell).
+// vtmgr re-evaluates TVDOS.SYS inside each per-VT pane; a pane sets
+// _TVDOS_IS_VT_PANE so it only replays the environment here and leaves the
+// AUTOEXEC launch to vtmgr's pane bootstrap (which avoids recursively
+// spawning vtmgr inside a pane).
+{
+    let cmdsrc = files.open("A:/tvdos/bin/command.js").sread()
+    let runBatch = (path) => eval(`var _BAT=function(exec_args){${cmdsrc}\n};_BAT`)(["", "-c", path])
 
-let cmdfile = files.open("A:/tvdos/bin/command.js")
-eval(`var _AUTOEXEC=function(exec_args){${cmdfile.sread()}\n};` +
-      `_AUTOEXEC`)(["", "-c", "\\AUTOEXEC.BAT"])
+    // Environment first, boot and pane alike. Gives every pane the same
+    // PATH / KEYBOARD / etc. natively, with no env-snapshot replay needed.
+    // \commandrc has no .BAT extension (so command.js's batch-file path,
+    // which keys off the extension, won't pick it up); run it line-by-line.
+    // `set` mutates the shared _TVDOS.variables, so the effect persists across
+    // the per-line shell invocations. Skip blanks and `rem` comments.
+    let rcFile = files.open("A:/commandrc")
+    if (rcFile.exists) {
+        rcFile.sread().split('\n').forEach((line) => {
+            let t = line.trim()
+            if (t.length > 0 && !/^rem(\s|$)/i.test(t)) runBatch(line)
+        })
+    }
+
+    if (typeof _TVDOS_IS_VT_PANE === "undefined" || !_TVDOS_IS_VT_PANE) {
+        serial.println(`TVDOS.SYS initialised on VM ${sys.getVmId()}, running boot script...`);
+        // Boot console: hand the screen to the virtual-console multiplexer.
+        // When it exits (Alt-0), fall through to AUTOEXEC so the console is
+        // never left bare.
+        runBatch("tvdos/sbin/vtmgr")
+        runBatch("\\AUTOEXEC.BAT")
+    }
+    else {
+        serial.println(`TVDOS.SYS re-initialised in VT pane on VM ${sys.getVmId()}`);
+    }
+}

assets/disk0/tvdos/bin/command.js

@@ -30,7 +30,18 @@ function makeHash() {
 const shellID = makeHash()
 
 function print_prompt_text() {
+    // VT pane indicator: shown for VT 2..6, not VT 1 (the default) so the
+    // unmodified prompt is what users see when they never touch virtual
+    // consoles. VT_NUM is set by vtmgr's pane bootstrap.
+    let vtPrefix = ""
+    if (typeof VT_NUM !== "undefined" && VT_NUM > 1) vtPrefix = "[" + VT_NUM + "] "
     if (goFancy) {
+        if (vtPrefix) {
+            con.color_pair(161,253)
+            print(`\u00DD${VT_NUM}`)
+            con.color_pair(253,161)
+            con.addch(16);con.curs_right()
+        }
         con.color_pair(239,161)
         print(" "+CURRENT_DRIVE+":")
         con.color_pair(161,253)
@@ -49,9 +60,9 @@ function print_prompt_text() {
     else {
 //        con.color_pair(253,255)
         if (errorlevel != 0 && errorlevel != "undefined" && errorlevel != undefined)
-            print(CURRENT_DRIVE + ":\\" + shell_pwd.join("\\") + " [" + errorlevel + "]" + PROMPT_TEXT)
+            print(vtPrefix + CURRENT_DRIVE + ":\\" + shell_pwd.join("\\") + " [" + errorlevel + "]" + PROMPT_TEXT)
         else
-            print(CURRENT_DRIVE + ":\\" + shell_pwd.join("\\") + PROMPT_TEXT)
+            print(vtPrefix + CURRENT_DRIVE + ":\\" + shell_pwd.join("\\") + PROMPT_TEXT)
     }
 }
 
@@ -77,56 +88,31 @@ function printmotd() {
     let motd = motdFile.sread().trim()
     let width = con.getmaxyx()[1]
 
+    let ts = require("typesetter")
 
     if (goFancy) {
         let margin = 4
         let internalWidth = width - 2*margin
+        let textWidth = internalWidth - 2  // one space of padding inside each ribbon edge
 
-        con.color_pair(255,253) // white text, transparent back (initial ribbon)
-
-        let [cy, cx] = con.getyx()
-
-        con.mvaddch(cy, 4, 16);con.curs_right();print(' ')
-
-        const PCX_INIT = margin - 2
-        let tcnt = 0
-        let pcx = PCX_INIT
-        con.color_pair(240,253) // black text, white back (first line of text)
-        while (tcnt <= motd.length) {
-            let char = motd.charAt(tcnt)
-
-            if (char != '\n') {
-                // prevent the line starting from ' '
-                if (pcx != PCX_INIT || char != ' ') {
-                    print(motd.charAt(tcnt))
-                }
-                pcx += 1
-            }
-
-            if ('\n' == char || pcx % internalWidth == 0 && pcx != 0 || tcnt == motd.length) {
-                // current line ending
-                let [_, ncx] = con.getyx()
-                for (let k = 0; k < width - margin - ncx + 1; k++) print(' ')
-                con.color_pair(255,253) // white text, transparent back
-                con.addch(17);println()
-
-                if (tcnt == motd.length) break
-
-                // next line header
-                let [ncy, __] = con.getyx()
-                con.color_pair(255,253) // white text, transparent back
-                con.mvaddch(ncy, 4, 16);con.curs_right();print(' ');con.color_pair(240,253) // black text, white back (subsequent lines of the text)
-                pcx = PCX_INIT
-            }
-
-            tcnt += 1
-        }
-
+        let lines = ts.typeset(motd, textWidth)
+        lines.forEach(line => {
+            let [cy, _cx] = con.getyx()
+            con.color_pair(255,253) // ribbon edge: white text, transparent back
+            con.mvaddch(cy, margin, 16); con.curs_right()
+            print(' ')
+            con.color_pair(240,253) // body: black text, white back
+            print(line)
+            con.color_pair(255,253)
+            print(' ')
+            con.addch(17); println()
+        })
         con.reset_graphics()
     }
     else {
         println()
-        println(motd)
+        let lines = ts.typeset(motd, width)
+        lines.forEach(line => println(line))
     }
 
     println()
@@ -203,6 +189,19 @@ shell.replaceVarCall = function(value) {
 shell.getPwd = function() { return shell_pwd; }
 shell.getPwdString = function() { return "\\" + (shell_pwd.concat([""])).join("\\"); }
 shell.getCurrentDrive = function() { return CURRENT_DRIVE; }
+shell.runningScriptPaths = []
+shell.getFilePath = function() {
+    return shell.runningScriptPaths[shell.runningScriptPaths.length - 1]
+}
+shell.getFileDir = function() {
+    let p = shell.runningScriptPaths[shell.runningScriptPaths.length - 1]
+    if (p === undefined) return undefined
+    let lastSlash = Math.max(p.lastIndexOf('\\'), p.lastIndexOf('/'))
+    if (lastSlash < 0) return p
+    // root of a drive (e.g. "A:\foo.js" -> "A:\")
+    if (lastSlash === 2 && p[1] === ':') return p.substring(0, 3)
+    return p.substring(0, lastSlash)
+}
 // example input: echo "the string" > subdir\test.txt
 shell.parse = function(input) {
     let tokens = []
@@ -577,8 +576,76 @@ shell.coreutils = {
     ver: function(args) {
         println(welcome_text)
     },
+    which: function(args) {
+        if (args[1] === undefined) {
+            printerrln(`Usage: ${args[0].toUpperCase()} program_name`)
+            return 1
+        }
+        let cmd = args[1]
+
+        if (shell.coreutils[cmd.toLowerCase()] !== undefined) {
+            println(`${cmd}: shell built-in command`)
+            return 0
+        }
+
+        var fileExists = false
+        var searchFile
+        var searchPath = ""
+
+        if (shell.isValidDriveLetter(cmd[0]) && cmd[1] == ':') {
+            searchFile = files.open(cmd)
+            searchPath = trimStartRevSlash(searchFile.path)
+            fileExists = searchFile.exists
+        }
+        else {
+            var searchDir = (cmd.startsWith("/")) ? [""] : ["/"+shell_pwd.join("/")].concat(_TVDOS.getPath())
+
+            var pathExt = []
+            if (cmd.split(".")[1] === undefined)
+                _TVDOS.variables.PATHEXT.split(';').forEach(function(it) { pathExt.push(it); pathExt.push(it.toUpperCase()); })
+            else
+                pathExt.push("")
+
+            searchLoop:
+            for (var i = 0; i < searchDir.length; i++) {
+                for (var j = 0; j < pathExt.length; j++) {
+                    let search = searchDir[i]; if (!search.endsWith('\\')) search += '\\'
+                    searchPath = trimStartRevSlash(search + cmd + pathExt[j])
+
+                    searchFile = files.open(`${CURRENT_DRIVE}:\\${searchPath}`)
+                    if (searchFile.exists) {
+                        fileExists = true
+                        break searchLoop
+                    }
+                }
+            }
+        }
+
+        if (!fileExists) {
+            printerrln(`${cmd}: not found`)
+            return 1
+        }
+
+        println(searchFile.fullPath)
+        return 0
+    },
     panic: function(args) {
         throw Error("Panicking command.js")
+    },
+    chvt: function(args) {
+        // Request a switch to another virtual console. Only meaningful when
+        // running inside a pane spawned by vtmgr (VT_CTRL_ADDR is set by the
+        // pane bootstrap). Outside that environment this is a no-op error.
+        if (args[1] === undefined) { printerrln("Usage: chvt N (1..6)"); return 1 }
+        let n = parseInt(args[1])
+        if (isNaN(n) || n < 1 || n > 6) { printerrln("chvt: N must be in 1..6"); return 1 }
+        if (typeof VT_CTRL_ADDR === "undefined") {
+            printerrln("chvt: not running under vtmgr (no VT context)"); return 1
+        }
+        // CTRL_SWITCH_REQUEST is byte +1 of the shared CTRL area. Dispatcher
+        // picks this up on its next 30 Hz tick and performs the switch.
+        sys.poke(VT_CTRL_ADDR + 1, n)
+        return 0
     }
 }
 // define command aliases here
@@ -590,14 +657,19 @@ shell.coreutils.ls = shell.coreutils.dir
 shell.coreutils.time = shell.coreutils.date
 shell.coreutils.md = shell.coreutils.mkdir
 shell.coreutils.move = shell.coreutils.mv
+shell.coreutils.where = shell.coreutils.which
 // end of command aliases
 Object.freeze(shell.coreutils)
 shell.stdio = {
     out: {
-        print:      function(s) { sys.print(s) },
-        println:    function(s) { if (s === undefined) sys.print("\n"); else sys.print(s+"\n") },
-        printerr:   function(s) { sys.print("\x1B[31m"+s+"\x1B[m") },
-        printerrln: function(s) { if (s === undefined) sys.print("\n"); else sys.print("\x1B[31m"+s+"\x1B[m\n") },
+        // When running inside a vtmgr virtual console, __VT_OUT routes output
+        // to the pane's text-plane buffer instead of the physical GPU (which
+        // the compositor would otherwise overwrite). Outside a VT the hook is
+        // absent and these fall through to sys.print exactly as before.
+        print:      function(s) { if (globalThis.__VT_OUT) globalThis.__VT_OUT.print(s); else sys.print(s) },
+        println:    function(s) { if (globalThis.__VT_OUT) globalThis.__VT_OUT.println(s); else { if (s === undefined) sys.print("\n"); else sys.print(s+"\n") } },
+        printerr:   function(s) { if (globalThis.__VT_OUT) globalThis.__VT_OUT.printerr(s); else sys.print("\x1B[31m"+s+"\x1B[m") },
+        printerrln: function(s) { if (globalThis.__VT_OUT) globalThis.__VT_OUT.printerrln(s); else { if (s === undefined) sys.print("\n"); else sys.print("\x1B[31m"+s+"\x1B[m\n") } },
     },
     pipe: {
         print:      function(s) { if (shell.getPipe() === undefined) throw Error("No pipe opened"); shell.appendToCurrentPipe(s);  },
@@ -614,13 +686,25 @@ require = function(path) {
     if (path[1] == ":") return shell.require(path)
     else {
         // if the path starts with ".", look for the current directory
-        // if the path starts with [A-Za-z0-9], look for the DOSDIR/includes
+        // if the path starts with [A-Za-z0-9], search through INCLPATH
         if (path[0] == '.') return shell.require(shell.resolvePathInput(path).full + ".mjs")
-        else return shell.require(`A:${_TVDOS.variables.DOSDIR}/include/${path}.mjs`)
+        else {
+            let inclDirs = (_TVDOS.variables.INCLPATH || "").split(';').filter(function(it) { return it.length > 0 })
+            for (let i = 0; i < inclDirs.length; i++) {
+                let dir = inclDirs[i]
+                if (!dir.endsWith('\\') && !dir.endsWith('/')) dir += '\\'
+                let candidate = `${CURRENT_DRIVE}:${dir}${path}.mjs`
+                if (files.open(candidate).exists) return shell.require(candidate)
+            }
+            // no match found; defer to shell.require with the first entry so the error mentions a sensible path
+            let firstDir = inclDirs[0] || `${_TVDOS.variables.DOSDIR}\\include`
+            if (!firstDir.endsWith('\\') && !firstDir.endsWith('/')) firstDir += '\\'
+            return shell.require(`${CURRENT_DRIVE}:${firstDir}${path}.mjs`)
+        }
     }
 }
 
-shell.execute = function(line) {
+shell.execute = function(line, nameOverride) {
     if (0 == line.size) return
     let parsedTokens = shell.parse(line) // echo, "hai", |, less
     let statements = [] // [[echo, "hai"], [less]]
@@ -746,6 +830,8 @@ shell.execute = function(line) {
                 let programCode = searchFile.sread()
                 let extension = searchFile.extension.toUpperCase()
 
+                shell.runningScriptPaths.push(searchFile.fullPath)
+                try {
                 if ("BAT" == extension) {
                     // parse and run as batch file
                     var lines = programCode.split('\n').filter(function(it) { return it.length > 0 }) // this return is not shell's return!
@@ -757,19 +843,28 @@ shell.execute = function(line) {
                     // parse alias
                     // $0: all arguments
                     // $1..9: specific arguments
+                    // Tokens that contain whitespace or shell metacharacters must be re-quoted
+                    // before re-execution, otherwise the re-parse splits them on spaces.
+                    var quoteAliasArg = function(s) {
+                        if (s === undefined || s === null) return ""
+                        s = ''+s
+                        if (s.length === 0) return ""
+                        if (/[\s"|><&]/.test(s)) return '"' + s.replaceAll('"', '^"') + '"'
+                        return s
+                    }
                     var lines = programCode.split('\n').filter(function(it) { return it.length > 0 }) // this return is not shell's return!
                     lines.forEach(function(line) {
                         var newLine = line
 
                         // replace $1..$9
-                        for (let j = 1; j < 9; j++) {
-                            newLine = newLine.replaceAll('$'+j, tokens[j])
+                        for (let j = 1; j <= 9; j++) {
+                            newLine = newLine.replaceAll('$'+j, quoteAliasArg(tokens[j]))
                         }
 
                         // replace $0
-                        newLine = newLine.replaceAll('$0', tokens.slice(1).join(' '))
+                        newLine = newLine.replaceAll('$0', tokens.slice(1).map(quoteAliasArg).join(' '))
 
-                        shell.execute(newLine)
+                        shell.execute(newLine, cmd)
                     })
                 }
                 else if ("APP" == extension) {
@@ -786,6 +881,10 @@ shell.execute = function(line) {
                         errorlevel = 0 // reset the number
 
                         if (_G.shellProgramTitles === undefined) _G.shellProgramTitles = []
+                        if (nameOverride !== undefined) {
+                            tokens[0] = (''+nameOverride)
+                            cmd = tokens[0]
+                        }
                         _G.shellProgramTitles.push(cmd.toUpperCase())
                         sendLcdMsg(_G.shellProgramTitles[_G.shellProgramTitles.length - 1])
                         //serial.println(_G.shellProgramTitles)
@@ -825,6 +924,9 @@ shell.execute = function(line) {
                         continue
                     }
                 }
+                } finally {
+                    shell.runningScriptPaths.pop()
+                }
             }
         }
 
@@ -884,6 +986,192 @@ Object.freeze(shell)
 _G.shell = shell
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// TAB AUTOCOMPLETION
+//
+// Invoked by TAB at the interactive prompt. Only active when BOTH:
+//   1. wintex.mjs is available (provides the selection popup), AND
+//   2. goFancy == true.
+// One candidate  -> expand immediately (no popup).
+// Many candidates -> wintex popup; user scrolls and selects, or Esc/Cancel to
+//                    discard. The popup over-draws the screen without saving
+//                    what was beneath it, so we snapshot the text plane before
+//                    and copy it back after (the shell can't just redraw like a
+//                    full-screen TUI — there's scrollback above the prompt).
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+// Lazily-resolved wintex module. undefined = not probed yet, null = unavailable.
+let _acWin = undefined
+function getAutocompleteWin() {
+    if (_acWin !== undefined) return _acWin
+    _acWin = null
+    try {
+        let w = require("wintex") // resolved through INCLPATH (\tvdos\include\wintex.mjs)
+        if (w && typeof w.showDialog === "function") _acWin = w
+    } catch (e) {
+        debugprintln("command.js > autocomplete: wintex unavailable: " + e)
+    }
+    return _acWin
+}
+
+// List a directory's entries, swallowing any IO error.
+function _acListDir(fullPath) {
+    try {
+        let f = files.open(fullPath)
+        if (!f.exists || !f.isDirectory) return []
+        return f.list() || []
+    } catch (e) { return [] }
+}
+
+// Strip a trailing PATHEXT extension so command names show without ".js" etc.
+function _acStripExt(name) {
+    let lower = name.toLowerCase()
+    let exts = (_TVDOS.variables.PATHEXT || "").split(';').filter(function(e){ return e.length > 0 })
+    for (let i = 0; i < exts.length; i++) {
+        let e = exts[i].toLowerCase()
+        if (lower.endsWith(e)) return name.substring(0, name.length - e.length)
+    }
+    return name
+}
+
+// Candidates for the command position (first word, no path separators):
+// shell built-ins + runnable files found along the current dir, drive root and PATH.
+function _acCommandCandidates(prefix) {
+    let lower = prefix.toLowerCase()
+    let seen = {}
+    let out = []
+    function add(name) {
+        let k = name.toLowerCase()
+        if (seen[k]) return
+        seen[k] = true
+        out.push({ label: name, value: name + ' ', isDir: false })
+    }
+
+    // shell built-ins (and their aliases)
+    Object.keys(shell.coreutils).forEach(function(k) {
+        if (k.toLowerCase().startsWith(lower)) add(k)
+    })
+
+    // runnable files: search the same places shell.execute does, in the same order
+    let exts = (_TVDOS.variables.PATHEXT || "").split(';')
+        .filter(function(e){ return e.length > 0 }).map(function(e){ return e.toLowerCase() })
+    let dirFulls = [shell.resolvePathInput('.').full] // current directory first
+    _TVDOS.getPath().forEach(function(d) {
+        dirFulls.push((d === '' || d === undefined) ? `${CURRENT_DRIVE}:\\` : shell.resolvePathInput(d).full)
+    })
+    dirFulls.forEach(function(full) {
+        _acListDir(full).forEach(function(it) {
+            if (it.isDirectory) return
+            let nameLower = (it.name || '').toLowerCase()
+            if (!exts.some(function(e){ return nameLower.endsWith(e) })) return // only runnables
+            let stripped = _acStripExt(it.name)
+            if (stripped.toLowerCase().startsWith(lower)) add(stripped)
+        })
+    })
+    return out
+}
+
+// Candidates for a path argument. The word may carry a directory prefix
+// (kept verbatim) and a partial basename that we match against the directory.
+function _acPathCandidates(word) {
+    let sepIdx = Math.max(word.lastIndexOf('\\'), word.lastIndexOf('/'))
+    let dirPart, basePart, listArg
+    if (sepIdx >= 0) {
+        dirPart  = word.substring(0, sepIdx + 1) // includes the trailing separator
+        basePart = word.substring(sepIdx + 1)
+        listArg  = dirPart
+    } else {
+        dirPart  = ''
+        basePart = word
+        listArg  = '.'
+    }
+    let resolved = shell.resolvePathInput(listArg)
+    if (resolved === undefined) return []
+    let sep = (dirPart.length > 0 && dirPart.charAt(dirPart.length - 1) === '/') ? '/' : '\\'
+    let lower = basePart.toLowerCase()
+    let out = []
+    _acListDir(resolved.full).forEach(function(it) {
+        let name = it.name || ''
+        if (!name.toLowerCase().startsWith(lower)) return
+        out.push({
+            // directories get a trailing separator so completion can continue into them;
+            // files get a trailing space so the next argument can be typed straight away.
+            label: name + (it.isDirectory ? '\\' : ''),
+            value: dirPart + name + (it.isDirectory ? sep : ' '),
+            isDir: it.isDirectory
+        })
+    })
+    return out
+}
+
+// Work out what is being completed at `caret` within `line`.
+// Returns { wordStart, word, candidates } (candidates sorted by label).
+function computeCompletion(line, caret) {
+    let wordStart = caret
+    while (wordStart > 0 && line.charAt(wordStart - 1) !== ' ') wordStart -= 1
+    let word = line.substring(wordStart, caret)
+    let isFirstWord = (line.substring(0, wordStart).trim().length === 0)
+    let hasPathSep = (word.indexOf('\\') >= 0 || word.indexOf('/') >= 0 || word.indexOf(':') >= 0)
+    let candidates = (isFirstWord && !hasPathSep) ? _acCommandCandidates(word) : _acPathCandidates(word)
+    candidates.sort(function(a, b) { return (a.label < b.label) ? -1 : (a.label > b.label) ? 1 : 0 })
+    return { wordStart: wordStart, word: word, candidates: candidates }
+}
+
+// --- text-plane snapshot/restore (so the popup leaves no artefacts) ---------
+// In a vtmgr pane the shimmed con/print draw into the pane buffer
+// (globalThis.VT_TEXT_PLANE, forward layout); on the physical console they
+// draw into the GPU text area (mapped at getGpuMemBase()-253950). vaddr(0) is
+// that base in either case; sys.memcpy reads/writes it forward-native.
+// NOTE: 7681, not the full 7682-byte text area: relPtrInDev() bounds-checks
+// `from+len` inclusively, so the final byte (bottom-right char cell, never
+// touched by a centred popup) is unreachable by a single memcpy.
+const _AC_TEXTAREA_BYTES = 7681
+let _acTextBase = null
+let _acScratchPtr = 0
+function _acTextAreaBase() {
+    if (_acTextBase === null) {
+        _acTextBase = (typeof globalThis.VT_TEXT_PLANE !== 'undefined')
+            ? globalThis.VT_TEXT_PLANE
+            : (graphics.getGpuMemBase() - 253950)
+    }
+    return _acTextBase
+}
+function _acSnapshotScreen() {
+    if (_acScratchPtr === 0) _acScratchPtr = sys.malloc(_AC_TEXTAREA_BYTES)
+    sys.memcpy(_acTextAreaBase(), _acScratchPtr, _AC_TEXTAREA_BYTES)
+}
+function _acRestoreScreen() {
+    if (_acScratchPtr === 0) return
+    sys.memcpy(_acScratchPtr, _acTextAreaBase(), _AC_TEXTAREA_BYTES)
+}
+
+// Modal popup of candidates. Returns the chosen item, or null if discarded.
+function _acShowPopup(win, candidates) {
+    let res = win.showDialog({
+        title: `Complete (${candidates.length})`,
+        list: {
+            items: candidates,
+            height: Math.min(12, candidates.length),
+            onActivate: function(item, idx, key) { return 'select' }
+        },
+        buttons: [{ label: 'Cancel', action: 'cancel' }]
+    })
+    if (res && res.action === 'select' && res.listItem) return res.listItem
+    return null
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+// ensure USERCONFIGPATH directory exists
+try {
+    let userConfigPath = `${CURRENT_DRIVE}:${_TVDOS.variables.USERCONFIGPATH}`
+    let userConfigDir = files.open(userConfigPath)
+    if (!userConfigDir.exists) {
+        debugprintln(`command.js > creating USERCONFIGPATH at ${userConfigPath}`)
+        userConfigDir.mkDir()
+    }
+} catch (e) {
+    debugprintln("command.js > USERCONFIGPATH creation failed: " + e.message)
+}
 
 if (exec_args[1] !== undefined) {
     // only meaningful switches would be either -c or -k anyway
@@ -928,23 +1216,133 @@ if (goInteractive) {
         print_prompt_text()
 
         var cmdbuf = ""
+        var caret = 0 // insertion point within cmdbuf, 0..cmdbuf.length
+
+        // Self-contained line editor with a movable caret (so command.js does
+        // NOT depend on wintex being installed). The prompt has just been
+        // printed, so the current cursor marks where the editable text begins.
+        // We track that anchor and rebuild the on-screen line from it, decoding
+        // line-wrap ourselves so the maths holds in both the physical console
+        // and a vtmgr pane (whose con.move CLAMPS x instead of wrapping it).
+        let [baseY, baseX] = con.getyx() // 1-based
+        let termCols = con.getmaxyx()[1]
+
+        // absolute (y,x) on screen for caret index `idx`
+        function caretPos(idx) {
+            let abs = (baseX - 1) + idx
+            return [baseY + ((abs / termCols) | 0), (abs % termCols) + 1]
+        }
+        function gotoCaret() {
+            let [cy, cx] = caretPos(caret)
+            con.move(cy, cx)
+        }
+        // reprint cmdbuf from index `from` to the end, optionally padding with
+        // `clearTrail` blanks to wipe characters left over by a now-shorter
+        // line, then park the hardware cursor back on the caret.
+        function refresh(from, clearTrail) {
+            let [py, px] = caretPos(from)
+            con.move(py, px)
+            print(cmdbuf.substring(from))
+            for (let i = 0; i < clearTrail; i++) print(" ")
+            gotoCaret()
+        }
+        // replace the whole buffer (used by history recall)
+        function setBuf(next) {
+            let oldLen = cmdbuf.length
+            cmdbuf = next
+            caret = cmdbuf.length
+            refresh(0, Math.max(0, oldLen - cmdbuf.length))
+        }
+
+        // Replace the word [wordStart, caret) with `value`, keeping any text to
+        // the right of the caret, then reprint the line from `wordStart`.
+        function applyCompletion(wordStart, value) {
+            let oldLen = cmdbuf.length
+            cmdbuf = cmdbuf.substring(0, wordStart) + value + cmdbuf.substring(caret)
+            caret = wordStart + value.length
+            con.color_pair(shell.usrcfg.textCol, 255)
+            refresh(wordStart, Math.max(0, oldLen - cmdbuf.length))
+        }
+
+        // TAB handler. No-op unless fancy mode is on and wintex is installed.
+        function tryAutocomplete() {
+            if (!goFancy) return
+            let win = getAutocompleteWin()
+            if (!win) return
+
+            let comp = computeCompletion(cmdbuf, caret)
+            let cands = comp.candidates
+            if (cands.length === 0) return
+            if (cands.length === 1) { applyCompletion(comp.wordStart, cands[0].value); return }
+
+            _acSnapshotScreen()
+            let chosen = _acShowPopup(win, cands)
+            _acRestoreScreen()
+
+            // The popup drives input through input.withEvent (physical held-key
+            // state), which bypasses the buffer con.getch reads. Inside a vtmgr
+            // pane the dispatcher keeps draining physical keystrokes into this
+            // pane's input ring the whole time the popup is open, so the navigation
+            // keys (and the closing Enter) would otherwise surface as phantom input
+            // afterwards. Flush them. (On the physical console readKey self-clears,
+            // so this is harmless there.)
+            con.resetkeybuf()
+
+            // The popup hid the caret and clobbered colours; restore the prompt
+            // editing state. The screen content is already back from the snapshot.
+            con.curs_set(1)
+            con.color_pair(shell.usrcfg.textCol, 255)
+            gotoCaret()
+
+            if (chosen) applyCompletion(comp.wordStart, chosen.value)
+        }
 
         while (true) {
             let key = con.getch()
 
             // printable chars
             if (key >= 32 && key <= 126) {
-                var s = String.fromCharCode(key)
-                cmdbuf += s
-                print(s)
+                let s = String.fromCharCode(key)
+                let atEnd = (caret === cmdbuf.length)
+                cmdbuf = cmdbuf.substring(0, caret) + s + cmdbuf.substring(caret)
+                caret += 1
+                if (atEnd) print(s) // fast path: simple append
+                else refresh(caret - 1, 0)
             }
-            // backspace
-            else if (key === con.KEY_BACKSPACE && cmdbuf.length > 0) {
-                cmdbuf = cmdbuf.substring(0, cmdbuf.length - 1)
-                print(String.fromCharCode(key))
+            // TAB: autocomplete (fancy mode + wintex only; otherwise a no-op)
+            else if (key === con.KEY_TAB) {
+                tryAutocomplete()
+            }
+            // backspace: delete the char to the left of the caret
+            else if (key === con.KEY_BACKSPACE && caret > 0) {
+                cmdbuf = cmdbuf.substring(0, caret - 1) + cmdbuf.substring(caret)
+                caret -= 1
+                refresh(caret, 1)
+            }
+            // forward delete: delete the char under the caret
+            else if (key === con.KEY_DELETE && caret < cmdbuf.length) {
+                cmdbuf = cmdbuf.substring(0, caret) + cmdbuf.substring(caret + 1)
+                refresh(caret, 1)
+            }
+            // caret left
+            else if (key === con.KEY_LEFT) {
+                if (caret > 0) { caret -= 1; gotoCaret() }
+            }
+            // caret right
+            else if (key === con.KEY_RIGHT) {
+                if (caret < cmdbuf.length) { caret += 1; gotoCaret() }
+            }
+            // jump to start of line
+            else if (key === con.KEY_HOME) {
+                caret = 0; gotoCaret()
+            }
+            // jump to end of line
+            else if (key === con.KEY_END) {
+                caret = cmdbuf.length; gotoCaret()
             }
             // enter
             else if (key === 10 || key === con.KEY_RETURN) {
+                caret = cmdbuf.length; gotoCaret()
                 println()
 
                 errorlevel = shell.execute(cmdbuf)
@@ -960,32 +1358,17 @@ if (goInteractive) {
             // up arrow
             else if (key === con.KEY_UP && cmdHistory.length > 0 && cmdHistoryScroll < cmdHistory.length) {
                 cmdHistoryScroll += 1
-
-                // back the cursor in order to type new cmd
-                var x = 0
-                for (x = 0; x < cmdbuf.length; x++) print(String.fromCharCode(8))
-                cmdbuf = cmdHistory[cmdHistory.length - cmdHistoryScroll]
-                // re-type the new command
-                print(cmdbuf)
-
+                setBuf(cmdHistory[cmdHistory.length - cmdHistoryScroll])
             }
             // down arrow
             else if (key === con.KEY_DOWN) {
-                if (cmdHistoryScroll > 0) {
-                    // back the cursor in order to type new cmd
-                    var x = 0
-                    for (x = 0; x < cmdbuf.length; x++) print(String.fromCharCode(8))
-                    cmdbuf = cmdHistory[cmdHistory.length - cmdHistoryScroll]
-                    // re-type the new command
-                    print(cmdbuf)
-
+                if (cmdHistoryScroll > 1) {
                     cmdHistoryScroll -= 1
+                    setBuf(cmdHistory[cmdHistory.length - cmdHistoryScroll])
                 }
-                else {
-                    // back the cursor in order to type new cmd
-                    var x = 0
-                    for (x = 0; x < cmdbuf.length; x++) print(String.fromCharCode(8))
-                    cmdbuf = ""
+                else if (cmdHistoryScroll === 1) {
+                    cmdHistoryScroll = 0
+                    setBuf("")
                 }
             }
         }

assets/disk0/tvdos/bin/hop.alias

@@ -0,0 +1 @@
+hopper $0

assets/disk0/tvdos/bin/hopper.js

@@ -1,5 +1,956 @@
 /**
- * Hopper is a package manager for TSVM
+ * Hopper is a package manager for TVDOS
  * Created by CuriousTorvald on 2026-04-16
  */
 
+const SYSTEM_PACKEAGE_DEF_DIR  = "A:/tvdos/hopper"
+const USER_BASE_DIR            = "A:/hopper"
+const USER_PACKAGE_DEF_DIR     = `${USER_BASE_DIR}/manifests`
+const USER_PACKAGE_BIN_DIR     = `${USER_BASE_DIR}/bin`
+const USER_PACKAGE_INCLUDE_DIR = `${USER_BASE_DIR}/include`
+const MANIFEST_EXT = "hop.per"
+const MIRROR_LIST_PATH = `${SYSTEM_PACKEAGE_DEF_DIR}/mirrors.list`
+
+const net = require("net")
+
+// SYNOPSIS
+// hopper {search,se} [--provides, --requires, --description, --author] query
+//// default searches from ProperName
+// hopper {install,in} query [-v version]
+// hopper {remove,rm} query
+
+// ============================================================
+// Manifest parsing
+// ============================================================
+
+function splitList(s) {
+    if (!s) return []
+    return s.split(";").map(it => it.trim()).filter(it => it.length > 0)
+}
+
+function parseManifest(text) {
+    const m = {}
+    text.split("\n").forEach(rawLine => {
+        const line = rawLine.replace(/\r$/, "")
+        if (line.length === 0) return
+        const idx = line.indexOf(":")
+        if (idx < 0) return
+        const key = line.substring(0, idx).trim()
+        const value = line.substring(idx + 1).trim()
+        m[key] = value
+    })
+    return m
+}
+
+function readManifestFile(path) {
+    const f = files.open(path)
+    if (!f.exists || f.isDirectory) return undefined
+    const m = parseManifest(f.sread())
+    m._manifestPath = path
+    return m
+}
+
+function _listManifestsFrom(dirPath, origin) {
+    const dir = files.open(dirPath)
+    if (!dir.exists || !dir.isDirectory) return []
+    const out = []
+    dir.list().forEach(entry => {
+        if (entry.isDirectory) return
+        if (!entry.name.toLowerCase().endsWith(MANIFEST_EXT)) return
+        const m = readManifestFile(entry.fullPath)
+        if (m !== undefined) {
+            m._origin = origin
+            out.push(m)
+        }
+    })
+    return out
+}
+
+// System packages (shipped with TVDOS) live in SYSTEM_PACKAGE_DEF_DIR
+// and are read-only as far as hopper is concerned. User packages,
+// installed by `hopper install`, live under USER_PACKAGE_DEF_DIR. The
+// resolver treats both as "installed", but the install/remove paths
+// refuse to modify anything tagged `_origin === "system"`.
+function listInstalledManifests() {
+    return _listManifestsFrom(SYSTEM_PACKEAGE_DEF_DIR, "system")
+        .concat(_listManifestsFrom(USER_PACKAGE_DEF_DIR, "user"))
+}
+
+function findInstalledManifest(name) {
+    // Prefer user-installed copy when a system package with the same name
+    // also exists -- but that combination is normally refused at install.
+    const userDirect = `${USER_PACKAGE_DEF_DIR}/${name}.${MANIFEST_EXT}`
+    let m = readManifestFile(userDirect)
+    if (m !== undefined) { m._origin = "user"; return m }
+
+    const sysDirect = `${SYSTEM_PACKEAGE_DEF_DIR}/${name}.${MANIFEST_EXT}`
+    m = readManifestFile(sysDirect)
+    if (m !== undefined) { m._origin = "system"; return m }
+
+    const all = listInstalledManifests()
+    for (let i = 0; i < all.length; i++) {
+        if ((all[i].HopperPackageName || "") === name) return all[i]
+    }
+    return undefined
+}
+
+// Yes/no prompt. Empty input falls back to `defaultYes`.
+function confirm(prompt, defaultYes) {
+    const hint = defaultYes ? "[Y/n]" : "[y/N]"
+    print(`${prompt} ${hint} `)
+    const ans = (read() || "").trim().toLowerCase()
+    if (ans === "") return !!defaultYes
+    return ans === "y" || ans === "yes"
+}
+
+// ============================================================
+// Install layout helpers
+// ============================================================
+//
+// User-installed packages live under `A:/hopper/`. Files are routed
+// by extension: `.mjs` includes go under `include/`, everything else
+// (`.js`, `.alias`, `.lfs`, data blobs, ...) lands in `bin/`. The
+// downloaded manifest is saved under `manifests/` with a
+// `SystemPackagePath` field appended that lists the resulting paths.
+
+// Strip query/fragment and take the last `/`-separated component of `url`.
+function urlBasename(url) {
+    let s = String(url || "")
+    const qm = s.indexOf("?");   if (qm   >= 0) s = s.substring(0, qm)
+    const hash = s.indexOf("#"); if (hash >= 0) s = s.substring(0, hash)
+    const slash = s.lastIndexOf("/")
+    return (slash < 0) ? s : s.substring(slash + 1)
+}
+
+function routeForBasename(name) {
+    return (String(name || "").toLowerCase().endsWith(".mjs"))
+        ? USER_PACKAGE_INCLUDE_DIR
+        : USER_PACKAGE_BIN_DIR
+}
+
+// Convert a USER_BASE_DIR-relative absolute path ("A:/hopper/bin/foo.js")
+// into its declarable form ("/hopper/bin/foo.js"), matching the
+// `SystemPackagePath` convention used by the system manifests.
+function declarablePath(absPath) {
+    let p = String(absPath || "").replace(/\\/g, "/")
+    if (/^[A-Za-z]:/.test(p)) p = p.substring(2)
+    return p
+}
+
+// Parse PackageFileList (semicolon-separated full URLs) into a list of
+// download descriptors: { url, basename, localPath }.
+function parsePackageFileList(s) {
+    const out = []
+    splitList(s || "").forEach(url => {
+        const base = urlBasename(url)
+        if (base.length === 0) return
+        const dir  = routeForBasename(base)
+        out.push({ url: url, basename: base, localPath: `${dir}/${base}` })
+    })
+    return out
+}
+
+function ensureUserDirs() {
+    [USER_BASE_DIR, USER_PACKAGE_BIN_DIR, USER_PACKAGE_INCLUDE_DIR, USER_PACKAGE_DEF_DIR].forEach(p => {
+        const d = files.open(p)
+        if (!d.exists) d.mkDir()
+    })
+}
+
+// Re-emit a parsed manifest, preserving insertion order, dropping
+// internal `_*` keys, and replacing any pre-existing SystemPackagePath
+// with the locally-computed one so the field always reflects what is
+// actually on disk.
+function serializeManifest(manifestObj, installedPathStr) {
+    const lines = []
+    Object.keys(manifestObj).forEach(k => {
+        if (k.length > 0 && k[0] === "_") return
+        if (k === "SystemPackagePath") return
+        lines.push(`${k}:${manifestObj[k]}`)
+    })
+    lines.push(`SystemPackagePath:${installedPathStr}`)
+    return lines.join("\n") + "\n"
+}
+
+// Delete every file declared in `manifest.SystemPackagePath` plus the
+// manifest file itself. Wildcards are expanded via `expandSystemPath`.
+function deleteInstalledFiles(manifest) {
+    const removed = []
+    splitList(manifest.SystemPackagePath || "").forEach(p => {
+        expandSystemPath(p).forEach(abs => {
+            const fd = files.open(abs)
+            if (!fd.exists) return
+            try { fd.remove(); removed.push(abs) }
+            catch (e) { printerrln(`  ! failed to remove ${abs}: ${e}`) }
+        })
+    })
+    if (manifest._manifestPath) {
+        const mfd = files.open(manifest._manifestPath)
+        if (mfd.exists) {
+            try { mfd.remove(); removed.push(manifest._manifestPath) }
+            catch (e) { printerrln(`  ! failed to remove ${manifest._manifestPath}: ${e}`) }
+        }
+    }
+    return removed
+}
+
+// ============================================================
+// SemVer (strict X.Y.Z) and constraint matching
+// ============================================================
+//
+// Versions are strict Semantic Versioning: three non-negative integer
+// components MAJOR.MINOR.PATCH. No pre-release / build metadata.
+//
+// Constraint grammar (intentionally small, expandable later):
+//   *           any version
+//   X.*         major X, any minor/patch
+//   X.Y.*       major X, minor Y, any patch
+//   X.Y.Z       exact
+//   ^X.Y.Z      >= X.Y.Z and < (X+1).0.0  (major-compatible)
+//   ~X.Y.Z      >= X.Y.Z and < X.(Y+1).0  (minor-compatible)
+//   >=X.Y.Z / >X.Y.Z / <=X.Y.Z / <X.Y.Z / =X.Y.Z
+//
+// Multiple comma-separated constraints are AND-ed: "^1.2.0,<1.5.0".
+
+function parseVersion(v) {
+    const m = String(v || "0.0.0").trim().match(/^(\d+)\.(\d+)\.(\d+)$/)
+    if (!m) return [0, 0, 0]
+    return [parseInt(m[1], 10), parseInt(m[2], 10), parseInt(m[3], 10)]
+}
+
+function compareVersion(a, b) {
+    const A = parseVersion(a), B = parseVersion(b)
+    for (let i = 0; i < 3; i++) {
+        if (A[i] !== B[i]) return (A[i] < B[i]) ? -1 : 1
+    }
+    return 0
+}
+
+function _matchSingleConstraint(version, c) {
+    c = c.trim()
+    if (c === "" || c === "*") return true
+
+    // Operator form: ^, ~, >=, <=, >, <, =
+    let opMatch = c.match(/^(\^|~|>=|<=|>|<|=)\s*(\d+\.\d+\.\d+)$/)
+    if (opMatch) {
+        const op = opMatch[1]
+        const target = opMatch[2]
+        const cmp = compareVersion(version, target)
+        const [tM, tm] = parseVersion(target)
+        switch (op) {
+            case "=":  return cmp === 0
+            case ">":  return cmp >  0
+            case ">=": return cmp >= 0
+            case "<":  return cmp <  0
+            case "<=": return cmp <= 0
+            case "^":  return cmp >= 0 && compareVersion(version, `${tM + 1}.0.0`) < 0
+            case "~":  return cmp >= 0 && compareVersion(version, `${tM}.${tm + 1}.0`) < 0
+        }
+    }
+
+    // Wildcard form: X.*, X.Y.*, X.x, X.Y.x, or exact X.Y.Z
+    const parts = c.split(".")
+    const vparts = parseVersion(version)
+    for (let i = 0; i < parts.length && i < 3; i++) {
+        if (parts[i] === "*" || parts[i] === "x" || parts[i] === "X") return true
+        const expected = parseInt(parts[i], 10)
+        if (isNaN(expected) || vparts[i] !== expected) return false
+    }
+    // All listed parts matched literally; remaining parts (if any) must be 0
+    for (let i = parts.length; i < 3; i++) {
+        if (vparts[i] !== 0) return false
+    }
+    return true
+}
+
+function satisfies(version, constraint) {
+    if (!constraint) return true
+    return constraint.split(",").every(c => _matchSingleConstraint(version, c))
+}
+
+function parseRequires(s) {
+    const out = []
+    splitList(s || "").forEach(entry => {
+        // "<name>" or "<name> <constraint>"
+        const idx = entry.search(/\s+/)
+        if (idx < 0) {
+            out.push({ name: entry, constraint: "*" })
+        } else {
+            out.push({ name: entry.substring(0, idx), constraint: entry.substring(idx + 1).trim() })
+        }
+    })
+    return out
+}
+
+// HopperProvides entries are "<name>" or "<name> <version>". A bare name
+// falls back to the package's own HopperPackageVersion — the same idea
+// as RPM's `Provides: aalib = 1.2.0` (where the package's real name and
+// version may differ from the virtual identity it exposes).
+function parseProvides(s, fallbackVersion) {
+    const out = []
+    splitList(s || "").forEach(entry => {
+        const idx = entry.search(/\s+/)
+        if (idx < 0) {
+            out.push({ name: entry, version: fallbackVersion })
+        } else {
+            const v = entry.substring(idx + 1).trim()
+            out.push({ name: entry.substring(0, idx), version: v || fallbackVersion })
+        }
+    })
+    return out
+}
+
+// Look up the version a candidate exposes for `name`. If `name` matches
+// the package's own name (or isn't declared in HopperProvides at all),
+// returns the package's own version.
+function providedVersionOf(candidate, name) {
+    if (candidate.provides) {
+        for (let i = 0; i < candidate.provides.length; i++) {
+            if (candidate.provides[i].name === name) return candidate.provides[i].version
+        }
+    }
+    return candidate.version
+}
+
+// ============================================================
+// Candidate index (installed + upstream)
+// ============================================================
+
+function _manifestToCandidate(m, source) {
+    const name    = m.HopperPackageName || ""
+    const version = m.HopperPackageVersion || "0.0.0"
+    const provides = parseProvides(m.HopperProvides || "", version)
+    // Every package implicitly provides itself at its own version. Only
+    // synthesise this when the manifest didn't declare it explicitly.
+    if (name && !provides.some(p => p.name === name)) {
+        provides.unshift({ name: name, version: version })
+    }
+    return {
+        name:     name,
+        version:  version,
+        requires: parseRequires(m.HopperRequires || ""),
+        provides: provides,
+        source:   source, // "installed" | "upstream"
+        manifest: m
+    }
+}
+
+// Returns map: packageName -> array<Candidate>
+function buildCandidateIndex() {
+    const idx = new Map()
+    function add(c) {
+        if (!idx.has(c.name)) idx.set(c.name, [])
+        // De-dupe (name+version+source)
+        const arr = idx.get(c.name)
+        if (arr.some(x => x.version === c.version && x.source === c.source)) return
+        arr.push(c)
+    }
+
+    listInstalledManifests().forEach(m => add(_manifestToCandidate(m, "installed")))
+    fetchRemoteCandidates().forEach(m => add(_manifestToCandidate(m, "upstream")))
+
+    return idx
+}
+
+// Anything that satisfies a requirement on `name`: a package whose own
+// HopperPackageName matches OR whose HopperProvides declares `name`.
+// Each candidate now carries `provides` as {name, version} pairs; the
+// package's own (name, version) is always present (see
+// _manifestToCandidate), so a single pass over `provides` is enough.
+function findProviders(idx, name) {
+    const out = []
+    const seen = new Set()
+    idx.forEach(candidates => {
+        candidates.forEach(c => {
+            if (seen.has(c)) return
+            if (c.provides.some(p => p.name === name)) {
+                out.push(c)
+                seen.add(c)
+            }
+        })
+    })
+    return out
+}
+
+// Sort: installed first (no churn), then highest version, then upstream order.
+function sortCandidates(cands) {
+    return cands.slice().sort((a, b) => {
+        if (a.source !== b.source) return (a.source === "installed") ? -1 : 1
+        return -compareVersion(a.version, b.version)
+    })
+}
+
+// ============================================================
+// Resolver (snapshot-based backtracking; precursor to a SAT solver)
+// ============================================================
+//
+// State: chosen :: Map<packageName, Candidate>
+// At every choice point we snapshot the whole map so that backtracking
+// also undoes any transitive picks. The candidate ordering encodes the
+// preference policy:
+//
+//   1. Keep installed if it satisfies the constraint.
+//   2. Otherwise pick the newest upstream version that satisfies.
+//   3. If newer versions cause downstream conflicts, walk older versions
+//      (downgrade) until either something fits or candidates are exhausted.
+//
+// The structure is intentionally close to DPLL: each "decision" is the
+// candidate we assign to a variable, and "unit propagation" is the
+// recursive resolve() call over each requirement. Replacing this with
+// clause learning / a watched-literals scheme later would be local.
+
+function resolveAll(idx, requirements) {
+    const chosen = new Map()
+    const issues = []
+
+    function snapshot()           { return new Map(chosen) }
+    function restore(snap)        { chosen.clear(); snap.forEach((v, k) => chosen.set(k, v)) }
+
+    function _resolve(reqName, constraint, trail) {
+        const existing = chosen.get(reqName)
+        if (existing !== undefined) {
+            const v = providedVersionOf(existing, reqName)
+            return satisfies(v, constraint)
+                ? { ok: true }
+                : { ok: false, reason: `${reqName} pinned to ${v}, but ${trail.join(" -> ")} requires ${constraint}` }
+        }
+
+        const providers = findProviders(idx, reqName)
+        if (providers.length === 0) {
+            return { ok: false, reason: `no package provides "${reqName}" (required by ${trail.join(" -> ") || "<root>"})` }
+        }
+        // Satisfaction checks the virtual version the candidate exposes
+        // for `reqName` (HopperProvides), not necessarily the package's
+        // own HopperPackageVersion.
+        const matching = sortCandidates(providers.filter(c => satisfies(providedVersionOf(c, reqName), constraint)))
+        if (matching.length === 0) {
+            const versions = providers.map(p => `${providedVersionOf(p, reqName)}[${p.source}]`).join(", ")
+            return { ok: false, reason: `no version of "${reqName}" satisfies ${constraint} (available: ${versions})` }
+        }
+
+        let lastReason = null
+        for (let i = 0; i < matching.length; i++) {
+            const cand = matching[i]
+            const snap = snapshot()
+            chosen.set(cand.name, cand)
+
+            let allOk = true
+            const subTrail = trail.concat([`${cand.name}@${cand.version}`])
+            for (let j = 0; j < cand.requires.length; j++) {
+                const req = cand.requires[j]
+                const r = _resolve(req.name, req.constraint, subTrail)
+                if (!r.ok) {
+                    allOk = false
+                    lastReason = r.reason
+                    break
+                }
+            }
+            if (allOk) return { ok: true }
+            restore(snap)
+        }
+
+        return { ok: false, reason: lastReason || `no working candidate for "${reqName}"` }
+    }
+
+    requirements.forEach(req => {
+        const r = _resolve(req.name, req.constraint, [])
+        if (!r.ok) issues.push(r.reason)
+    })
+
+    return { chosen, issues }
+}
+
+// Compare resolved assignment against currently-installed state.
+function classifyPlan(idx, chosen) {
+    const installedByName = new Map()
+    listInstalledManifests().forEach(m => installedByName.set(m.HopperPackageName, m))
+
+    const actions = []
+    chosen.forEach((cand, name) => {
+        const inst = installedByName.get(name)
+        if (cand.source === "installed") {
+            actions.push({ action: "keep", name, version: cand.version })
+        }
+        else if (inst === undefined) {
+            actions.push({ action: "install", name, version: cand.version })
+        }
+        else {
+            const cmp = compareVersion(cand.version, inst.HopperPackageVersion)
+            if      (cmp > 0) actions.push({ action: "upgrade",   name, from: inst.HopperPackageVersion, to: cand.version })
+            else if (cmp < 0) actions.push({ action: "downgrade", name, from: inst.HopperPackageVersion, to: cand.version })
+            else              actions.push({ action: "reinstall", name, version: cand.version })
+        }
+    })
+    return actions
+}
+
+function printPlan(actions, target) {
+    const changing = actions.filter(a => a.action !== "keep")
+    if (changing.length === 0) {
+        println(`Nothing to do: ${target} is already installed and satisfied.`)
+        return
+    }
+    println("Plan:")
+    changing.forEach(a => {
+        switch (a.action) {
+            case "install":   println(`  + install    ${a.name} ${a.version}`); break
+            case "upgrade":   println(`  ^ upgrade    ${a.name} ${a.from} -> ${a.to}`); break
+            case "downgrade": println(`  v downgrade  ${a.name} ${a.from} -> ${a.to}`); break
+            case "reinstall": println(`  = reinstall  ${a.name} ${a.version}`); break
+        }
+    })
+}
+
+// ============================================================
+// Remote mirrors
+// ============================================================
+//
+// `mirrors.list` lives next to the installed package manifests.
+// Each non-empty, non-`#` line is the URL prefix of a Hopper mirror.
+// The mirror MUST expose `<prefix>mirror_manifest` (key:value pairs
+// describing the mirror) and `<prefix>filelist` (CSV with rows of
+// `packagename,version,hoppermanifest-filename`).
+//
+// Trailing slash on the prefix is optional and will be added if missing.
+
+function loadMirrorList() {
+    const f = files.open(MIRROR_LIST_PATH)
+    if (!f.exists || f.isDirectory) return []
+    return f.sread().split("\n")
+        .map(line => line.replace(/\r$/, "").trim())
+        .filter(line => line.length > 0 && line[0] !== "#")
+        .map(line => line.endsWith("/") ? line : (line + "/"))
+}
+
+function parseFileList(text) {
+    const out = []
+    text.split("\n").forEach(raw => {
+        const line = raw.replace(/\r$/, "").trim()
+        if (line.length === 0 || line[0] === "#") return
+        const parts = line.split(",")
+        if (parts.length < 3) return
+        out.push({
+            name:    parts[0].trim(),
+            version: parts[1].trim(),
+            file:    parts[2].trim(),
+        })
+    })
+    return out
+}
+
+function fetchManifestsFromMirror(prefix) {
+    const mfText = net.fetchText(prefix + "mirror_manifest")
+    if (mfText === null) {
+        printerrln(`  ! could not reach mirror: ${prefix}`)
+        return []
+    }
+    const mirror = parseManifest(mfText)
+    const mirrorName = mirror.HopperMirrorName || prefix
+
+    const flText = net.fetchText(prefix + "filelist")
+    if (flText === null) {
+        printerrln(`  ! mirror "${mirrorName}" has no filelist`)
+        return []
+    }
+
+    const out = []
+    parseFileList(flText).forEach(entry => {
+        const manifestText = net.fetchText(prefix + entry.file)
+        if (manifestText === null) {
+            printerrln(`  ! mirror "${mirrorName}" missing ${entry.file}`)
+            return
+        }
+        const m = parseManifest(manifestText)
+        m._mirrorName   = mirrorName
+        m._mirrorPrefix = prefix
+        m._manifestUrl  = prefix + entry.file
+        out.push(m)
+    })
+    return out
+}
+
+// Per-invocation memoisation. Search and install both pull the same
+// data; we only want to hit the network once per `hopper ...` call.
+let _remoteCache = null
+
+function fetchRemoteCandidates() {
+    if (_remoteCache !== null) return _remoteCache
+
+    const mirrors = loadMirrorList()
+    if (mirrors.length === 0) {
+        _remoteCache = []
+        return _remoteCache
+    }
+
+    if (!net.isAvailable()) {
+        printerrln("Warning: no HTTP modem attached; remote mirrors will be skipped.")
+        _remoteCache = []
+        return _remoteCache
+    }
+
+    const out = []
+    mirrors.forEach(prefix => {
+        fetchManifestsFromMirror(prefix).forEach(m => out.push(m))
+    })
+    _remoteCache = out
+    return _remoteCache
+}
+
+// ============================================================
+// Search
+// ============================================================
+
+function fieldCandidates(manifest, field) {
+    switch (field) {
+        case "provides":    return splitList(manifest.HopperProvides || "")
+        case "requires":    return splitList(manifest.HopperRequires || "")
+        case "description": return [manifest.ProperDescription || ""]
+        case "author":      return [manifest.ProperAuthor || ""]
+        default:            return [manifest.ProperName || "", manifest.HopperPackageName || ""]
+    }
+}
+
+function matchesQuery(manifest, field, query) {
+    const q = query.toLowerCase()
+    return fieldCandidates(manifest, field).some(c => c.toLowerCase().indexOf(q) >= 0)
+}
+
+function printSearchResult(m, origin) {
+    const name = m.ProperName || m.HopperPackageName || "(unnamed)"
+    const ver  = m.HopperPackageVersion || "?"
+    println(`  [${origin}] ${name} -- ${m.HopperPackageName} ${ver}`)
+    if (m.ProperDescription) println(`           ${m.ProperDescription}`)
+}
+
+function cmdSearch(args) {
+    let field = "name"
+    let query = undefined
+    for (let i = 0; i < args.length; i++) {
+        const a = args[i]
+        if      (a === "--provides")    field = "provides"
+        else if (a === "--requires")    field = "requires"
+        else if (a === "--description") field = "description"
+        else if (a === "--author")      field = "author"
+        else if (a.startsWith("--"))    { printerrln(`Unknown option: ${a}`); return 1 }
+        else                            query = a
+    }
+    if (query === undefined) {
+        printerrln("Usage: hopper search [--provides|--requires|--description|--author] <query>")
+        return 1
+    }
+
+    println(`Searching installed packages in ${SYSTEM_PACKEAGE_DEF_DIR} ...`)
+    const sysHits = listInstalledManifests().filter(m => matchesQuery(m, field, query))
+    if (sysHits.length === 0) println("  (no matches)")
+    else sysHits.forEach(m => printSearchResult(m, "installed"))
+
+    println("")
+    println("Searching remote mirrors ...")
+    const remote = fetchRemoteCandidates()
+    if (remote.length === 0) {
+        println("  (no mirrors configured or reachable)")
+    }
+    else {
+        const netHits = remote.filter(m => matchesQuery(m, field, query))
+        if (netHits.length === 0) println("  (no matches)")
+        else netHits.forEach(m => printSearchResult(m, m._mirrorName || "remote"))
+    }
+
+    return 0
+}
+
+// ============================================================
+// Install
+// ============================================================
+//
+// Each upstream manifest declares its payload via `PackageFileList`,
+// a semicolon-separated list of full URLs. Hopper fetches each URL and
+// drops the result in /hopper/bin (default) or /hopper/include (.mjs).
+// The locally-saved manifest gets a `SystemPackagePath` field appended
+// listing the resulting absolute paths, which is what `cmdRemove` later
+// walks to clean up.
+
+function _installOne(action, candidate) {
+    const m = candidate.manifest
+    const files_ = parsePackageFileList(m.PackageFileList)
+    if (files_.length === 0) {
+        printerrln(`  ! ${candidate.name}: upstream manifest has no PackageFileList; cannot install`)
+        return false
+    }
+
+    // Fetch first, write second: a single 404 should not leave a
+    // half-installed package behind.
+    const fetched = []
+    for (let i = 0; i < files_.length; i++) {
+        const f = files_[i]
+        println(`  fetch  ${f.url}`)
+        const body = net.fetchText(f.url)
+        if (body === null || body === undefined) {
+            printerrln(`  ! failed to fetch ${f.url}`)
+            return false
+        }
+        fetched.push({ entry: f, body: body })
+    }
+
+    // If we are replacing an existing user-installed copy, remove its
+    // old files first so a renamed payload doesn't leave orphans.
+    if (action !== "install") {
+        const oldManifestPath = `${USER_PACKAGE_DEF_DIR}/${candidate.name}.${MANIFEST_EXT}`
+        const old = readManifestFile(oldManifestPath)
+        if (old !== undefined) {
+            splitList(old.SystemPackagePath || "").forEach(p => {
+                expandSystemPath(p).forEach(abs => {
+                    const fd = files.open(abs)
+                    if (fd.exists) {
+                        try { fd.remove() }
+                        catch (e) { printerrln(`  ! could not remove old ${abs}: ${e}`) }
+                    }
+                })
+            })
+        }
+    }
+
+    // Write payload files.
+    fetched.forEach(item => {
+        const fd = files.open(item.entry.localPath)
+        if (!fd.exists) fd.mkFile()
+        fd.swrite(item.body)
+        println(`  write  ${item.entry.localPath}`)
+    })
+
+    // Save the manifest with SystemPackagePath appended.
+    const sysPath = fetched.map(item => declarablePath(item.entry.localPath)).join(";")
+    const manifestPath = `${USER_PACKAGE_DEF_DIR}/${candidate.name}.${MANIFEST_EXT}`
+    const mfd = files.open(manifestPath)
+    if (!mfd.exists) mfd.mkFile()
+    mfd.swrite(serializeManifest(m, sysPath))
+    println(`  write  ${manifestPath}`)
+    return true
+}
+
+function cmdInstall(args) {
+    let query = undefined
+    let version = undefined
+    for (let i = 0; i < args.length; i++) {
+        if (args[i] === "-v") { version = args[i + 1]; i++ }
+        else if (args[i].startsWith("--")) { printerrln(`Unknown option: ${args[i]}`); return 1 }
+        else query = args[i]
+    }
+    if (query === undefined) {
+        printerrln("Usage: hopper install <package> [-v <version>]")
+        return 1
+    }
+
+    const targetConstraint = version || "*"
+    const verSuffix = (targetConstraint !== "*") ? ` (${targetConstraint})` : ""
+    println(`Resolving ${query}${verSuffix} ...`)
+
+    const idx = buildCandidateIndex()
+
+    // Sanity check: target must exist in the index (installed or upstream).
+    if (findProviders(idx, query).length === 0) {
+        printerrln(`Error: package "${query}" not found (not on upstream, not installed).`)
+        return 4
+    }
+
+    // Seed order matters: the target goes FIRST so its (possibly tight)
+    // constraints can drive upgrades of dependencies. The installed-set
+    // requirements follow at "*" so the resolver still has to keep them
+    // alive (preferring installed candidates when their version still fits,
+    // otherwise upgrading or downgrading them).
+    const seed = [{ name: query, constraint: targetConstraint }]
+    listInstalledManifests().forEach(m => {
+        if (m.HopperPackageName === query) return
+        seed.push({ name: m.HopperPackageName, constraint: "*" })
+    })
+
+    const { chosen, issues } = resolveAll(idx, seed)
+    if (issues.length > 0) {
+        printerrln("Resolution failed:")
+        issues.forEach(reason => printerrln(`  - ${reason}`))
+        printerrln("")
+        printerrln("No solution found -- not installable.")
+        return 3
+    }
+
+    const plan = classifyPlan(idx, chosen)
+    printPlan(plan, query)
+
+    const changing = plan.filter(a => a.action !== "keep")
+    if (changing.length === 0) return 0
+
+    // Pre-flight: refuse to clobber system packages, and require every
+    // upstream candidate to actually carry a payload list.
+    const blockers = []
+    changing.forEach(a => {
+        const cand = chosen.get(a.name)
+        const inst = findInstalledManifest(a.name)
+        if (inst && inst._origin === "system") {
+            blockers.push(`${a.name}: cannot ${a.action} -- a system package with that name is already installed`)
+        }
+        if (cand && cand.source === "upstream" && !(cand.manifest.PackageFileList && cand.manifest.PackageFileList.length > 0)) {
+            blockers.push(`${a.name}: upstream manifest declares no PackageFileList`)
+        }
+    })
+    if (blockers.length > 0) {
+        printerrln("Cannot proceed:")
+        blockers.forEach(b => printerrln(`  - ${b}`))
+        return 5
+    }
+
+    if (!net.isAvailable()) {
+        printerrln("No HTTP modem attached; cannot fetch package files.")
+        return 6
+    }
+
+    println("")
+    if (!confirm("Proceed with installation?", true)) {
+        println("Aborted.")
+        return 0
+    }
+
+    ensureUserDirs()
+
+    let failed = 0
+    for (let i = 0; i < changing.length; i++) {
+        const a = changing[i]
+        const cand = chosen.get(a.name)
+        if (a.action === "install" || a.action === "reinstall") {
+            println(`${a.action} ${a.name} ${a.version}`)
+        } else {
+            println(`${a.action} ${a.name} ${a.from} -> ${a.to}`)
+        }
+        if (!_installOne(a.action, cand)) {
+            failed++
+            printerrln(`  ! ${a.name}: aborted`)
+            break
+        }
+    }
+    if (failed > 0) {
+        printerrln(`${failed} package(s) failed to install.`)
+        return 7
+    }
+
+    println("Done.")
+    return 0
+}
+
+// ============================================================
+// Remove
+// ============================================================
+
+// Convert a SystemPackagePath entry (e.g. "/tvdos/bin/taut*") into a
+// concrete list of files on the A: drive. Supports a simple '*' wildcard
+// in the filename component.
+function expandSystemPath(pattern) {
+    const sysDrive = "A:"
+
+    if (pattern.indexOf("*") < 0) {
+        return [`${sysDrive}${pattern}`]
+    }
+
+    const fwd = pattern.lastIndexOf("/")
+    const bck = pattern.lastIndexOf("\\")
+    const lastSep = Math.max(fwd, bck)
+    const dirPart  = (lastSep < 0) ? "" : pattern.substring(0, lastSep)
+    const namePart = (lastSep < 0) ? pattern : pattern.substring(lastSep + 1)
+
+    const dir = files.open(`${sysDrive}${dirPart}/`)
+    if (!dir.exists || !dir.isDirectory) return []
+
+    const escaped = namePart.replace(/[.+^${}()|[\]\\]/g, "\\$&").replace(/\*/g, ".*")
+    const re = new RegExp(`^${escaped}$`, "i")
+
+    const out = []
+    dir.list().forEach(entry => {
+        if (entry.isDirectory) return
+        if (re.test(entry.name)) out.push(entry.fullPath)
+    })
+    return out
+}
+
+function cmdRemove(args) {
+    const query = args[0]
+    if (query === undefined) {
+        printerrln("Usage: hopper remove <package>")
+        return 1
+    }
+
+    const m = findInstalledManifest(query)
+    if (m === undefined) {
+        printerrln(`Package not installed: ${query}`)
+        return 2
+    }
+    if (m._origin === "system") {
+        printerrln(`Cannot remove ${query}: it is a system package.`)
+        return 6
+    }
+
+    const name = m.ProperName || m.HopperPackageName || query
+    const ver  = m.HopperPackageVersion || "?"
+    println(`Preparing removal of ${name} (${m.HopperPackageName} ${ver}) ...`)
+
+    const paths = splitList(m.SystemPackagePath || "")
+    println("")
+    println("The following files will be deleted:")
+    if (paths.length === 0) {
+        println("  (manifest declares no files)")
+    }
+    paths.forEach(p => {
+        const expanded = expandSystemPath(p)
+        if (expanded.length === 0) {
+            println(`  (no match on disk) ${p}`)
+        }
+        else {
+            expanded.forEach(e => println(`  ${e}`))
+        }
+    })
+    println(`  ${m._manifestPath}`)
+
+    println("")
+    if (!confirm("Proceed with removal?", false)) {
+        println("Aborted.")
+        return 0
+    }
+
+    const removed = deleteInstalledFiles(m)
+    removed.forEach(p => println(`  removed ${p}`))
+    if (removed.length === 0) println("  (nothing was removed)")
+    return 0
+}
+
+// ============================================================
+// Dispatch
+// ============================================================
+
+function printUsage() {
+    println("Hopper - Package manager for TVDOS")
+    println("")
+    println("Usage:")
+    println("  hopper {search,se} [--provides|--requires|--description|--author] <query>")
+    println("  hopper {install,in} <package> [-v <version>]")
+    println("  hopper {remove,rm} <package>")
+}
+
+const _hopperArgs = (typeof exec_args !== "undefined" && exec_args) ? exec_args.slice(1) : []
+const _hopperCmd  = _hopperArgs[0]
+const _hopperRest = _hopperArgs.slice(1)
+
+switch (_hopperCmd) {
+    case "search":
+    case "se":
+        return cmdSearch(_hopperRest)
+    case "install":
+    case "in":
+        return cmdInstall(_hopperRest)
+    case "remove":
+    case "rm":
+        return cmdRemove(_hopperRest)
+    case undefined:
+        printUsage()
+        return 0
+    default:
+        printerrln(`Unknown command: ${_hopperCmd}`)
+        printUsage()
+        return 1
+}

assets/disk0/tvdos/bin/lfs.js

@@ -15,7 +15,10 @@ Uint16  Encoding
     10 00 : UTF-8
     10 01 : UTF-16BE
     10 02 : UTF-16LE
-Byte[5] Padding
+Byte    Flags
+    0b 0000 000r
+        r: path is relative
+Bytes[4] Reserved
 
 # FileBlocks
 Uint8    File type (only 1 is used)
@@ -28,27 +31,36 @@ instead of compressing individual files)
 
 function printUsage() {
     println(`Collects files under a directory into a single archive.
-Usage: lfs [-c/-x/-t] dest.lfs path\\to\\source
+Usage: lfs [-c/-x/-t] [-r] dest.lfs path\\to\\source
 To collect a directory into myarchive.lfs:
        lfs -c myarchive.lfs path\\to\\directory
+To collect a directory into myarchive.lfs, using relative path:
+       lfs -c -r myarchive.lfs path\\to\\directory
 To extract an archive to path\\to\\my\\files:
        lfs -x myarchive.lfs path\\to\\my\\files
 To list the collected files:
        lfs -t myarchive.lfs`)
 }
 
-let option = exec_args[1]
-const lfsPath = exec_args[2]
-const dirPath = exec_args[3]
+let option = undefined
+let useRelative = false
+const positional = []
+for (let i = 1; i < exec_args.length; i++) {
+    const a = exec_args[i]
+    if (a === undefined) continue
+    const au = a.toUpperCase()
+    if (au === "-C" || au === "-X" || au === "-T") option = au
+    else if (au === "-R") useRelative = true
+    else positional.push(a)
+}
+const lfsPath = positional[0]
+const dirPath = positional[1]
 
-
-if (option === undefined || lfsPath === undefined || option.toUpperCase() != "-T" && dirPath === undefined) {
+if (option === undefined || lfsPath === undefined || (option != "-T" && dirPath === undefined)) {
     printUsage()
     return 0
 }
 
-option = option.toUpperCase()
-
 
 function recurseDir(file, action) {
     if (!file.isDirectory) {
@@ -76,13 +88,14 @@ if ("-C" == option) {
         return 1
     }
 
-    let out = "TVDOSLFS\x01\x00\x00\x00\x00\x00\x00\x00"
+    const flagsByte = useRelative ? 0x01 : 0x00
+    let out = "TVDOSLFS\x01\x00\x00" + String.fromCharCode(flagsByte) + "\x00\x00\x00\x00"
     const rootDirPathLen = rootDir.fullPath.length
 
     recurseDir(rootDir, file=>{
         let f = files.open(file.fullPath)
         let flen = f.size
-        let fname = file.fullPath.substring(rootDirPathLen + 1)
+        let fname = useRelative ? file.fullPath.substring(rootDirPathLen + 1) : file.fullPath
         let plen = fname.length
 
         out += "\x01" + String.fromCharCode(
@@ -116,6 +129,8 @@ else if ("-T" == option || "-X" == option) {
         return 2
     }
 
+    const archiveRelative = (bytes.charCodeAt(11) & 0x01) !== 0
+
     if ("-X" == option && !rootDir.exists) {
         rootDir.mkDir()
     }
@@ -132,9 +147,12 @@ else if ("-T" == option || "-X" == option) {
 
         if ("-X" == option) {
             let filebytes = bytes.substring(curs, curs + filelen)
-            let outfile = files.open(`${rootDir.fullPath}\\${path}`)
+            // Fully qualified paths (e.g. "A:\foo\bar.txt") get their drive prefix
+            // stripped so the archive contents re-root under the destination dir.
+            let subPath = archiveRelative ? path : path.replace(/^[A-Za-z]:[\\\/]?/, "")
+            let outfile = files.open(`${rootDir.fullPath}\\${subPath}`)
 
-            mkDirs(files.open(`${rootDir.driveLetter}:${files.open(`${rootDir.fullPath}\\${path}`).parentPath}`))
+            mkDirs(files.open(`${outfile.driveLetter}:${outfile.parentPath}`))
             outfile.mkFile()
             outfile.swrite(filebytes)
         }

assets/disk0/tvdos/bin/playmp2.js

@@ -1,209 +1,122 @@
-const SND_BASE_ADDR = audio.getBaseAddr()
+// playmp2 — MPEG-1/2 Audio Layer II player with the shared playgui visualiser.
+// Usage: playmp2 <file.mp2> [-i]
 
+const SND_BASE_ADDR = audio.getBaseAddr()
 if (!SND_BASE_ADDR) return 10
 
-const MP2_BITRATES = ["???", 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384]
+const MP2_BITRATES     = ["???", 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384]
 const MP2_CHANNELMODES = ["Stereo", "Joint", "Dual", "Mono"]
+
 const pcm = require("pcm")
-const interactive = exec_args[2] && exec_args[2].toLowerCase() == "-i"
+const interactive = exec_args[2] && exec_args[2].toLowerCase() === "-i"
+const gui = interactive ? require("playgui") : null
+
 function printdbg(s) { if (0) serial.println(s) }
 
-
 class SequentialFileBuffer {
-
     constructor(path, offset, length) {
         if (Array.isArray(path)) throw Error("arg #1 is path(string), not array")
-
         this.path = path
         this.file = files.open(path)
-
         this.offset = offset || 0
         this.originalOffset = offset
         this.length = length || this.file.size
-
         this.seq = require("seqread")
         this.seq.prepare(path)
     }
-
-    readBytes(size, ptr) {
-        return this.seq.readBytes(size, ptr)
-    }
-
-    readStr(n) {
-        let ptr = this.seq.readBytes(n)
-        let s = ''
-        for (let i = 0; i < n; i++) {
-            if (i >= this.length) break
-            s += String.fromCharCode(sys.peek(ptr + i))
-        }
-        sys.free(ptr)
-        return s
-    }
-
-    unread(diff) {
-        let newSkipLen = this.seq.getReadCount() - diff
-        this.seq.prepare(this.path)
-        this.seq.skip(newSkipLen)
-    }
-
-    rewind() {
-        this.seq.prepare(this.path)
-    }
-
-    seek(p) {
-        this.seq.prepare(this.path)
-        this.seq.skip(p)
-    }
-
-    get byteLength() {
-        return this.length
-    }
-
-    get fileHeader() {
-        return this.seq.fileHeader
-    }
-
-    /*get remaining() {
-        return this.length - this.getReadCount()
-    }*/
+    readBytes(size, ptr) { return this.seq.readBytes(size, ptr) }
+    get fileHeader() { return this.seq.fileHeader }
 }
 
-
-
-
-
-let filebuf = new SequentialFileBuffer(_G.shell.resolvePathInput(exec_args[1]).full)
-const FILE_SIZE = filebuf.length// - 100
-const FRAME_SIZE = audio.mp2GetInitialFrameSize(filebuf.fileHeader)
+const filebuf       = new SequentialFileBuffer(_G.shell.resolvePathInput(exec_args[1]).full)
+const FILE_SIZE     = filebuf.length
+const FRAME_SIZE    = audio.mp2GetInitialFrameSize(filebuf.fileHeader)
 const MEDIA_BITRATE = MP2_BITRATES[filebuf.fileHeader[2] >>> 4]
-const MEDIA_CHANNEL_MODE = MP2_CHANNELMODES[filebuf.fileHeader[3] >>> 6]
+const MEDIA_CHANNEL = MP2_CHANNELMODES[filebuf.fileHeader[3] >>> 6]
 
+// mediaDecodedBin sits at MMIO offset 64 in the audio peripheral and holds
+// 2304 bytes (1152 stereo u8 samples per MP2 frame).  Peripheral memory grows
+// toward 0 so the canonical pointer is SND_BASE_ADDR - 64.
+//
+// IMPORTANT: single-byte sys.peek on this address hits AudioAdapter.peek()
+// which maps the lower offsets to sampleBin, not mediaDecodedBin (the
+// MMIO/Memory-Space split — see CLAUDE.md).  To get the decoded PCM into the
+// visualiser, we sys.memcpy mediaDecodedBin → a RAM scratch buffer; memcpy
+// uses VM.getDev internally which DOES route the MMIO read correctly.
+//
+// VM.getDev's range check on mediaDecodedBin (relPtrInDev) is half-open and
+// won't let us copy the full 2304 bytes — we copy 2302 (one stereo sample
+// short of the frame, invisible at visualiser resolution).
+const MP2_DECODED_ADDR    = SND_BASE_ADDR - 64
+const MP2_VIS_COPY_BYTES  = 2302
+const MP2_VIS_SAMPLE_COUNT = MP2_VIS_COPY_BYTES >> 1   // 1151
+const mp2VisScratch = interactive ? sys.malloc(MP2_VIS_COPY_BYTES) : 0
 
-let bytes_left = FILE_SIZE
+let bytes_left    = FILE_SIZE
 let decodedLength = 0
 
-
-//serial.println(`Frame size: ${FRAME_SIZE}`)
-
-
-con.curs_set(0)
-let [__, CONSOLE_WIDTH] = con.getmaxyx()
-if (interactive) {
-    let [cy, cx] = con.getyx()
-    // file name
-    con.mvaddch(cy, 1)
-    con.prnch(0xC9);con.prnch(0xCD);con.prnch(0xB5)
-    print(filebuf.file.name)
-    con.prnch(0xC6);con.prnch(0xCD)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 26 - filebuf.file.name.length))
-    con.prnch(0xB5)
-    print("Hold Bksp to Exit")
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBB)
-
-    // L R pillar
-    con.prnch(0xBA)
-    con.mvaddch(cy+1, CONSOLE_WIDTH, 0xBA)
-
-    // media info
-    let mediaInfoStr = `MP2 ${MEDIA_CHANNEL_MODE} ${MEDIA_BITRATE}kbps`
-    con.move(cy+2,1)
-    con.prnch(0xC8)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 5 - mediaInfoStr.length))
-    con.prnch(0xB5)
-    print(mediaInfoStr)
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBC)
-
-    con.move(cy+1, 2)
-}
-let [cy, cx] = con.getyx()
-let paintWidth = CONSOLE_WIDTH - 20
-function bytesToSec(i) {
-    // using fixed value: FRAME_SIZE(216) bytes for 36 ms on sampling rate 32000 Hz
-    return i / (FRAME_SIZE * 1000 / bufRealTimeLen)
-}
-function secToReadable(n) {
-    let mins = ''+((n/60)|0)
-    let secs = ''+(n % 60)
-    return `${mins.padStart(2,'0')}:${secs.padStart(2,'0')}`
-}
-function printPlayBar(currently) {
-    if (interactive) {
-        let currently = decodedLength
-        let total = FILE_SIZE
-
-        let currentlySec = Math.round(bytesToSec(currently))
-        let totalSec = Math.round(bytesToSec(total))
-
-        con.move(cy, 3)
-        print(' '.repeat(15))
-        con.move(cy, 3)
-
-        print(`${secToReadable(currentlySec)} / ${secToReadable(totalSec)}`)
-
-        con.move(cy, 17)
-        print(' ')
-        let progressbar = '\x84196u'.repeat(paintWidth + 1)
-        print(progressbar)
-
-        con.mvaddch(cy, 18 + Math.round(paintWidth * (currently / total)), 0xDB)
-    }
-}
-
-
+const bufRealTimeLen = 36   // one MP2 frame at 32 kHz ≈ 36 ms
 
 audio.resetParams(0)
 audio.purgeQueue(0)
 audio.setPcmMode(0)
-audio.setPcmQueueCapacityIndex(0, 2) // queue size is now 8
+audio.setPcmQueueCapacityIndex(0, 2)
 const QUEUE_MAX = audio.getPcmQueueCapacity(0)
 audio.setMasterVolume(0, 255)
 audio.play(0)
-
-
-//let mp2context = audio.mp2Init()
 audio.mp2Init()
 
-// decode frame
-let t1 = sys.nanoTime()
-let bufRealTimeLen = 36
+function bytesToSec(i) { return i / (FRAME_SIZE * 1000 / bufRealTimeLen) }
+
+if (interactive) {
+    const tag   = "MP2"
+    const title = `${filebuf.file.name}  ${MEDIA_CHANNEL} ${MEDIA_BITRATE}kbps`
+    gui.audioInit({ title, tag })
+}
+
 let stopPlay = false
 let errorlevel = 0
 try {
     while (bytes_left > 0 && !stopPlay) {
-
-        if (interactive) {
-            sys.poke(-40, 1)
-            if (sys.peek(-41) == 67) {
-                stopPlay = true
-            }
-        }
-
-        printPlayBar()
-
+        if (interactive && gui.audioIsExitRequested()) { stopPlay = true; break }
 
         filebuf.readBytes(FRAME_SIZE, SND_BASE_ADDR - 2368)
         audio.mp2Decode()
 
+        // After decode, 1152 PCMu8 stereo samples sit in mediaDecodedBin
+        // (MMIO).  Bounce them through RAM so single-byte peek in the
+        // visualiser pipeline can reach them — see MP2_DECODED_ADDR notes.
+        if (interactive) {
+            sys.memcpy(MP2_DECODED_ADDR, mp2VisScratch, MP2_VIS_COPY_BYTES)
+            gui.audioFeedPcm(mp2VisScratch, MP2_VIS_SAMPLE_COUNT)
+        }
+
         if (audio.getPosition(0) >= QUEUE_MAX) {
             while (audio.getPosition(0) >= (QUEUE_MAX >>> 1)) {
-                printdbg(`Queue full, waiting until the queue has some space (${audio.getPosition(0)}/${QUEUE_MAX})`)
+                if (interactive) gui.audioRender()
                 sys.sleep(bufRealTimeLen)
             }
         }
         audio.mp2UploadDecoded(0)
+
+        if (interactive) {
+            gui.audioSetProgress(decodedLength / FILE_SIZE,
+                                 bytesToSec(decodedLength), bytesToSec(FILE_SIZE))
+            gui.audioRender()
+        }
         sys.sleep(10)
 
-
-
-        bytes_left -= FRAME_SIZE
+        bytes_left    -= FRAME_SIZE
         decodedLength += FRAME_SIZE
     }
-}
-catch (e) {
+} catch (e) {
     printerrln(e)
     errorlevel = 1
-}
-finally {
+} finally {
+    if (interactive) {
+        if (mp2VisScratch) sys.free(mp2VisScratch)
+        gui.audioClose()
+    }
 }
 
-return errorlevel
+return errorlevel

assets/disk0/tvdos/bin/playpcm.js

@@ -1,196 +1,81 @@
-// usage: playpcm audiofile.pcm [/i]
-let fileeeee = files.open(_G.shell.resolvePathInput(exec_args[1]).full)
-let filename = fileeeee.fullPath
-function printdbg(s) { if (0) serial.println(s) }
+// playpcm — raw PCMu8 stereo player with the shared playgui visualiser.
+// Usage: playpcm <file.pcm> [-i]
 
-const interactive = exec_args[2] && exec_args[2].toLowerCase() == "-i"
-const pcm = require("pcm")
-const FILE_SIZE = files.open(filename).size
-
-
-
-function printComments() {
-    for (const [key, value] of Object.entries(comments)) {
-        printdbg(`${key}: ${value}`)
-    }
-}
-
-function GCD(a, b) {
-    a = Math.abs(a)
-    b = Math.abs(b)
-    if (b > a) {var temp = a; a = b; b = temp}
-    while (true) {
-        if (b == 0) return a
-        a %= b
-        if (a == 0) return b
-        b %= a
-    }
-}
-
-function LCM(a, b) {
-    return (!a || !b) ? 0 : Math.abs((a * b) / GCD(a, b))
-}
-
-
-
-//println("Reading...")
-//serial.println("!!! READING")
+const fileHandle = files.open(_G.shell.resolvePathInput(exec_args[1]).full)
+const filePath   = fileHandle.fullPath
 
+const interactive = exec_args[2] && exec_args[2].toLowerCase() === "-i"
+const pcm     = require("pcm")
 const seqread = require("seqread")
-seqread.prepare(filename)
-
-
-
-
+const gui     = interactive ? require("playgui") : null
 
+const FILE_SIZE = files.open(filePath).size
 
 let BLOCK_SIZE = 4096
-let INFILE_BLOCK_SIZE = BLOCK_SIZE
-const QUEUE_MAX = 8 // according to the spec
+const INFILE_BLOCK_SIZE = BLOCK_SIZE
+const QUEUE_MAX = 8
 
-let nChannels = 2
-let samplingRate = pcm.HW_SAMPLING_RATE;
-let blockSize = 2;
-let bitsPerSample = 8;
-let byterate = 2*samplingRate;
-let comments = {};
-let readPtr = undefined
-let decodePtr = undefined
+const samplingRate = pcm.HW_SAMPLING_RATE
+const byterate     = 2 * samplingRate
 
-function bytesToSec(i) {
-    return i / byterate
-}
-function secToReadable(n) {
-    let mins = ''+((n/60)|0)
-    let secs = ''+(n % 60)
-    return `${mins.padStart(2,'0')}:${secs.padStart(2,'0')}`
-}
-
-let stopPlay = false
-con.curs_set(0)
-let [__, CONSOLE_WIDTH] = con.getmaxyx()
-if (interactive) {
-    let [cy, cx] = con.getyx()
-    // file name
-    con.mvaddch(cy, 1)
-    con.prnch(0xC9);con.prnch(0xCD);con.prnch(0xB5)
-    print(fileeeee.name)
-    con.prnch(0xC6);con.prnch(0xCD)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 26 - fileeeee.name.length))
-    con.prnch(0xB5)
-    print("Hold Bksp to Exit")
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBB)
-
-    // L R pillar
-    con.prnch(0xBA)
-    con.mvaddch(cy+1, CONSOLE_WIDTH, 0xBA)
-
-    // media info
-    let mediaInfoStr = `Raw PCM 512kbps`
-    con.move(cy+2,1)
-    con.prnch(0xC8)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 5 - mediaInfoStr.length))
-    con.prnch(0xB5)
-    print(mediaInfoStr)
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBC)
-
-    con.move(cy+1, 2)
-}
-let [cy, cx] = con.getyx()
-let paintWidth = CONSOLE_WIDTH - 20
-// read chunks loop
-readPtr = sys.malloc(BLOCK_SIZE * bitsPerSample / 8)
-decodePtr = sys.malloc(BLOCK_SIZE * pcm.HW_SAMPLING_RATE / samplingRate)
+function bytesToSec(i) { return i / byterate }
 
+seqread.prepare(filePath)
 
+const readPtr = sys.malloc(BLOCK_SIZE)
 audio.resetParams(0)
 audio.purgeQueue(0)
 audio.setPcmMode(0)
 audio.setMasterVolume(0, 255)
 
-let readLength = 1
-
-function printPlayBar() {
-    if (interactive) {
-        let currently = seqread.getReadCount()
-        let total = FILE_SIZE
-
-        let currentlySec = Math.round(bytesToSec(currently))
-        let totalSec = Math.round(bytesToSec(total))
-
-        con.move(cy, 3)
-        print(' '.repeat(15))
-        con.move(cy, 3)
-
-        print(`${secToReadable(currentlySec)} / ${secToReadable(totalSec)}`)
-
-        con.move(cy, 17)
-        print(' ')
-        let progressbar = '\x84196u'.repeat(paintWidth + 1)
-        print(progressbar)
-
-        con.mvaddch(cy, 18 + Math.round(paintWidth * (currently / total)), 0xDB)
-    }
+if (interactive) {
+    gui.audioInit({
+        title: `${fileHandle.name}  Raw PCM 32kHz Stereo`,
+        tag: "PCM"
+    })
 }
+
+let stopPlay = false
 let errorlevel = 0
+let readLength = 1
 try {
-while (!stopPlay && seqread.getReadCount() < FILE_SIZE && readLength > 0) {
-    if (interactive) {
-        sys.poke(-40, 1)
-        if (sys.peek(-41) == 67) {
-            stopPlay = true
-        }
-    }
+    while (!stopPlay && seqread.getReadCount() < FILE_SIZE && readLength > 0) {
+        if (interactive && gui.audioIsExitRequested()) { stopPlay = true; break }
 
+        const queueSize = audio.getPosition(0)
+        if (queueSize <= 1) {
+            for (let repeat = QUEUE_MAX - queueSize; repeat > 0; repeat--) {
+                const remainingBytes = FILE_SIZE - seqread.getReadCount()
+                readLength = (remainingBytes < INFILE_BLOCK_SIZE) ? remainingBytes : INFILE_BLOCK_SIZE
+                if (readLength <= 0) break
 
-    let queueSize = audio.getPosition(0)
-    if (queueSize <= 1) {
+                seqread.readBytes(readLength, readPtr)
 
-        printPlayBar()
+                // Raw PCMu8 stereo — sampleCount = bytes / 2.
+                if (interactive) gui.audioFeedPcm(readPtr, readLength >> 1)
 
-        // upload four samples for lag-safely
-        for (let repeat = QUEUE_MAX - queueSize; repeat > 0; repeat--) {
-            let remainingBytes = FILE_SIZE - seqread.getReadCount()
+                audio.putPcmDataByPtr(0, readPtr, readLength, 0)
+                audio.setSampleUploadLength(0, readLength)
+                audio.startSampleUpload(0)
 
-            readLength = (remainingBytes < INFILE_BLOCK_SIZE) ? remainingBytes : INFILE_BLOCK_SIZE
-            if (readLength <= 0) {
-                printdbg(`readLength = ${readLength}`)
-                break
+                if (repeat > 1) sys.sleep(10)
             }
-
-            printdbg(`offset: ${seqread.getReadCount()}/${FILE_SIZE}; readLength: ${readLength}`)
-
-            seqread.readBytes(readLength, readPtr)
-
-            audio.putPcmDataByPtr(0, readPtr, readLength, 0)
-            audio.setSampleUploadLength(0, readLength)
-            audio.startSampleUpload(0)
-
-
-            if (repeat > 1) sys.sleep(10)
-
-            printPlayBar()
+            audio.play(0)
         }
 
-        audio.play(0)
+        if (interactive) {
+            const cur = seqread.getReadCount()
+            gui.audioSetProgress(cur / FILE_SIZE, bytesToSec(cur), bytesToSec(FILE_SIZE))
+            gui.audioRender()
+        }
+        sys.sleep(10)
     }
-
-    let remainingBytes = FILE_SIZE - seqread.getReadCount()
-    printdbg(`readLength = ${readLength}; remainingBytes2 = ${remainingBytes}; seqread.getReadCount() = ${seqread.getReadCount()};`)
-
-
-    sys.sleep(10)
-}
-}
-catch (e) {
+} catch (e) {
     printerrln(e)
     errorlevel = 1
-}
-finally {
-    //audio.stop(0)
+} finally {
     if (readPtr !== undefined) sys.free(readPtr)
-    if (decodePtr !== undefined) sys.free(decodePtr)
+    if (interactive) gui.audioClose()
 }
 
 return errorlevel
-

assets/disk0/tvdos/bin/playtad.js

@@ -1,114 +1,66 @@
+// playtad — TAD (TSVM Advanced Audio) player with the shared playgui visualiser.
+// Usage: playtad <file.tad> [-i | -d]
+//   -i   Interactive mode (visualiser + progress bar; hold Backspace to exit)
+//   -d   Dump mode (print the first three chunks to serial for debugging)
+
 const SND_BASE_ADDR = audio.getBaseAddr()
-const SND_MEM_ADDR = audio.getMemAddr()
-// tadInputBin lives at audio-local offset 917504 and tadDecodedBin at 983040
-// (post-bef85f6 memory map; the old 262144 offset now hits the enlarged sampleBin).
-const TAD_INPUT_ADDR = SND_MEM_ADDR - 917504  // TAD input buffer (matches TAV packet 0x24)
-const TAD_DECODED_ADDR = SND_MEM_ADDR - 983040  // TAD decoded buffer
+const SND_MEM_ADDR  = audio.getMemAddr()
+// tadInputBin at offset 917504, tadDecodedBin at 983040.  Both addressed via
+// negative pointers — peripheral memory grows toward 0.
+const TAD_INPUT_ADDR   = SND_MEM_ADDR - 917504
+const TAD_DECODED_ADDR = SND_MEM_ADDR - 983040
 
 if (!SND_BASE_ADDR) return 10
 
-// Check for help flag or missing arguments
-if (!exec_args[1] || exec_args[1] == "-h" || exec_args[1] == "--help") {
-    serial.println("Usage: playtad <file.tad> [-i | -d] [quality]")
-    serial.println("  -i         Interactive mode (progress bar, press Backspace to exit)")
-    serial.println("  -d         Dump mode (show first 3 chunks with payload hex and decoded samples)")
-    serial.println("")
-    serial.println("Examples:")
-    serial.println("  playtad audio.tad -i        # Play with progress bar")
-    serial.println("  playtad audio.tad -d        # Dump first 3 chunks for debugging")
+if (!exec_args[1] || exec_args[1] === "-h" || exec_args[1] === "--help") {
+    serial.println("Usage: playtad <file.tad> [-i | -d]")
+    serial.println("  -i  Interactive mode (visualiser + progress bar)")
+    serial.println("  -d  Dump first three chunks for debugging")
     return 0
 }
 
-const pcm = require("pcm")
-const interactive = exec_args[2] && exec_args[2].toLowerCase() == "-i"
-const dumpCoeffs = exec_args[2] && exec_args[2].toLowerCase() == "-d"
-
-function printdbg(s) { if (0) serial.println(s) }
-
+const interactive = exec_args[2] && exec_args[2].toLowerCase() === "-i"
+const dumpCoeffs  = exec_args[2] && exec_args[2].toLowerCase() === "-d"
+const gui = interactive ? require("playgui") : null
 
 class SequentialFileBuffer {
-
-    constructor(path, offset, length) {
+    constructor(path) {
         if (Array.isArray(path)) throw Error("arg #1 is path(string), not array")
-
         this.path = path
         this.file = files.open(path)
-
-        this.offset = offset || 0
-        this.originalOffset = offset
-        this.length = length || this.file.size
-
+        this.length = this.file.size
         this.seq = require("seqread")
         this.seq.prepare(path)
     }
-
-    readBytes(size, ptr) {
-        return this.seq.readBytes(size, ptr)
-    }
-
+    readBytes(size, ptr) { return this.seq.readBytes(size, ptr) }
     readByte() {
-        let ptr = this.seq.readBytes(1)
-        let val = sys.peek(ptr)
+        const ptr = this.seq.readBytes(1)
+        const val = sys.peek(ptr)
         sys.free(ptr)
         return val
     }
-
     readShort() {
-        let ptr = this.seq.readBytes(2)
-        let val = sys.peek(ptr) | (sys.peek(ptr + 1) << 8)
+        const ptr = this.seq.readBytes(2)
+        const val = sys.peek(ptr) | (sys.peek(ptr + 1) << 8)
         sys.free(ptr)
         return val
     }
-
     readInt() {
-        let ptr = this.seq.readBytes(4)
-        let val = sys.peek(ptr) | (sys.peek(ptr + 1) << 8) | (sys.peek(ptr + 2) << 16) | (sys.peek(ptr + 3) << 24)
+        const ptr = this.seq.readBytes(4)
+        const val = sys.peek(ptr) | (sys.peek(ptr + 1) << 8) | (sys.peek(ptr + 2) << 16) | (sys.peek(ptr + 3) << 24)
         sys.free(ptr)
         return val
     }
-
-    readStr(n) {
-        let ptr = this.seq.readBytes(n)
-        let s = ''
-        for (let i = 0; i < n; i++) {
-            if (i >= this.length) break
-            s += String.fromCharCode(sys.peek(ptr + i))
-        }
-        sys.free(ptr)
-        return s
-    }
-
     unread(diff) {
-        let newSkipLen = this.seq.getReadCount() - diff
+        const newSkipLen = this.seq.getReadCount() - diff
         this.seq.prepare(this.path)
         this.seq.skip(newSkipLen)
     }
-
-    rewind() {
-        this.seq.prepare(this.path)
-    }
-
-    seek(p) {
-        this.seq.prepare(this.path)
-        this.seq.skip(p)
-    }
-
-    get byteLength() {
-        return this.length
-    }
-
-    get fileHeader() {
-        return this.seq.fileHeader
-    }
-
-    getReadCount() {
-        return this.seq.getReadCount()
-    }
+    rewind() { this.seq.prepare(this.path) }
+    getReadCount() { return this.seq.getReadCount() }
 }
 
-
-// Read TAD chunk header to determine format
-let filebuf = new SequentialFileBuffer(_G.shell.resolvePathInput(exec_args[1]).full)
+const filebuf   = new SequentialFileBuffer(_G.shell.resolvePathInput(exec_args[1]).full)
 const FILE_SIZE = filebuf.length
 
 if (FILE_SIZE < 7) {
@@ -116,12 +68,12 @@ if (FILE_SIZE < 7) {
     return 1
 }
 
-// Read first chunk header (standalone TAD format: no TAV wrapper)
-let firstSampleCount = filebuf.readShort()
-let firstMaxIndex = filebuf.readByte()
-let firstPayloadSize = filebuf.readInt()
+// Peek the first chunk header so we know the chunk size for the rough bytes-
+// to-seconds conversion shown in the progress bar.
+const firstSampleCount = filebuf.readShort()
+const firstMaxIndex    = filebuf.readByte()
+const firstPayloadSize = filebuf.readInt()
 
-// Validate first chunk
 if (firstSampleCount < 0 || firstSampleCount > 65536) {
     serial.println(`ERROR: Invalid sample count ${firstSampleCount}. File may be corrupted.`)
     return 1
@@ -135,148 +87,68 @@ if (firstPayloadSize < 1 || firstPayloadSize > 65536) {
     return 1
 }
 
-// Rewind to start
 filebuf.rewind()
 
-// Calculate approximate frame info
-const AVG_CHUNK_SIZE = 7 + firstPayloadSize  // TAD header (2+1+4) + payload
-const SAMPLE_RATE = 32000
-const bufRealTimeLen = Math.floor((firstSampleCount / SAMPLE_RATE) * 1000)  // milliseconds per chunk
+const AVG_CHUNK_SIZE = 7 + firstPayloadSize
+const SAMPLE_RATE    = 32000
+const bufRealTimeLen = Math.floor((firstSampleCount / SAMPLE_RATE) * 1000)
 
 if (dumpCoeffs) {
     serial.println(`TAD Coefficient Dump Mode`)
     serial.println(`File: ${filebuf.file.name}`)
-    serial.println(`First chunk header:`)
-    serial.println(`  Sample Count: ${firstSampleCount}`)
-    serial.println(`  Max Index: ${firstMaxIndex}`)
-    serial.println(`  Payload Size: ${firstPayloadSize} bytes`)
+    serial.println(`First chunk: ${firstSampleCount} samples, Q${firstMaxIndex}, ${firstPayloadSize} bytes payload`)
     serial.println(`Chunk Duration: ${bufRealTimeLen} ms`)
     serial.println(``)
 }
 
-
-let bytes_left = FILE_SIZE
+let bytes_left    = FILE_SIZE
 let decodedLength = 0
-let chunkNumber = 0
-
-
-con.curs_set(0)
-let [__, CONSOLE_WIDTH] = con.getmaxyx()
-if (interactive) {
-    let [cy, cx] = con.getyx()
-    // file name
-    con.mvaddch(cy, 1)
-    con.prnch(0xC9);con.prnch(0xCD);con.prnch(0xB5)
-    print(filebuf.file.name)
-    con.prnch(0xC6);con.prnch(0xCD)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 26 - filebuf.file.name.length))
-    con.prnch(0xB5)
-    print("Hold Bksp to Exit")
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBB)
-
-    // L R pillar
-    con.prnch(0xBA)
-    con.mvaddch(cy+1, CONSOLE_WIDTH, 0xBA)
-
-    // media info
-    let mediaInfoStr = `TAD Q${firstMaxIndex} ${SAMPLE_RATE/1000}kHz`
-    con.move(cy+2,1)
-    con.prnch(0xC8)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 5 - mediaInfoStr.length))
-    con.prnch(0xB5)
-    print(mediaInfoStr)
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBC)
-
-    con.move(cy+1, 2)
-}
-let [cy, cx] = con.getyx()
-let paintWidth = CONSOLE_WIDTH - 20
+let chunkNumber   = 0
 
 function bytesToSec(i) {
-    // Approximate: use first chunk's ratio
     return Math.round((i / FILE_SIZE) * (FILE_SIZE / AVG_CHUNK_SIZE) * (bufRealTimeLen / 1000))
 }
 
-function secToReadable(n) {
-    let mins = ''+((n/60)|0)
-    let secs = ''+(n % 60)
-    return `${mins.padStart(2,'0')}:${secs.padStart(2,'0')}`
-}
-
-function printPlayBar() {
-    if (interactive) {
-        let currently = decodedLength
-        let total = FILE_SIZE
-
-        let currentlySec = bytesToSec(currently)
-        let totalSec = bytesToSec(total)
-
-        con.move(cy, 3)
-        print(' '.repeat(15))
-        con.move(cy, 3)
-
-        print(`${secToReadable(currentlySec)} / ${secToReadable(totalSec)}`)
-
-        con.move(cy, 17)
-        print(' ')
-        let progressbar = '\x84196u'.repeat(paintWidth + 1)
-        print(progressbar)
-
-        con.mvaddch(cy, 18 + Math.round(paintWidth * (currently / total)), 0xDB)
-    }
-}
-
-
 audio.resetParams(0)
 audio.purgeQueue(0)
 audio.setPcmMode(0)
-audio.setPcmQueueCapacityIndex(0, 2) // queue size is now 8
+audio.setPcmQueueCapacityIndex(0, 2)
 const QUEUE_MAX = audio.getPcmQueueCapacity(0)
 audio.setMasterVolume(0, 255)
 audio.play(0)
 
+if (interactive) {
+    gui.audioInit({
+        title: `${filebuf.file.name}  TAD Q${firstMaxIndex} ${SAMPLE_RATE/1000}kHz`,
+        tag: "TAD"
+    })
+}
 
 let stopPlay = false
 let errorlevel = 0
-
 try {
     while (bytes_left > 0 && !stopPlay) {
+        if (interactive && gui.audioIsExitRequested()) { stopPlay = true; break }
 
-        if (interactive) {
-            sys.poke(-40, 1)
-            if (sys.peek(-41) == 67) {  // Backspace key
-                stopPlay = true
-            }
-        }
+        const sampleCount = filebuf.readShort()
+        const maxIndex    = filebuf.readByte()
+        const payloadSize = filebuf.readInt()
 
-        printPlayBar()
-
-        // Read TAD chunk header (standalone TAD format)
-        // Format: [sample_count][max_index][payload_size][payload]
-        let sampleCount = filebuf.readShort()
-        let maxIndex = filebuf.readByte()
-        let payloadSize = filebuf.readInt()
-
-        // Validate every chunk (not just first one)
         if (sampleCount < 0 || sampleCount > 65536) {
-            serial.println(`ERROR: Chunk ${chunkNumber}: Invalid sample count ${sampleCount}. File may be corrupted.`)
-            errorlevel = 1
-            break
+            serial.println(`ERROR: Chunk ${chunkNumber}: Invalid sample count ${sampleCount}.`)
+            errorlevel = 1; break
         }
         if (maxIndex < 0 || maxIndex > 255) {
-            serial.println(`ERROR: Chunk ${chunkNumber}: Invalid max index ${maxIndex}. File may be corrupted.`)
-            errorlevel = 1
-            break
+            serial.println(`ERROR: Chunk ${chunkNumber}: Invalid max index ${maxIndex}.`)
+            errorlevel = 1; break
         }
         if (payloadSize < 1 || payloadSize > 65536) {
-            serial.println(`ERROR: Chunk ${chunkNumber}: Invalid payload size ${payloadSize}. File may be corrupted.`)
-            errorlevel = 1
-            break
+            serial.println(`ERROR: Chunk ${chunkNumber}: Invalid payload size ${payloadSize}.`)
+            errorlevel = 1; break
         }
         if (payloadSize + 7 > bytes_left) {
-            serial.println(`ERROR: Chunk ${chunkNumber}: Chunk size ${payloadSize + 7} exceeds remaining file size ${bytes_left}`)
-            errorlevel = 1
-            break
+            serial.println(`ERROR: Chunk ${chunkNumber}: Chunk size exceeds remaining file size.`)
+            errorlevel = 1; break
         }
 
         if (dumpCoeffs && chunkNumber < 3) {
@@ -284,80 +156,59 @@ try {
             serial.println(`  Sample Count: ${sampleCount}`)
             serial.println(`  Max Index: ${maxIndex}`)
             serial.println(`  Payload Size: ${payloadSize} bytes`)
-            serial.println(`  Bytes remaining in file: ${bytes_left}`)
         }
 
-        // Rewind 7 bytes to re-read the header along with payload
-        // This allows reading the complete chunk (header + payload) in one call
+        // Read entire chunk (header + payload) into TAD input buffer.
         filebuf.unread(7)
+        filebuf.readBytes(7 + payloadSize, TAD_INPUT_ADDR)
 
-        // Read entire chunk (header + payload) to TAD input buffer
-        // This matches TAV's approach for packet 0x24
-        let totalChunkSize = 7 + payloadSize
-        filebuf.readBytes(totalChunkSize, TAD_INPUT_ADDR)
-
-        if (dumpCoeffs && chunkNumber < 3) {
-            // Dump first 32 bytes of compressed payload (skip 7-byte header)
-            serial.print(`  Compressed data (first 32 bytes): `)
-            for (let i = 0; i < Math.min(32, payloadSize); i++) {
-                let b = sys.peek(TAD_INPUT_ADDR + 7 + i)
-                serial.print(`${(b & 0xFF).toString(16).padStart(2, '0')} `)
-            }
-            serial.println('')
-        }
-
-        // Decode TAD chunk
         audio.tadDecode()
-
-        if (dumpCoeffs && chunkNumber < 3) {
-            // After decoding, the decoded PCMu8 samples are in tadDecodedBin
-            serial.println(`  Decoded ${sampleCount} samples`)
-
-            // Dump first 16 decoded samples (PCMu8 stereo interleaved)
-            serial.print(`  Decoded (first 16 L samples): `)
-            for (let i = 0; i < 16; i++) {
-                serial.print(`${sys.peek(TAD_DECODED_ADDR + i * 2) & 0xFF} `)
-            }
-            serial.println('')
-            serial.print(`  Decoded (first 16 R samples): `)
-            for (let i = 0; i < 16; i++) {
-                serial.print(`${sys.peek(TAD_DECODED_ADDR + i * 2 + 1) & 0xFF} `)
-            }
-            serial.println('')
-            serial.println('')
-        }
-
-        // Upload decoded audio to queue
         audio.tadUploadDecoded(0, sampleCount)
+        // After upload tadDecodedBin still holds the chunk until the next
+        // tadDecode call, so it's safe to keep slicing samples out of it
+        // during the playback wait below.
 
         if (!dumpCoeffs) {
-            // Sleep for the duration of the audio chunk to pace playback
-            // This prevents uploading everything at once
-            sys.sleep(bufRealTimeLen)
+            // TAD chunks are typically 1 s long, so feeding the visualiser
+            // once would freeze it for ~1 s.  Walk the chunk in 2048-sample
+            // slices (~64 ms each at 32 kHz) so the wavescope and XY-scope
+            // stay in step with what the audio engine is actually playing.
+            const chunkMs       = Math.floor((sampleCount / SAMPLE_RATE) * 1000)
+            const TAD_VIS_SLICE = 2048
+            if (interactive) {
+                gui.audioSetProgress(decodedLength / FILE_SIZE,
+                                     bytesToSec(decodedLength), bytesToSec(FILE_SIZE))
+                let sliceOff = 0
+                while (sliceOff < sampleCount && !stopPlay) {
+                    if (gui.audioIsExitRequested()) { stopPlay = true; break }
+                    const sliceN = Math.min(TAD_VIS_SLICE, sampleCount - sliceOff)
+                    // tadDecodedBin is negative-addressed: sample i sits at
+                    // TAD_DECODED_ADDR - i*2.  audioFeedPcm flips the read
+                    // direction for negative ptrs internally.
+                    gui.audioFeedPcm(TAD_DECODED_ADDR - sliceOff * 2, sliceN)
+                    gui.audioRender()
+                    sys.sleep(Math.floor((sliceN / SAMPLE_RATE) * 1000))
+                    sliceOff += sliceN
+                }
+            } else {
+                sys.sleep(chunkMs)
+            }
         }
 
-        // Chunk size = header (7 bytes) + payload
-        let chunkSize = 7 + payloadSize
-        bytes_left -= chunkSize
+        const chunkSize = 7 + payloadSize
+        bytes_left    -= chunkSize
         decodedLength += chunkSize
         chunkNumber++
 
-        // Limit coefficient dump to first 3 chunks
         if (dumpCoeffs && chunkNumber >= 3) {
             serial.println(`... (remaining chunks omitted)`)
-            // Keep playing but don't dump more
         }
     }
-}
-catch (e) {
+} catch (e) {
     printerrln(e)
     errorlevel = 1
-}
-finally {
-    if (interactive) {
-        con.move(cy + 3, 1)
-        con.curs_set(1)
-    }
+} finally {
+    if (interactive) gui.audioClose()
 }
 
 return errorlevel

assets/disk0/tvdos/bin/playucf.js

@@ -307,7 +307,7 @@ for (let i = 0; i < cueElements.length; i++) {
             // Execute the player with modified environment
             exec_args[1] = targetPath
             if (playerFile) {
-                let playerPath = `A:\\tvdos\\bin\\${playerFile}.js`
+                let playerPath = `A:${_TVDOS.variables.DOSDIR}/bin/${playerFile}.js`
                 if (files.open(playerPath).exists) {
                     eval(files.readText(playerPath))
                 } else {
@@ -334,7 +334,7 @@ for (let i = 0; i < cueElements.length; i++) {
     }
 
     // Execute the appropriate player
-    let playerPath = `A:\\tvdos\\bin\\${playerFile}.js`
+    let playerPath = `A:${_TVDOS.variables.DOSDIR}/bin/${playerFile}.js`
     if (!files.open(playerPath).exists) {
         serial.println(`Warning: Player script not found: ${playerPath}`)
         continue

assets/disk0/tvdos/bin/playwav.js

@@ -1,329 +1,189 @@
-// usage: playwav audiofile.wav [/i]
-let fileeeee = files.open(_G.shell.resolvePathInput(exec_args[1]).full)
-let filename = fileeeee.fullPath
+// playwav — WAV (LPCM/ADPCM) player with the shared playgui visualiser.
+// Usage: playwav <file.wav> [-i]
+
+const fileHandle = files.open(_G.shell.resolvePathInput(exec_args[1]).full)
+const filePath   = fileHandle.fullPath
+
+const WAV_FORMATS  = ["LPCM", "ADPCM"]
+const WAV_CHANNELS = ["Mono", "Stereo", "3ch", "Quad", "4.1", "5.1", "6.1", "7.1"]
+const interactive  = exec_args[2] && exec_args[2].toLowerCase() === "-i"
+
+const seqread = require("seqread")
+const pcm     = require("pcm")
+const gui     = interactive ? require("playgui") : null
+
 function printdbg(s) { if (0) serial.println(s) }
 
-const WAV_FORMATS = ["LPCM", "ADPCM"]
-const WAV_CHANNELS = ["Mono", "Stereo", "3ch", "Quad", "4.1", "5.1", "6.1", "7.1"]
-const interactive = exec_args[2] && exec_args[2].toLowerCase() == "-i"
-const seqread = require("seqread")
-const pcm = require("pcm")
-
-
-
-function printComments() {
-    for (const [key, value] of Object.entries(comments)) {
-        printdbg(`Wave Comment ${key}: ${value}`)
-    }
-}
-
 function GCD(a, b) {
-    a = Math.abs(a)
-    b = Math.abs(b)
-    if (b > a) {var temp = a; a = b; b = temp}
+    a = Math.abs(a); b = Math.abs(b)
+    if (b > a) { const t = a; a = b; b = t }
     while (true) {
-        if (b == 0) return a
+        if (b === 0) return a
         a %= b
-        if (a == 0) return b
+        if (a === 0) return b
         b %= a
     }
 }
+function LCM(a, b) { return (!a || !b) ? 0 : Math.abs((a * b) / GCD(a, b)) }
 
-function LCM(a, b) {
-    return (!a || !b) ? 0 : Math.abs((a * b) / GCD(a, b))
-}
-
-
-
-//println("Reading...")
-//serial.println("!!! READING")
-
-seqread.prepare(filename)
-
-
-
-
-// decode header
-if (seqread.readFourCC() != "RIFF") {
-    throw Error("File not RIFF")
-}
-
-const FILE_SIZE = seqread.readInt() // size from "WAVEfmt"
-
-if (seqread.readFourCC() != "WAVE") {
-    throw Error("File is RIFF but not WAVE")
-}
+seqread.prepare(filePath)
+if (seqread.readFourCC() !== "RIFF") throw Error("File not RIFF")
+const FILE_SIZE = seqread.readInt()
+if (seqread.readFourCC() !== "WAVE") throw Error("File is RIFF but not WAVE")
 
 let BLOCK_SIZE = 0
 let INFILE_BLOCK_SIZE = 0
-const QUEUE_MAX = 8 // according to the spec
+const QUEUE_MAX = 8
 
-let pcmType;
-let nChannels;
-let samplingRate;
-let blockSize;
-let bitsPerSample;
-let byterate;
-let comments = {};
-let adpcmSamplesPerBlock;
-let readPtr = undefined
-let decodePtr = undefined
+let pcmType, nChannels, samplingRate, blockSize, bitsPerSample, byterate
+let adpcmSamplesPerBlock
+let readPtr, decodePtr
+const comments = {}
 
 function bytesToSec(i) {
     if (adpcmSamplesPerBlock) {
-        let newByteRate = samplingRate
-        let generatedSamples = i / blockSize * adpcmSamplesPerBlock
-        return generatedSamples / newByteRate
-    }
-    else {
-        return i / byterate
+        const generatedSamples = i / blockSize * adpcmSamplesPerBlock
+        return generatedSamples / samplingRate
     }
+    return i / byterate
 }
-function secToReadable(n) {
-    let mins = ''+((n/60)|0)
-    let secs = ''+(n % 60)
-    return `${mins.padStart(2,'0')}:${secs.padStart(2,'0')}`
-}
+
 function checkIfPlayable() {
-    if (pcmType != 1 && pcmType != 2) return `PCM Type not LPCM/ADPCM (${pcmType})`
+    if (pcmType !== 1 && pcmType !== 2) return `PCM Type not LPCM/ADPCM (${pcmType})`
     if (nChannels < 1 || nChannels > 2) return `Audio not mono/stereo but instead has ${nChannels} channels`
-    if (pcmType != 1 && samplingRate != pcm.HW_SAMPLING_RATE) return `Format is ADPCM but sampling rate is not ${pcm.HW_SAMPLING_RATE}: ${samplingRate}`
+    if (pcmType !== 1 && samplingRate !== pcm.HW_SAMPLING_RATE)
+        return `Format is ADPCM but sampling rate is not ${pcm.HW_SAMPLING_RATE}: ${samplingRate}`
     return "playable!"
 }
-// @return decoded sample length (not count!)
+
 function decodeInfilePcm(inPtr, outPtr, inputLen) {
-    // LPCM
-    if (1 == pcmType)
+    if (pcmType === 1)
         return pcm.decodeLPCM(inPtr, outPtr, inputLen, { nChannels, bitsPerSample, samplingRate, blockSize })
-    else if (2 == pcmType)
+    if (pcmType === 2)
         return pcm.decodeMS_ADPCM(inPtr, outPtr, inputLen, { nChannels })
-    else
-        throw Error(`PCM Type not LPCM or ADPCM (${pcmType})`)
+    throw Error(`PCM Type not LPCM or ADPCM (${pcmType})`)
 }
+
 let stopPlay = false
-
-
-con.curs_set(0)
-let [__, CONSOLE_WIDTH] = con.getmaxyx()
-function printPlayerShell() {
-if (interactive) {
-    let [cy, cx] = con.getyx()
-    // file name
-    con.mvaddch(cy, 1)
-    con.prnch(0xC9);con.prnch(0xCD);con.prnch(0xB5)
-    print(fileeeee.name)
-    con.prnch(0xC6);con.prnch(0xCD)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 26 - fileeeee.name.length))
-    con.prnch(0xB5)
-    print("Hold Bksp to Exit")
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBB)
-
-    // L R pillar
-    con.prnch(0xBA)
-    con.mvaddch(cy+1, CONSOLE_WIDTH, 0xBA)
-
-    // media info
-    let mediaInfoStr = `WAV ${WAV_FORMATS[pcmType-1]} ${WAV_CHANNELS[nChannels-1]} ${byterate*0.008*(pcmType == 2 ? 2 : 1)}kbps`
-    con.move(cy+2,1)
-    con.prnch(0xC8)
-    print("\x84205u".repeat(CONSOLE_WIDTH - 5 - mediaInfoStr.length))
-    con.prnch(0xB5)
-    print(mediaInfoStr)
-    con.prnch(0xC6);con.prnch(0xCD);con.prnch(0xBC)
-
-    con.move(cy+1, 2)
-}
-}
-let [cy, cx] = con.getyx(); cy++
-let paintWidth = CONSOLE_WIDTH - 20
-function printPlayBar(startOffset) {
-    if (interactive) {
-        let currently = seqread.getReadCount() - startOffset
-        let total = FILE_SIZE - startOffset - 8
-
-        let currentlySec = Math.round(bytesToSec(currently))
-        let totalSec = Math.round(bytesToSec(total))
-
-        con.move(cy, 3)
-        print(' '.repeat(15))
-        con.move(cy, 3)
-
-        print(`${secToReadable(currentlySec)} / ${secToReadable(totalSec)}`)
-
-        con.move(cy, 17)
-        print(' ')
-        let progressbar = '\x84196u'.repeat(paintWidth + 1)
-        print(progressbar)
-
-        con.mvaddch(cy, 18 + Math.round(paintWidth * (currently / total)), 0xDB)
-    }
-}
 let errorlevel = 0
-// read chunks loop
-try {
-while (!stopPlay && seqread.getReadCount() < FILE_SIZE - 8) {
-    let chunkName = seqread.readFourCC()
-    let chunkSize = seqread.readInt()
-    printdbg(`Reading '${chunkName}' at ${seqread.getReadCount() - 8}`)
 
-    // here be lotsa if-else
-    if ("fmt " == chunkName) {
-        pcmType = seqread.readShort()
-        nChannels = seqread.readShort()
-        samplingRate = seqread.readInt()
-        byterate = seqread.readInt()
-        blockSize = seqread.readShort()
-        bitsPerSample = seqread.readShort()
-        if (pcmType != 2) {
-            seqread.skip(chunkSize - 16)
+try {
+    while (!stopPlay && seqread.getReadCount() < FILE_SIZE - 8) {
+        const chunkName = seqread.readFourCC()
+        const chunkSize = seqread.readInt()
+        printdbg(`Reading '${chunkName}' at ${seqread.getReadCount() - 8}`)
+
+        if (chunkName === "fmt ") {
+            pcmType       = seqread.readShort()
+            nChannels     = seqread.readShort()
+            samplingRate  = seqread.readInt()
+            byterate      = seqread.readInt()
+            blockSize     = seqread.readShort()
+            bitsPerSample = seqread.readShort()
+            if (pcmType !== 2) {
+                seqread.skip(chunkSize - 16)
+            } else {
+                seqread.skip(2)
+                adpcmSamplesPerBlock = seqread.readShort()
+                seqread.skip(chunkSize - (16 + 4))
+            }
+
+            if (pcmType === 1) {
+                const incr = LCM(blockSize, samplingRate / GCD(samplingRate, pcm.HW_SAMPLING_RATE))
+                while (BLOCK_SIZE < 4096) BLOCK_SIZE += incr
+                INFILE_BLOCK_SIZE = BLOCK_SIZE * bitsPerSample / 8
+            } else if (pcmType === 2) {
+                BLOCK_SIZE = blockSize
+                INFILE_BLOCK_SIZE = BLOCK_SIZE
+            }
+
+            if (interactive) {
+                const tag = "WAV"
+                const title = fileHandle.name +
+                    `  ${WAV_FORMATS[pcmType-1]} ${WAV_CHANNELS[nChannels-1]} ${byterate*0.008*(pcmType === 2 ? 2 : 1)}kbps`
+                gui.audioInit({ title, tag })
+            }
+        }
+        else if (chunkName === "LIST") {
+            const startOffset = seqread.getReadCount()
+            const subChunkName = seqread.readFourCC()
+            while (seqread.getReadCount() < startOffset + chunkSize) {
+                if (subChunkName === "INFO") {
+                    let key = seqread.readFourCC()
+                    let valueLen = seqread.readInt()
+                    while (key.charCodeAt(0) === 0) {
+                        const kbytes = [key.charCodeAt(1), key.charCodeAt(2), key.charCodeAt(3), valueLen & 255]
+                        const klen   = [(valueLen >>> 8) & 255, (valueLen >>> 16) & 255, (valueLen >>> 24) & 255, seqread.readOneByte()]
+                        key = String.fromCharCode.apply(null, kbytes)
+                        valueLen = klen[0] | (klen[1] << 8) | (klen[2] << 16) | (klen[3] << 24)
+                    }
+                    comments[key] = seqread.readString(valueLen)
+                } else {
+                    seqread.skip(startOffset + chunkSize - seqread.getReadCount())
+                }
+            }
+        }
+        else if (chunkName === "data") {
+            const startOffset = seqread.getReadCount()
+            const reason = checkIfPlayable()
+            if (reason !== "playable!") throw Error("WAVE not playable: " + reason)
+
+            readPtr   = sys.malloc(pcmType === 2 ? BLOCK_SIZE : BLOCK_SIZE * bitsPerSample / 8)
+            decodePtr = sys.malloc(BLOCK_SIZE * pcm.HW_SAMPLING_RATE / samplingRate)
+
+            audio.resetParams(0)
+            audio.purgeQueue(0)
+            audio.setPcmMode(0)
+            audio.setMasterVolume(0, 255)
+
+            let readLength = 1
+            while (!stopPlay && seqread.getReadCount() < startOffset + chunkSize && readLength > 0) {
+                if (interactive && gui.audioIsExitRequested()) { stopPlay = true; break }
+
+                if (audio.getPosition(0) <= 1) {
+                    for (let repeat = 0; repeat < QUEUE_MAX; repeat++) {
+                        const remainingBytes = FILE_SIZE - 8 - seqread.getReadCount()
+                        readLength = (remainingBytes < INFILE_BLOCK_SIZE) ? remainingBytes : INFILE_BLOCK_SIZE
+                        if (readLength <= 0) break
+
+                        seqread.readBytes(readLength, readPtr)
+                        const decodedSampleLength = decodeInfilePcm(readPtr, decodePtr, readLength)
+
+                        // Hand the decoded PCMu8 stereo block to the visualiser
+                        // before queueing — the buffer is reused next iteration.
+                        if (interactive) gui.audioFeedPcm(decodePtr, decodedSampleLength >> 1)
+
+                        audio.putPcmDataByPtr(0, decodePtr, decodedSampleLength, 0)
+                        audio.setSampleUploadLength(0, decodedSampleLength)
+                        audio.startSampleUpload(0)
+
+                        sys.spin()
+                    }
+                    audio.play(0)
+                }
+
+                if (interactive) {
+                    const cur = seqread.getReadCount() - startOffset
+                    const tot = FILE_SIZE - startOffset - 8
+                    gui.audioSetProgress(cur / tot, bytesToSec(cur), bytesToSec(tot))
+                    gui.audioRender()
+                }
+                sys.sleep(10)
+            }
         }
         else {
-            seqread.skip(2)
-            adpcmSamplesPerBlock = seqread.readShort()
-            seqread.skip(chunkSize - (16 + 4))
+            seqread.skip(chunkSize)
         }
 
-        // define BLOCK_SIZE as integer multiple of blockSize, for LPCM
-        // ADPCM will be decoded per-block basis
-        if (1 == pcmType) {
-            // get GCD of given values; this wll make resampling headache-free
-            let blockSizeIncrement = LCM(blockSize, samplingRate / GCD(samplingRate, pcm.HW_SAMPLING_RATE))
-
-            while (BLOCK_SIZE < 4096) {
-                BLOCK_SIZE += blockSizeIncrement // for rate 44100, BLOCK_SIZE will be 4116
-            }
-            INFILE_BLOCK_SIZE = BLOCK_SIZE * bitsPerSample / 8 // for rate 44100, INFILE_BLOCK_SIZE will be 8232
-        }
-        else if (2 == pcmType) {
-            BLOCK_SIZE = blockSize
-            INFILE_BLOCK_SIZE = BLOCK_SIZE
-        }
-
-        printdbg(`Format: ${pcmType}, Channels: ${nChannels}, Rate: ${samplingRate}, BitDepth: ${bitsPerSample}`)
-        printdbg(`BLOCK_SIZE=${BLOCK_SIZE}, INFILE_BLOCK_SIZE=${INFILE_BLOCK_SIZE}`)
-        printPlayerShell()
+        sys.spin()
     }
-    else if ("LIST" == chunkName) {
-        let startOffset = seqread.getReadCount()
-        let subChunkName = seqread.readFourCC()
-        while (seqread.getReadCount() < startOffset + chunkSize) {
-            if ("INFO" == subChunkName) {
-                let key = seqread.readFourCC()
-                let valueLen = seqread.readInt()
-
-                // f-you WAVE encoders with nonstandard behaviours
-                // related: https://stackoverflow.com/questions/49537639/riff-icmt-tag-size-doesnt-seem-to-match-data
-                while (0 == key.charCodeAt(0)) {
-                    printdbg(`Previous key had more zero bytes padded than its marked length, skipping one byte...`)
-
-                    let kbytes = [key.charCodeAt(1), key.charCodeAt(2), key.charCodeAt(3), valueLen & 255]
-                    let klen = [(valueLen >>> 8) & 255, (valueLen >>> 16) & 255, (valueLen >>> 24) & 255, seqread.readOneByte()]
-
-                    key = String.fromCharCode.apply(null, kbytes)
-                    valueLen = klen[0] | (klen[1] << 8) | (klen[2] << 16) | (klen[3] << 24)
-                }
-
-                printdbg(`Reading LIST INFO ${key}[${[0,1,2,3].map((i)=>"0x"+key.charCodeAt(i).toString(16).padStart(2,'0'))}] (${valueLen} bytes): `)
-
-
-                let value = seqread.readString(valueLen)
-                printdbg("   |"+value)
-                comments[key] = value
-            }
-            else {
-                printdbg(`LIST skip subchunk ${subChunkName} (${startOffset + chunkSize - seqread.getReadCount()} bytes)`)
-                seqread.skip(startOffset + chunkSize - seqread.getReadCount())
-            }
-        }
-        printComments()
-    }
-    else if ("data" == chunkName) {
-        let startOffset = seqread.getReadCount()
-
-        printdbg(`WAVE size: ${chunkSize}, startOffset=${startOffset}`)
-        // check if the format is actually playable
-        let unplayableReason  = checkIfPlayable()
-        if (unplayableReason != "playable!") throw Error("WAVE not playable: "+unplayableReason)
-
-        if (pcmType == 2)
-            readPtr = sys.malloc(BLOCK_SIZE)
-        else
-            readPtr = sys.malloc(BLOCK_SIZE * bitsPerSample / 8)
-
-        decodePtr = sys.malloc(BLOCK_SIZE * pcm.HW_SAMPLING_RATE / samplingRate)
-
-        audio.resetParams(0)
-        audio.purgeQueue(0)
-        audio.setPcmMode(0)
-        audio.setMasterVolume(0, 255)
-
-        let readLength = 1
-        while (!stopPlay && seqread.getReadCount() < startOffset + chunkSize && readLength > 0) {
-            if (interactive) {
-                sys.poke(-40, 1)
-                if (sys.peek(-41) == 67) {
-                    stopPlay = true
-                }
-            }
-
-            printPlayBar(startOffset)
-
-            let queueSize = audio.getPosition(0)
-            if (queueSize <= 1) {
-
-
-                // upload four samples for lag-safely
-                for (let repeat = 0; repeat < QUEUE_MAX; repeat++) {
-                    let remainingBytes = FILE_SIZE - 8 - seqread.getReadCount()
-
-                    readLength = (remainingBytes < INFILE_BLOCK_SIZE) ? remainingBytes : INFILE_BLOCK_SIZE
-                    if (readLength <= 0) {
-                        printdbg(`readLength = ${readLength}`)
-                        break
-                    }
-
-                    printdbg(`offset: ${seqread.getReadCount()}/${FILE_SIZE + 8}; readLength: ${readLength}`)
-
-                    seqread.readBytes(readLength, readPtr)
-
-                    let decodedSampleLength = decodeInfilePcm(readPtr, decodePtr, readLength)
-                    printdbg(`        decodedSampleLength: ${decodedSampleLength}`)
-
-                    audio.putPcmDataByPtr(0, decodePtr, decodedSampleLength, 0)
-                    audio.setSampleUploadLength(0, decodedSampleLength)
-                    audio.startSampleUpload(0)
-
-                    sys.spin()
-                }
-
-                audio.play(0)
-            }
-
-            let remainingBytes = FILE_SIZE - 8 - seqread.getReadCount()
-            printdbg(`readLength = ${readLength}; remainingBytes2 = ${remainingBytes}; seqread.getReadCount() = ${seqread.getReadCount()}; startOffset + chunkSize = ${startOffset + chunkSize}`)
-
-
-            sys.sleep(10)
-        }
-    }
-    else {
-        seqread.skip(chunkSize)
-    }
-
-
-    let remainingBytes = FILE_SIZE - 8 - seqread.getReadCount()
-    printdbg(`remainingBytes2 = ${remainingBytes}`)
-    sys.spin()
-}
-}
-catch (e) {
+} catch (e) {
     printerrln(e)
     errorlevel = 1
-}
-finally {
-    //audio.stop(0)
-    if (readPtr !== undefined) sys.free(readPtr)
+} finally {
+    if (readPtr   !== undefined) sys.free(readPtr)
     if (decodePtr !== undefined) sys.free(decodePtr)
+    if (interactive) gui.audioClose()
 }
 
 return errorlevel

assets/disk0/tvdos/bin/taut_helpmsg.js

@@ -1,6 +1,8 @@
 if (!_G.TAUT) _G.TAUT = {};
 let help = {}
 
+let ts = require("typesetter")
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 /*
@@ -18,7 +20,7 @@ Tags:
 &updn; - up-down arrow (\u008418u)
 &udlr; - four direction arrow (\u008428u\u008429u)
 
-&keyoffsym; - pattern view key-off symbol (\u00A0\u00CD\u00CD\u00A1)
+&keyoffsym; - pattern view key-off symbol (\u00A0\u00B1\u00B1\u00A1)
 &notecutsym; - pattern view note-cut symbol (\u00A4\u00A4\u00A4\u00A4)
 
 &demisharp;
@@ -44,8 +46,8 @@ Tags:
 default alignment: fully justified
  */
 
-let helpNotation = `<c>CONTROL NOTATON</c>
-
+let helpNotation = `<c>CONTROL NOTATION</c>
+<c>\u00B7${'\u00B8'.repeat(16)}\u00B9</c>
 &microtone; <O>shortcuts differentiate normal and shifted shortcuts.</O>
 &bul;<b>a</b>&ddot;<b>z</b> : <O>alphabet without shift-in</O>
 &bul;<b>A</b>&ddot;<b>Z</b> : <O>alphabet with shift-in</O>
@@ -56,7 +58,7 @@ let helpNotation = `<c>CONTROL NOTATON</c>
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 let helpJam = `<c>NOTE JAMMING</c>
-
+<c>\u00B7${'\u00B8'.repeat(12)}\u00B9</c>
 Push keys to play or insert notes.
 &nbsp;w&nbsp;e&nbsp;&nbsp;&nbsp;t&nbsp;y&nbsp;u
 a&nbsp;s&nbsp;d&nbsp;f&nbsp;g&nbsp;h&nbsp;j&nbsp;k
@@ -65,322 +67,105 @@ a&nbsp;s&nbsp;d&nbsp;f&nbsp;g&nbsp;h&nbsp;j&nbsp;k
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 let helpCommon = `<c>COMMON CONTROLS</c>
-
+<c>\u00B7${'\u00B8'.repeat(15)}\u00B9</c>
 &bul;<b>!</b> : <O>show this help message</O>
-&bul;<b>Y</b> : <O>play the entire song from the current cue</O>
-&bul;<b>U</b> : <O>play the current cue then stop</O>
-&bul;<b>I</b> : <O>play the current row</O>
-&bul;<b>O</b> : <O>stop the playback</O>
-&bul;<b>tab</b> : <O>switch forward a tab</O>
-&bul;<b>TAB</b> : <O>switch backward a tab</O>
-&bul;<b>q</b> : <O>close &microtone;</O>
+&bul;<b>Y</b> : <O>plays the entire song from the current cue</O>
+&bul;<b>U</b> : <O>plays the current cue then stop</O>
+&bul;<b>I</b> : <O>plays the current row</O>
+&bul;<b>O</b> : <O>stops the playback</O>
+&bul;<b>tab</b> : <O>switchs forward a tab</O>
+&bul;<b>TAB</b> : <O>switchs backward a tab</O>
+&bul;<b>q</b> : <O>closes &microtone;</O>
 `
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 let helpTimeline = `<c>TIMELINE VIEW</c>
-
+<c>\u00B7${'\u00B8'.repeat(13)}\u00B9</c>
 Timeline has two distinct modes: view and edit mode. Two modes are toggled using the space bar.
 
-<b>VIEW MODE</b>
+<b>&nbsp;VIEW MODE</b>
+<b>\u00B7${'\u00B8'.repeat(9)}\u00B9</b>
 &bul;Note jamming : <O>plays the note</O>
-&bul;<b>&udlr;</b> : <O>move the viewing cursor by voices and rows</O>
-&bul;<b>pg&updn;</b> : <O>go to previous/next cue</O>
-&bul;<b>W</b>&mdot;<b>E</b>&mdot;<b>R</b> : <O>toggle timeline view mode. W-most detailed, R-most abridged</O>
-&bul;<b>n</b> : <O>toggle soloing of the selected voice</O>
-&bul;<b>m</b> : <O>toggle muting of the selected voice</O>
+&bul;<b>&udlr;</b> : <O>moves the viewing cursor by voices and rows</O>
+&bul;<b>pg&updn;</b> : <O>goes to previous/next cue</O>
+&bul;<b>W</b>&mdot;<b>E</b>&mdot;<b>R</b> : <O>toggles timeline view mode. W-most detailed, R-most abridged</O>
+&bul;<b>n</b> : <O>toggles soloing of the selected voice</O>
+&bul;<b>m</b> : <O>toggles muting of the selected voice</O>
+&bul;<b>[</b>&mdot;<b>]</b> : <O>changes tick rate of playhead</O>
 
-<b>EDIT MODE</b>
+<b>&nbsp;EDIT MODE</b>
+<b>\u00B7${'\u00B8'.repeat(9)}\u00B9</b>
 &bul;Note jamming : <O>(note column) inserts the note</O>
-&bul;<b>{</b>&mdot;<b>}</b> : <O>(note column) lower/raise a note by one octave (or period)</O>
-&bul;<b>[</b>&mdot;<b>]</b> : <O>(note column) lower/raise a note by one unit</O>
-&bul;<b>=</b> : <O>(note column) insert a key-off &keyoffsym;</O>
-&bul;<b>^</b> : <O>(note column) insert a note-cut &notecutsym;</O>
-&bul;<b>.</b> : <O>remove a symbol on the selected column</O>
-&bul;<b>bksp</b> : <O>delete one character on the selected column</O>
+&bul;<b>{</b>&mdot;<b>}</b> : <O>(note column) lowers/raises a note by one octave (or period)</O>
+&bul;<b>[</b>&mdot;<b>]</b> : <O>(note column) lowers/raises a note by one unit</O>
+&bul;<b>z</b> : <O>(note column) inserts a key-off &keyoffsym;</O>
+&bul;<b>x</b> : <O>(note column) inserts a note-cut &notecutsym;</O>
+&bul;<b>.</b> : <O>clears fields</O>
+&bul;<b>bksp</b> : <O>deletes one character on the selected column</O>
 &bul;<b>0</b>&ddot;<b>9</b> <b>a</b>&ddot;<b>f</b> : <O>inserts a (hexa)decimal number</O>
+&bul;<b>0</b>&ddot;<b>9</b> <b>a</b>&ddot;<b>z</b> : <O>(fx column) inserts an effect</O>
 &bul;<b>^</b>&mdot;<b>v</b> : <O>(volume column) slide up/down</O>
 &bul;<b>&lt;</b>&mdot;<b>&gt;</b>: <O>(panning column) slide left/right</O>
 &bul;<b>-</b>&mdot;<b>=</b> : <O>(vol/pan col) fine slide down/up</O>
-&bul;<b>&udlr;</b> : <O>move the viewing cursor by columns and rows</O>
-&bul;<b>pg&updn;</b> : <O>go to previous/next cue</O>
+&bul;<b>&udlr;</b> : <O>moves the viewing cursor by columns and rows</O>
+&bul;<b>pg&updn;</b> : <O>goes to previous/next cue</O>
 
-<b>ACCIDENTALS</b>
+<b>&nbsp;ACCIDENTALS</b>
+<b>\u00B7${'\u00B8'.repeat(11)}\u00B9</b>
 &demisharp;&nbsp;&sharp;&nbsp;&doublesharp;&nbsp;&triplesharp;&nbsp;&quadsharp;&nbsp;&demiflat;&nbsp;&flat;&nbsp;&doubleflat;&nbsp;&tripleflat;&nbsp;&nbsp;&accuptick;&nbsp;&nbsp;&accupup;&nbsp;&nbsp;&accdntick;&nbsp;&nbsp;&accdndn;
 <b>C&nbsp;&nbsp;c&nbsp;&nbsp;cx&nbsp;x&nbsp;&nbsp;xx&nbsp;B&nbsp;&nbsp;b&nbsp;&nbsp;bb&nbsp;bbb&nbsp;^&nbsp;&nbsp;^^&nbsp;v&nbsp;&nbsp;vv</b>
+
+<b>&nbsp;GLOBAL EDIT</b>
+<b>\u00B7${'\u00B8'.repeat(11)}\u00B9</b>
+&bul;<b>Q</b> : <O>retunes current song into different tuning and strategy. In general, nearest-note works best for macrotonals, nearest-harmonic and nearest-delta works best for highly microtonals (31+); 17- and 19-TET takes nearest-harmonic pretty well, while 22-TET seem to only benefit from the nearest-note</O>
+`
+
+let helpProjectFlags = `<c>MIXER FLAGS</c>
+<c>\u00B7${'\u00B8'.repeat(11)}\u00B9</c>
+Mixer flags define how should the mixer behave.
+
+<b>&nbsp;TONE MODE</b>
+<b>\u00B7${'\u00B8'.repeat(9)}\u00B9</b>
+&bul;Linear pitch : <O>pitch shift effects operate on linear pitch scale. The default and recommended setting for a new project</O>
+&bul;Amiga pitch : <O>pitch shift effects operate on Amiga period scale. Backwards compatible setting for MOD/S3M/XM/IT formats</O>
+&bul;Linear freq : <O>pitch shift effects operate on linear frequency scale. Backwards compatible setting for MONOTONE format</O>
+
+<b>&nbsp;INTERPOLATION</b>
+<b>\u00B7${'\u00B8'.repeat(13)}\u00B9</b>
+&bul;Default : <O>three-tap fast sinc interpolation. The default and recommended setting for a new project</O>
+&bul;None : <O>zeroth-order hold</O>
+&bul;A500 : <O>emulates what Paula chip of Amiga 500 does. <b>S 0x00</b> effects only work with this and Amiga 1200 mode</O>
+&bul;A1200 : <O>emulates what Paula chip of Amiga 1200 does</O>
+&bul;SNES : <O>four-tap gaussian interpolation used by SNES</O>
+&bul;DPCM : <O>simulates Differential Pulse Code Modulation used by NES</O>
 `
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 // assemble help text pieces to complete help message
 
-const SCRW = con.getmaxyx()[1]
+const HRULE = '\u00B4\u00B5'.repeat((_G.TAUT.HELPMSG_WIDTH) >>> 1) + '\n'
 
-// Display-command palette. taut.js's popup uses (HELP_COL_TEXT on background) as the
-// default colour pair, so embedded `\x1B[38;5;Nm` codes switch foreground only.
-const HELP_COL_TEXT      = 239 // popup body default (== colWHITE)
-const HELP_COL_EMPH      = 230 // <b>...</b> highlight (== colVoiceHdr)
-const HELP_COL_BRAND     = 211 // first half of "Microtone"
-const HELP_COL_BRAND_DIM = 239 // second half of "Microtone"
-
-const fgEsc = (n) => `\x1B[38;5;${n}m`
-const ESC_DEFAULT = fgEsc(HELP_COL_TEXT)
-const ESC_EMPH    = fgEsc(HELP_COL_EMPH)
-const MICROTONE   = `${fgEsc(HELP_COL_BRAND)}Micro${fgEsc(HELP_COL_BRAND_DIM)}tone${ESC_DEFAULT}`
-
-// Replace &xxx; entities with their final printable representations.
-function expandEntities(s) {
-    return s
-        .replaceAll('&microtone;',  MICROTONE)
-        .replaceAll('&bul;',        '\u00F9')
-        .replaceAll('&ddot;',       '\u008419u')
-        .replaceAll('&mdot;',       '\u00FA')
-        .replaceAll('&updn;',       '\u008418u')
-        .replaceAll('&udlr;',       '\u008428u\u008429u')
-        .replaceAll('&keyoffsym;',  '\u00A0\u00CD\u00CD\u00A1')
-        .replaceAll('&notecutsym;', '\u00A4\u00A4\u00A4\u00A4')
-        .replaceAll('&nbsp;',       '\u007F')
-        .replaceAll('&shy;',        '')
-        .replaceAll('&lt;',        '<')
-        .replaceAll('&gt;',        '>')
-        .replaceAll('&demisharp;',   '\u0080\u0081')
-        .replaceAll('&sharp;',       '\u0082\u0083')
-        .replaceAll('&sesquisharp;', '\u0084132u\u0085')
-        .replaceAll('&doublesharp;', '\u0086\u0087')
-        .replaceAll('&triplesharp;', '\u0088\u0089')
-        .replaceAll('&quadsharp;',   '\u008A\u008B')
-        .replaceAll('&demiflat;',    '\u008C\u008D')
-        .replaceAll('&flat;',        '\u008E\u008F')
-        .replaceAll('&sesquiflat;',  '\u0090\u0091')
-        .replaceAll('&doubleflat;',  '\u0092\u0093')
-        .replaceAll('&tripleflat;',  '\u0094\u0095')
-        .replaceAll('&quadflat;',    '\u0096\u0097')
-        .replaceAll('&accuptick;',    '\u009A')
-        .replaceAll('&accdntick;',    '\u009B')
-        .replaceAll('&accupup;',    '\u009C')
-        .replaceAll('&accdndn;',    '\u009D')
-}
-
-// Tokenise a (post-entity-expansion) line. Returns an array of:
-//   {type:'word',   text:String, w:int}  - non-breakable run of visible chars (may carry ANSI escapes)
-//   {type:'sp'}                          - a single soft space (eligible for break/expansion)
-//   {type:'anchor', open:Boolean}        - <o>/</o> markers (zero width)
-//
-// Width accounting:
-//   - ANSI escapes (`\x1B[...m`)         : 0 visible chars
-//   - TSVM unicode escapes (`„..u`) : 1 visible char
-//   - non-breaking space ( )        : 1 visible char (consumed as part of a word)
-//   - soft hyphen (­)               : dropped (not implemented as a break point)
-//   - everything else                    : 1 visible char
-function tokenise(line) {
-    const tokens = []
-    let buf = ''
-    let bufW = 0
-    let i = 0
-
-    const flushWord = () => {
-        if (buf.length > 0) {
-            tokens.push({type: 'word', text: buf, w: bufW})
-            buf = ''
-            bufW = 0
-        }
-    }
-
-    while (i < line.length) {
-        // inline tags (case-sensitive for <b>, case-insensitive for <o>)
-        if (line.slice(i, i + 3) === '<b>')  { buf += ESC_EMPH;    i += 3; continue }
-        if (line.slice(i, i + 4) === '</b>') { buf += ESC_DEFAULT; i += 4; continue }
-        const head3 = line.slice(i, i + 3).toLowerCase()
-        const head4 = line.slice(i, i + 4).toLowerCase()
-        if (head3 === '<o>')  { flushWord(); tokens.push({type: 'anchor', open: true});  i += 3; continue }
-        if (head4 === '</o>') { flushWord(); tokens.push({type: 'anchor', open: false}); i += 4; continue }
-
-        const c  = line[i]
-        const cc = line.charCodeAt(i)
-
-        if (cc === 0x1B) {
-            // pre-existing ANSI escape - copy verbatim, zero visible width
-            const m = line.indexOf('m', i)
-            const end = (m < 0) ? line.length : m + 1
-            buf += line.slice(i, end)
-            i = end
-        }
-        else if (cc === 0x84) {
-            // TSVM „<digits>u escape - copy verbatim, one visible char
-            const u = line.indexOf('u', i)
-            const end = (u < 0) ? line.length : u + 1
-            buf += line.slice(i, end)
-            bufW += 1
-            i = end
-        }
-        else if (c === ' ') {
-            flushWord()
-            tokens.push({type: 'sp'})
-            i += 1
-        }
-        else if (cc === 0x00AD) {
-            // soft hyphen: drop (no break-point handling for now)
-            i += 1
-        }
-        else {
-            buf += c
-            bufW += 1
-            i += 1
-        }
-    }
-    flushWord()
-    return tokens
-}
-
-// Build wrapped lines from a token stream then format each one according to alignment.
-// Returns an array of strings, each exactly `width` visible chars wide (padded with
-// trailing spaces) so the caller can blit them without further math.
-function wrapAndAlign(tokens, width, alignment) {
-    const lines = [] // each: {tokens, indent, contentW}
-    let curTokens = []
-    let curW = 0
-    let curIndent = 0
-    let nextIndent = 0 // indent the *next* flushed line should use
-
-    const flushLine = () => {
-        // strip trailing soft spaces
-        while (curTokens.length > 0 && curTokens[curTokens.length - 1].type === 'sp') {
-            curTokens.pop()
-            curW -= 1
-        }
-        lines.push({tokens: curTokens, indent: curIndent, contentW: curW})
-        curTokens = []
-        curW = 0
-        curIndent = nextIndent
-    }
-
-    for (const tok of tokens) {
-        if (tok.type === 'anchor') {
-            // anchor opens at the current visible column (accounting for indent)
-            if (tok.open) nextIndent = curIndent + curW
-            else          nextIndent = 0
-            continue
-        }
-
-        if (tok.type === 'sp') {
-            // ignore leading soft spaces on a fresh line
-            if (curW === 0) continue
-            // hard wrap if the line is already at the right edge
-            if (curIndent + curW + 1 > width) { flushLine(); continue }
-            curTokens.push(tok)
-            curW += 1
-            continue
-        }
-
-        // word
-        const tw = tok.w
-        if (curIndent + curW + tw > width) {
-            flushLine()
-            // word too wide for the wrapped line: emit it on its own row (possibly clipped by terminal)
-            if (curIndent + tw > width) {
-                curTokens.push(tok)
-                curW += tw
-                flushLine()
-                continue
-            }
-        }
-        curTokens.push(tok)
-        curW += tw
-    }
-
-    if (curTokens.length > 0 || lines.length === 0) flushLine()
-
-    return lines.map((line, i) => formatLine(line, width, alignment, i === lines.length - 1))
-}
-
-function formatLine(line, totalWidth, alignment, isLast) {
-    if (line.tokens.length === 0) return ' '.repeat(totalWidth)
-
-    const indent    = ' '.repeat(line.indent)
-    const remaining = totalWidth - line.indent - line.contentW
-    const pad       = (n) => (n > 0) ? ' '.repeat(n) : ''
-    const flatText  = () => line.tokens.map(t => (t.type === 'sp') ? ' ' : t.text).join('')
-
-    if (alignment === 'c') {
-        const left = remaining >> 1
-        return indent + pad(left) + flatText() + pad(remaining - left)
-    }
-    if (alignment === 'r') return indent + pad(remaining) + flatText()
-    if (alignment === 'l') return indent + flatText() + pad(remaining)
-
-    // justified: only expand spaces when there's slack and we're not on the
-    // last (or single) wrapped line
-    if (isLast || remaining <= 0) return indent + flatText() + pad(remaining)
-
-    const spaceCount = line.tokens.reduce((n, t) => n + (t.type === 'sp' ? 1 : 0), 0)
-    if (spaceCount === 0) return indent + flatText() + pad(remaining)
-
-    const baseExtra = (remaining / spaceCount) | 0
-    let leftover    = remaining - baseExtra * spaceCount
-
-    let out = indent
-    for (const tok of line.tokens) {
-        if (tok.type === 'sp') {
-            const extra = baseExtra + (leftover > 0 ? 1 : 0)
-            if (leftover > 0) leftover -= 1
-            out += ' '.repeat(1 + extra)
-        } else {
-            out += tok.text
-        }
-    }
-    return out
-}
-
-// Process a single source line: peel a leading <c>/<r>/<l> alignment tag (if present),
-// strip its matching close tag, then tokenise + wrap.
-function typesetSourceLine(line, width) {
-    if (line.length === 0) return [' '.repeat(width)]
-
-    let alignment = 'j' // justified default
-    const startMatch = line.match(/^<([crl])>/i)
-    if (startMatch) {
-        alignment = startMatch[1].toLowerCase()
-        line = line.slice(startMatch[0].length)
-        const closeRe = new RegExp(`</${alignment}>$`, 'i')
-        line = line.replace(closeRe, '')
-    }
-
-    const tokens = tokenise(line)
-    return wrapAndAlign(tokens, width, alignment)
-}
-
-function typesetText(text, width) {
-    text = expandEntities(text)
-    const out = []
-    for (const srcLine of text.split('\n')) {
-        for (const outLine of typesetSourceLine(srcLine, width)) out.push(outLine)
-    }
-    return out
-}
-
-function typeset(text, customWidth) {
-    let typesetWidth = customWidth
-    if (typesetWidth === undefined) typesetWidth = _G.TAUT.HELPMSG_WIDTH
-    if (typesetWidth === undefined) {
-        const currentPosX = con.getyx()[1] // 1-indexed
-        typesetWidth = SCRW - currentPosX + 1
-    }
-    return typesetText(text, typesetWidth)
+// taut.js's popup uses (HELP_COL_TEXT on background) as the default colour pair.
+// The shared typesetter module owns the palette and the markup expander.
+function typeset(text) {
+    return ts.typeset(text, _G.TAUT.HELPMSG_WIDTH)
 }
 
 let helpMessages = [ // index: taut.js PANEL_NAMES
-    [helpJam, helpTimeline, helpCommon, helpNotation].join('\n'),
-    [helpCommon, helpNotation].join('\n'), // placeholder
-    [helpCommon, helpNotation].join('\n'), // placeholder
-    [helpCommon, helpNotation].join('\n'), // placeholder
-    [helpCommon, helpNotation].join('\n'), // placeholder
-    [helpCommon, helpNotation].join('\n'), // placeholder
-    [helpCommon, helpNotation].join('\n'), // placeholder
+    /* Timeline */[helpJam, helpTimeline, helpCommon, helpNotation].join(HRULE),
+    /* Cues */[helpCommon, helpNotation].join(HRULE), // placeholder
+    /* Patterns */[helpCommon, helpNotation].join(HRULE), // placeholder
+    /* Samples */[helpCommon, helpNotation].join(HRULE), // placeholder
+    /* Instruments */[helpCommon, helpNotation].join(HRULE), // placeholder
+    /* Project */[helpProjectFlags, helpCommon, helpNotation].join(HRULE), // placeholder
+    /* File */[helpCommon, helpNotation].join(HRULE), // placeholder
 ]
 
 help.MSG_BY_TABS = helpMessages.map(it => typeset(it))
 help.typeset     = typeset
-help.COL_TEXT    = HELP_COL_TEXT
-help.COL_EMPH    = HELP_COL_EMPH
+help.COL_TEXT    = ts.COL_TEXT
+help.COL_EMPH    = ts.COL_EMPH
 
 if (!_G.TAUT.HELPMSG) _G.TAUT.HELPMSG=help;

assets/disk0/tvdos/bin/taut_sampleedit.js

@@ -1,18 +1,23 @@
 /**
- * TAUT Sample Editor
- * Sub-program launched by taut.js when the Samples tab is active.
- * Rows 1-3 are owned by the parent; this program draws rows 4+.
+ * TAUT Sample Editor (stub)
+ * Sub-program launched from taut.js's Samples viewer. Rows 1-3 are owned by
+ * the parent; this program draws rows 4+.
  *
- * exec_args[1] = path to .taud file
- * Sets _G.TAUT.UI.NEXTPANEL before returning to request a panel switch.
+ * exec_args:
+ *   [1] = path to .taud file
+ *   [2] = parent panel index (where to return)
+ *   [3] = sample index to preload (-1 if none)
+ *
+ * Sets _G.TAUT.UI.NEXTPANEL on return to request a panel switch back.
  *
  * Created by minjaesong on 2026-04-27
+ * Stub editing UI added on 2026-05-26
  */
 
 const win = require("wintex")
 
-const PANEL_COUNT = 7
-const MY_PANEL   = 3 // VIEW_SAMPLES
+const PARENT_PANEL = (exec_args[2] !== undefined) ? (exec_args[2] | 0) : 3 // VIEW_SAMPLES
+const SAMPLE_IDX   = (exec_args[3] !== undefined) ? (exec_args[3] | 0) : -1
 
 const [SCRH, SCRW] = con.getmaxyx()
 const PANEL_Y = 4
@@ -21,38 +26,122 @@ const PANEL_H = SCRH - PANEL_Y
 const colStatus  = 253
 const colContent = 240
 const colHdr     = 230
+const colEmph    = 211
+const colDim     = 246
+const colBack    = 255
+const colSel     = 41
 
-function drawSampleEditContents(wo) {
+// Stub editor "fields": pretend toolbar. None of these write anything yet.
+const TOOLS = [
+    { key: 'L', label: 'Load .raw / .wav from disk' },
+    { key: 'S', label: 'Save current sample to disk' },
+    { key: 'D', label: 'Draw waveform freehand' },
+    { key: 'X', label: 'Crop / trim selection' },
+    { key: 'R', label: 'Resample' },
+    { key: 'V', label: 'Reverse' },
+    { key: 'N', label: 'Normalise to peak' },
+    { key: 'F', label: 'Fade in / out' },
+]
+
+let toolCursor = 0
+
+function drawSampleEditFrame() {
     for (let y = PANEL_Y; y < SCRH; y++) {
         con.move(y, 1)
-        con.color_pair(colContent, 255)
+        con.color_pair(colContent, colBack)
         print(' '.repeat(SCRW))
     }
+    // Title
     con.move(PANEL_Y + 1, 3)
-    con.color_pair(colHdr, 255)
-    print('[ Sample Editor ]')
-    con.move(PANEL_Y + 3, 3)
-    con.color_pair(colStatus, 255)
-    print('placeholder — not yet implemented')
+    con.color_pair(colHdr, colBack); print('[ Sample Editor ]  ')
+    con.color_pair(colEmph, colBack); print('Sample ')
+    con.color_pair(colStatus, colBack)
+    if (SAMPLE_IDX >= 0) print('#' + (SAMPLE_IDX + 1).toString(16).toUpperCase().padStart(2, '0'))
+    else                 print('(none)')
+
+    con.move(PANEL_Y + 2, 3)
+    con.color_pair(colDim, colBack)
+    print('stub editor — actions below are placeholders only.')
+}
+
+function drawToolList() {
+    const x = 5
+    const y0 = PANEL_Y + 4
+    con.move(y0, x)
+    con.color_pair(colHdr, colBack); print('Editing actions')
+    con.move(y0 + 1, x)
+    con.color_pair(colDim, colBack); print('-'.repeat(16))
+
+    for (let i = 0; i < TOOLS.length; i++) {
+        const y = y0 + 3 + i
+        const t = TOOLS[i]
+        const sel = (i === toolCursor)
+        const back = sel ? colSel : colBack
+        con.move(y, x)
+        con.color_pair(colHdr, back); print(' ' + t.key + ' ')
+        con.color_pair(colStatus, back); print('  ')
+        con.color_pair(sel ? colEmph : colStatus, back)
+        const w = SCRW - x - 6
+        const lbl = t.label.length > w ? t.label.substring(0, w) : t.label.padEnd(w)
+        print(lbl)
+    }
+
+    // Drawing-area placeholder on the right
+    const dx = 38
+    const dy0 = PANEL_Y + 4
+    const dw  = SCRW - dx - 2
+    const dh  = SCRH - dy0 - 2
+    con.move(dy0, dx)
+    con.color_pair(colHdr, colBack); print('Waveform editor')
+    con.move(dy0 + 1, dx)
+    con.color_pair(colDim, colBack); print('-'.repeat(16))
+
+    // Empty drawing rectangle made of dots
+    for (let r = 0; r < dh; r++) {
+        con.move(dy0 + 3 + r, dx)
+        con.color_pair(colDim, colBack)
+        if (r === (dh >>> 1)) print('-'.repeat(dw)) // zero line
+        else print(' '.repeat(dw))
+    }
+    con.move(dy0 + 3 + (dh >>> 1) + 1, dx)
+    con.color_pair(colDim, colBack)
+    print('(drawing surface — not yet implemented)')
 }
 
 function drawHints() {
     con.move(SCRH, 1)
-    con.color_pair(colStatus, 255)
+    con.color_pair(colStatus, colBack)
     print(' '.repeat(SCRW - 1))
     con.move(SCRH, 1)
-    con.color_pair(colHdr, 255); print('Tab ')
-    con.color_pair(colStatus, 255); print('Panel')
+    con.color_pair(colHdr, colBack); print('„28u„29u ')
+    con.color_pair(colStatus, colBack); print('Tool ')
+    con.color_pair(colHdr, colBack); print('Enter ')
+    con.color_pair(colStatus, colBack); print('Apply ')
+    con.color_pair(colHdr, colBack); print('Esc/Tab ')
+    con.color_pair(colStatus, colBack); print('Back to viewer')
+}
+
+function flashAction(idx) {
+    const t = TOOLS[idx]
+    if (!t) return
+    con.move(SCRH - 2, 5)
+    con.color_pair(colEmph, colBack)
+    print(('Action: ' + t.label + ' (stub, no-op)').padEnd(SCRW - 8))
 }
 
 function sampleEditInput(wo, event) {
-    // placeholder — no interaction yet
+    // wintex panel input — wired up but the loop below handles keys directly.
 }
 
-const panel = new win.WindowObject(1, PANEL_Y, SCRW, PANEL_H, sampleEditInput, drawSampleEditContents, undefined, ()=>{})
+function drawAll() {
+    drawSampleEditFrame()
+    drawToolList()
+    drawHints()
+}
+
+const panel = new win.WindowObject(1, PANEL_Y, SCRW, PANEL_H, sampleEditInput, drawAll, undefined, ()=>{})
 
 panel.drawContents()
-drawHints()
 
 let done = false
 while (!done) {
@@ -60,17 +149,32 @@ while (!done) {
         if (event[0] !== 'key_down') return
         const keysym     = event[1]
         const keyJustHit = (1 == event[2])
-        const shiftDown  = (event.includes(59) || event.includes(60))
 
         if (!keyJustHit) return
 
-        if (keysym === '<TAB>') {
-            _G.TAUT.UI.NEXTPANEL = (MY_PANEL + (shiftDown ? -1 : 1) + PANEL_COUNT) % PANEL_COUNT
+        if (keysym === '<ESCAPE>' || keysym === '<TAB>') {
+            _G.TAUT.UI.NEXTPANEL = PARENT_PANEL
             done = true
             return
         }
 
-        panel.processInput(event)
+        if (keysym === '<UP>')   { if (toolCursor > 0)              toolCursor--; drawToolList(); return }
+        if (keysym === '<DOWN>') { if (toolCursor < TOOLS.length-1) toolCursor++; drawToolList(); return }
+
+        if (keysym === '\n') {
+            flashAction(toolCursor)
+            return
+        }
+
+        // Direct key shortcuts
+        for (let i = 0; i < TOOLS.length; i++) {
+            if (keysym === TOOLS[i].key.toLowerCase() || keysym === TOOLS[i].key) {
+                toolCursor = i
+                drawToolList()
+                flashAction(i)
+                return
+            }
+        }
     })
 }
 

assets/disk0/tvdos/hopper/getopt.hop.per

@@ -0,0 +1,11 @@
+HopperManifestVersion:1
+HopperPackageName:getopt
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:getopt;
+HopperRequires:
+ProperName:getopt.js
+ProperAuthor:David Pacheco
+ProperDescription:node.js implementation of POSIX getopt() (and then some)
+Licence:MIT
+SystemPackagePath:/tvdos/include/getopt.mjs

assets/disk0/tvdos/hopper/libfs.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:libfs
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:libfs;
+HopperRequires:tvdos 1.*;
+ProperName:LibFS
+ProperAuthor:CuriousTorvald
+ProperDescription:NodeJS-compatible Filesystem module for TVDOS
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/fs.mjs

assets/disk0/tvdos/hopper/libgl.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:libgl
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:libgl;
+HopperRequires:
+ProperName:LibGL
+ProperAuthor:CuriousTorvald
+ProperDescription:TVDOS Graphics Library
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/gl.mjs

assets/disk0/tvdos/hopper/libpcm.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:libpcm
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:libpcm;
+HopperRequires:
+ProperName:LibPCM
+ProperAuthor:CuriousTorvald
+ProperDescription:PCM decoder for TSVM
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/pcm.mjs

assets/disk0/tvdos/hopper/libpsg.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:libpsg
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:libpsg;
+HopperRequires:
+ProperName:LibPSG
+ProperAuthor:CuriousTorvald
+ProperDescription:Programmable sound generator library for TSVM
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/psg.mjs

assets/disk0/tvdos/hopper/libseqread.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:libseqread
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:libseqread;
+HopperRequires:tvdos 1.*;
+ProperName:LibSeqread
+ProperAuthor:CuriousTorvald
+ProperDescription:Sequentially read files from disk drive
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/seqread.mjs;/tvdos/include/seqreadtape.mjs

assets/disk0/tvdos/hopper/libtaud.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:libtaud
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:libtaud;
+HopperRequires:tvdos 1.*;
+ProperName:LibTaud
+ProperAuthor:CuriousTorvald
+ProperDescription:Helper functions for interaction between Taud format and TSVM Tracker
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/taud.mjs

assets/disk0/tvdos/hopper/libterranbasic.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:libterranbasic
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:libterranbasic;
+HopperRequires:
+ProperName:LibTerranBasic
+ProperAuthor:CuriousTorvald
+ProperDescription:Terran BASIC runtime helper for compiled programs
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/tbas.mjs

assets/disk0/tvdos/hopper/microtone.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:microtone
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:microtone;
+HopperRequires:tvdos 1.*;wintex 1.*;libtaud 1.*;libgl 1.*
+ProperName:Microtone
+ProperAuthor:CuriousTorvald
+ProperDescription:Microtonal tracker for TSVM
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/bin/microtone.alias;/tvdos/bin/taut*

assets/disk0/tvdos/hopper/mirrors.list

@@ -0,0 +1,17 @@
+# Hopper Mirror List
+#
+# One mirror per non-empty, non-comment line.
+# Each entry is the remote URL prefix from which Hopper can fetch
+#     <prefix>mirror_manifest
+#     <prefix>filelist
+#     <prefix><package>.hop.per   (one per row of filelist)
+#
+# `mirror_manifest` declares HopperMirrorName, HopperMirrorMaintainer
+# and HopperMirrorRemotePrefix; `filelist` is CSV of
+#     packagename,version,hoppermanifest-filename
+#
+# Lines starting with `#` and empty lines are ignored.
+# A trailing slash on the prefix is optional; Hopper will add one
+# if missing.
+
+https://raw.githubusercontent.com/curioustorvald/hopper-mirror/refs/heads/master/

assets/disk0/tvdos/hopper/textedit.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:textedit
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:edit;
+HopperRequires:tvdos 1.*
+ProperName:edit.js
+ProperAuthor:CuriousTorvald
+ProperDescription:TVDOS default text editor
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/bin/edit.js

assets/disk0/tvdos/hopper/tvdos.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:tvdos
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:tvdos;
+HopperRequires:
+ProperName:TVDOS
+ProperAuthor:CuriousTorvald
+ProperDescription:TSVM Disk Operating System
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/TVDOS.SYS;/tvdos/hyve.SYS;/tvdos/HSDPADRV.SYS;/tvdos/bin/command.js;/tvdos/sbin/sysctl.js;/tvdos/include/font.mjs;/tvdos/include/keysym.mjs;/tvdos/include/mload.mjs;/tvdos/include/playgui.mjs;/tvdos/include/typesetter.mjs

assets/disk0/tvdos/hopper/wintex.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:wintex
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:wintex;
+HopperRequires:
+ProperName:WinTex
+ProperAuthor:CuriousTorvald
+ProperDescription:TUI window management and renderer
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/include/wintex.mjs

assets/disk0/tvdos/hopper/zfm.hop.per

@@ -0,0 +1,12 @@
+HopperManifestVersion:1
+HopperPackageName:zfm
+HopperPackageVersion:1.0.0
+HopperPackageMaintainer:CuriousTorvald
+HopperProvides:zfm;
+HopperRequires:tvdos 1.*;wintex 1.*
+ProperName:ZFM
+ProperAuthor:CuriousTorvald
+ProperDescription:Z File Manager - Dual-panel file manager for TVDOS
+Licence:MIT
+SupportMe:https://github.com/sponsors/curioustorvald/
+SystemPackagePath:/tvdos/bin/zfm*

assets/disk0/tvdos/include/lfs.mjs

@@ -0,0 +1,171 @@
+/*
+ * lfs.mjs — programmatic extractor for TVDOS Linear File Strip archives.
+ *
+ *   let lfs = require("A:/tvdos/include/lfs.mjs")
+ *
+ *   // Pull one entry out:
+ *   let fd  = lfs.extractOne("A:/path/archive.lfs", "wanted.bin")
+ *   // → file descriptor for $:/TMP/<random>/wanted.bin
+ *
+ *   // Unpack the whole archive:
+ *   let dir = lfs.extractAll("A:/path/archive.lfs")
+ *   // → directory descriptor for $:/TMP/<random>/
+ *
+ * Both functions accept an `autoDecompress` boolean (default true). When
+ * a payload's first four bytes match the gzip (1F 8B 08 xx) or zstd
+ * (28 B5 2F FD) magic, the payload is inflated through gzip.decomp()
+ * before being written. The check is done on the payload bytes — the
+ * archived filename is irrelevant.
+ *
+ * Both functions require a relative-path archive (one produced by
+ * `lfs -c -r`); fully qualified archives carry drive letters that would
+ * not make sense rerooted under $:/TMP.
+ */
+
+const TMP_ROOT     = "$:/TMP"
+const HASH_ALPHABET = "YBNDRFG8EJKMCPQXOTLVWIS2A345H769"
+const HASH_LEN     = 32
+const LFS_HEADER   = "TVDOSLFS\x01"
+const LFS_HEADER_LEN = 16
+const LFS_FLAG_RELATIVE = 0x01
+
+
+function _makeHash(n) {
+    let s = ""
+    const m = HASH_ALPHABET.length
+    for (let i = 0; i < n; i++) s += HASH_ALPHABET[Math.floor(Math.random() * m)]
+    return s
+}
+
+function _isCompressed(s) {
+    if (s.length < 4) return false
+    const b0 = s.charCodeAt(0), b1 = s.charCodeAt(1)
+    const b2 = s.charCodeAt(2), b3 = s.charCodeAt(3)
+    if (b0 === 0x1f && b1 === 0x8b && b2 === 0x08) return true            // gzip
+    if (b0 === 0x28 && b1 === 0xb5 && b2 === 0x2f && b3 === 0xfd) return true  // zstd
+    return false
+}
+
+function _decompress(payload) {
+    // gzip.decomp transparently handles both gzip and zstd; returns Java byte[].
+    return btostr(gzip.decomp(payload))
+}
+
+function _readArchive(lfsPath) {
+    const fd = files.open(lfsPath)
+    if (!fd.exists)     throw new Error("LFS archive not found: " + lfsPath)
+    if (fd.isDirectory) throw new Error("LFS archive is a directory: " + lfsPath)
+
+    const bytes = fd.sread()
+    try { fd.close() } catch (_) {}
+
+    if (bytes.substring(0, LFS_HEADER.length) !== LFS_HEADER)
+        throw new Error("Not an LFS archive: " + lfsPath)
+
+    const flags = bytes.charCodeAt(11)
+    if ((flags & LFS_FLAG_RELATIVE) === 0)
+        throw new Error("LFS archive does not use relative paths: " + lfsPath)
+
+    return bytes
+}
+
+function _allocTmpDir() {
+    const path = TMP_ROOT + "/" + _makeHash(HASH_LEN)
+    const dir  = files.open(path)
+    dir.mkDir()
+    return { fd: dir, path: path }
+}
+
+function _normPath(p) {
+    return p.replace(/\//g, "\\")
+}
+
+function _writeFile(destDirPath, archivePath, payload) {
+    const parts = _normPath(archivePath).split("\\").filter(p => p.length > 0)
+    if (parts.length === 0) return null
+
+    const leaf = parts.pop()
+    let curPath = destDirPath
+    for (let i = 0; i < parts.length; i++) {
+        curPath = curPath + "/" + parts[i]
+        const cur = files.open(curPath)
+        if (!cur.exists) cur.mkDir()
+    }
+    const outfile = files.open(curPath + "/" + leaf)
+    if (!outfile.exists) outfile.mkFile()
+    outfile.swrite(payload)
+    return outfile
+}
+
+
+function extractOne(lfsPath, filename, autoDecompress) {
+    if (autoDecompress === undefined) autoDecompress = true
+    if (filename === undefined || filename === null || filename === "")
+        throw new Error("filename is required")
+
+    const bytes  = _readArchive(lfsPath)
+    const needle = _normPath(filename)
+
+    let curs = LFS_HEADER_LEN
+    while (curs < bytes.length) {
+        const fileType = bytes.charCodeAt(curs)
+        const pathlen  = (bytes.charCodeAt(curs+1) << 8) | bytes.charCodeAt(curs+2)
+        curs += 3
+        const path = bytes.substring(curs, curs + pathlen)
+        curs += pathlen
+        const filelen = (bytes.charCodeAt(curs) << 24)
+                      | (bytes.charCodeAt(curs+1) << 16)
+                      | (bytes.charCodeAt(curs+2) << 8)
+                      |  bytes.charCodeAt(curs+3)
+        curs += 4
+
+        if (_normPath(path) === needle) {
+            let payload = bytes.substring(curs, curs + filelen)
+            if (autoDecompress && _isCompressed(payload)) payload = _decompress(payload)
+
+            const dest  = _allocTmpDir()
+            const leaf  = needle.split("\\").pop()
+            const outfile = files.open(dest.path + "/" + leaf)
+            if (!outfile.exists) outfile.mkFile()
+            outfile.swrite(payload)
+            return outfile
+        }
+
+        curs += filelen
+    }
+
+    throw new Error("File not found in archive: " + filename)
+}
+
+
+function extractAll(lfsPath, autoDecompress) {
+    if (autoDecompress === undefined) autoDecompress = true
+
+    const bytes = _readArchive(lfsPath)
+    const dest  = _allocTmpDir()
+
+    let curs = LFS_HEADER_LEN
+    while (curs < bytes.length) {
+        const fileType = bytes.charCodeAt(curs)
+        const pathlen  = (bytes.charCodeAt(curs+1) << 8) | bytes.charCodeAt(curs+2)
+        curs += 3
+        const path = bytes.substring(curs, curs + pathlen)
+        curs += pathlen
+        const filelen = (bytes.charCodeAt(curs) << 24)
+                      | (bytes.charCodeAt(curs+1) << 16)
+                      | (bytes.charCodeAt(curs+2) << 8)
+                      |  bytes.charCodeAt(curs+3)
+        curs += 4
+
+        let payload = bytes.substring(curs, curs + filelen)
+        if (autoDecompress && _isCompressed(payload)) payload = _decompress(payload)
+        _writeFile(dest.path, path, payload)
+
+        curs += filelen
+    }
+
+    return dest.fd
+}
+
+
+exports = { extractOne, extractAll }

assets/disk0/tvdos/include/net.mjs

@@ -0,0 +1,123 @@
+/*
+ * net.mjs — Internet text-fetch helper for TVDOS
+ *
+ * Wraps the HttpModem peripheral (driven by `_TVDOS.DRV.FS.NET`, see
+ * TVDOS.SYS:1001-1034) behind a small, regular-URL-friendly API. The
+ * helper looks up whichever drive letter the boot probe assigned to the
+ * HTTP modem and translates ordinary URLs (`https://host/path`) into the
+ * scheme-without-double-slash form (`https:host/path`) that the modem
+ * expects on the wire.
+ *
+ * Usage
+ * -----
+ *     let net = require("A:/tvdos/include/net.mjs")
+ *
+ *     if (!net.isAvailable())
+ *         printerrln("No HTTP modem attached")
+ *
+ *     let body = net.fetchText("https://example.com/index.html")
+ *     if (body === null) printerrln("Fetch failed")
+ *     else println(body)
+ */
+
+
+let _cachedDrive = null
+
+/** Scan TVDOS drive table for an HTTP-typed device. Returns the drive
+ *  letter (e.g. "B") or null. */
+function _findHttpDrive() {
+    if (typeof _TVDOS === 'undefined' || !_TVDOS.DRIVEINFO) return null
+    if (_cachedDrive !== null && _TVDOS.DRIVEINFO[_cachedDrive] &&
+        _TVDOS.DRIVEINFO[_cachedDrive].type === 'HTTP')
+        return _cachedDrive
+
+    for (let letter in _TVDOS.DRIVEINFO) {
+        let info = _TVDOS.DRIVEINFO[letter]
+        if (info && info.type === 'HTTP') {
+            _cachedDrive = letter
+            return letter
+        }
+    }
+    return null
+}
+
+/** Convert a regular URL into the form the HTTP modem accepts:
+ *  - strip the `//` between scheme and authority
+ *  - drop any URL fragment
+ *  - assume `https` when no scheme is provided
+ */
+function _normaliseUrl(url) {
+    if (typeof url !== 'string')
+        throw new TypeError("url must be a string")
+    let s = url.trim()
+    if (s.length === 0) throw new Error("url is empty")
+
+    // Drop fragment — the modem speaks to the server, # is client-side.
+    let hash = s.indexOf('#')
+    if (hash >= 0) s = s.substring(0, hash)
+
+    // scheme://host/path  →  scheme:host/path
+    let m = s.match(/^([a-zA-Z][a-zA-Z0-9+.\-]*):\/\/(.*)$/)
+    if (m) return m[1].toLowerCase() + ':' + m[2]
+
+    // Already in scheme:host/path form (the modem's native shape)
+    if (/^[a-zA-Z][a-zA-Z0-9+.\-]*:[^/]/.test(s)) return s
+
+    // No scheme — default to https
+    if (!/^[a-zA-Z][a-zA-Z0-9+.\-]*:/.test(s))
+        return 'https:' + s.replace(/^\/\//, '')
+
+    return s
+}
+
+
+let net = {}
+
+/** Returns the drive letter currently bound to the HTTP modem, or null
+ *  when no such device is attached. */
+net.getHttpDrive = function () {
+    return _findHttpDrive()
+}
+
+/** True iff an HTTP modem is reachable through TVDOS. */
+net.isAvailable = function () {
+    return _findHttpDrive() !== null
+}
+
+/** Translate a URL into the `<drive>:\<modem-url>` form that
+ *  `files.open()` would route through `_TVDOS.DRV.FS.NET`. Useful when
+ *  another component wants the descriptor directly. Throws if no HTTP
+ *  modem is attached. */
+net.toModemPath = function (url) {
+    let drive = _findHttpDrive()
+    if (drive === null) throw new Error("No HTTP modem device is attached")
+    return drive + ':\\' + _normaliseUrl(url)
+}
+
+/** Open a TVDOS file descriptor backed by the HTTP modem for the given
+ *  URL. The descriptor's sread()/bread() trigger the actual fetch.
+ *  Throws if no HTTP modem is attached. */
+net.open = function (url) {
+    return files.open(net.toModemPath(url))
+}
+
+/** Fetch the body of `url` as a string. Returns the response text on
+ *  success, or null when the modem reports a non-zero status (bad URL,
+ *  I/O error, etc.). Throws if no HTTP modem is attached. */
+net.fetchText = function (url) {
+    let fd = net.open(url)
+    let text = fd.sread()
+    try { fd.close() } catch (_) {}
+    return (text === undefined) ? null : text
+}
+
+/** Like fetchText, but throws an Error instead of returning null on
+ *  fetch failure. */
+net.fetchTextOrThrow = function (url) {
+    let body = net.fetchText(url)
+    if (body === null) throw new Error("Failed to fetch URL: " + url)
+    return body
+}
+
+
+exports = net

assets/disk0/tvdos/include/playgui.mjs

@@ -281,9 +281,997 @@ function printTopBar(status, moreInfo) {
     con.move(1, 1)
 }
 
+// ── Audio player visualiser ─────────────────────────────────────────────────
+// Shared by playwav/playmp2/playpcm/playtad.  Design follows
+// `assets/playwav_visualiser_design_2_for_tsvm.md`:
+//   * 3-row ASCII wavescope (mid signal envelope) on rows 3..5
+//   * 22-col progress dashes on the right side of the song-title row
+//   * 24-row XY-scope + wavelet-modulated persistence visualiser on rows 7..30
+//   * stereo energy bar on row 31
+//
+// The visualiser fuses two displays the design doc calls complementary:
+//   * XY-scope geometry (rotated 45° so L plots along the `\` diagonal and R
+//     along `/`) gives spatial motion and stereo image.
+//   * Haar wavelet features (transient / noise / sustain energies) steer the
+//     beam's behaviour — transients evaporate it and emit sparks, sustained
+//     content lets trails breathe longer, mid noise jitters the beam.
+//
+// The wavelet is therefore a *modulator*, not a renderer.  No FFT, no pitch
+// tracking, no per-frame allocation in the hot loop.
+
+const AG_COLS = 80
+const AG_ROWS = 32
+const AG_COL_INSIDE_L = 2
+const AG_COL_INSIDE_R = 79
+const AG_LANE_W       = 78
+
+const AG_ROW_TOP_BORDER = 1
+const AG_ROW_TITLE      = 2
+const AG_ROW_WAVE_TOP   = 3
+const AG_ROW_WAVE_BOT   = 5     // 3-row wavescope
+const AG_ROW_VIS_SEP    = 6
+const AG_ROW_VIS_TOP    = 7
+const AG_ROW_VIS_BOT    = 30    // 24-row wavelet visualiser
+const AG_ROW_STEREO     = 31
+const AG_ROW_BOT_BORDER = 32
+
+const AG_VIS_H = AG_ROW_VIS_BOT - AG_ROW_VIS_TOP + 1   // 24
+const AG_VIS_W = AG_LANE_W                              // 78
+
+// Palette (TSVM 256-colour indices)
+const AG_COL_BG       = 0
+const AG_COL_BORDER   = 250
+const AG_COL_LABEL    = 220
+const AG_COL_DIM      = 235
+const AG_COL_TITLE    = 230
+const AG_COL_VALUE    = 254
+const AG_COL_PROG_ON  = 226     // bright yellow (matches Taud)
+
+// Box-drawing constants (CP437)
+const AG_BX_TL = 0xC9, AG_BX_TR = 0xBB, AG_BX_BL = 0xC8, AG_BX_BR = 0xBC
+const AG_BX_V  = 0xBA, AG_BX_H  = 0xCD
+const AG_SEP_L = 0xC7, AG_SEP_R = 0xB6
+
+// Density stairs for visualiser + stereo bar
+const AG_STAIRS = [0x20, 0xB0, 0xB1, 0xB2, 0xDB]   // ' ', ░, ▒, ▓, █
+
+// Electron-beam colour ramp.  Index 0 = silent (background), last = freshly
+// drawn beam.  Amber-on-black mimics analog vector-scope CRT phosphor — the
+// glyph shape carries the spatial information, the colour ramp carries age.
+const AG_BEAM_PAL = [AG_COL_BG, 94, 130, 166, 220]
+
+// Five wavelet levels (Haar decomp).  These are used only as modulators —
+// they never get rendered as bars.  Indexing:
+//   AG_WL_TRANSIENT — top-octave detail (8 kHz..16 kHz at 32 kHz Fs).
+//                     Spikes on percussion attacks, vocal consonants, cymbals.
+//   AG_WL_NOISE     — upper-mid detail (4..8 kHz).  Drives beam jitter.
+//   AG_WL_BODY      — mid detail (2..4 kHz).
+//   AG_WL_TONAL     — lower-mid detail (1..2 kHz).
+//   AG_WL_BASS      — low detail (0.5..1 kHz).  Slows the decay (sustain).
+const AG_N_BANDS    = 5
+const AG_WL_TRANSIENT = 0
+const AG_WL_NOISE     = 1
+const AG_WL_BODY      = 2
+const AG_WL_TONAL     = 3
+const AG_WL_BASS      = 4
+
+// Stereo bar colour ramp (5 levels) — uses the tonal blue gradient so the
+// stereo strip reads as the "ground" beneath the wavelet cloud.
+const AG_STEREO_COL = [AG_COL_DIM, 17, 33, 75, 117]
+
+// ── State ───────────────────────────────────────────────────────────────────
+//
+// All state lives in module scope so a player just does:
+//     const gui = require('playgui')
+//     gui.audioInit({...})
+//     while (...) { ...; gui.audioFeedPcm(ptr, n); gui.audioRender(); }
+//     gui.audioClose()
+//
+// Multiple concurrent players in one process are not supported — but TVDOS
+// only runs one foreground command at a time, so that's fine.
+
+const AG_SNAPSHOT_N = 1024   // power of 2; covers ~32 ms at 32 kHz
+const ag_snapL = new Float32Array(AG_SNAPSHOT_N)
+const ag_snapR = new Float32Array(AG_SNAPSHOT_N)
+
+const AG_WORK_N = AG_SNAPSHOT_N   // scratch buffers for Haar pyramid
+const ag_workMid = new Float32Array(AG_WORK_N)
+const ag_workTmp = new Float32Array(AG_WORK_N >> 1)
+const ag_bandEnergy = new Float32Array(AG_N_BANDS)
+
+// Sub-500 Hz residual — drops out of the wavelet modulator set on purpose,
+// but we keep its RMS around to drive the bass mark.
+let ag_bassEnergy = 0
+
+// Persistence buffer — float intensity per cell, plus the glyph last written
+// there.  Decay shrinks intensity each frame; new beam samples overwrite the
+// glyph and bump intensity.
+const ag_persist      = new Float32Array(AG_VIS_H * AG_VIS_W)
+const ag_persistGlyph = new Int16Array(AG_VIS_H * AG_VIS_W)
+
+// Skip-redraw cache — only emit a cell when its glyph or colour changes.
+const ag_cellGlyph = new Int16Array(AG_VIS_H * AG_VIS_W).fill(-1)
+const ag_cellFg    = new Int16Array(AG_VIS_H * AG_VIS_W).fill(-1)
+const ag_waveGlyph = new Int16Array(AG_LANE_W * 3).fill(-1)
+const ag_stereoGlyph = new Int16Array(AG_LANE_W).fill(-1)
+const ag_stereoFg    = new Int16Array(AG_LANE_W).fill(-1)
+let ag_lastBassFg    = -1
+
+// Render rate-limiter — playmp2 spins ~32 Hz, playtad ~1 Hz, playwav ~100 Hz
+// at decode time.  Clamp visual refresh to 20 Hz so each caller can spam
+// audioRender() without worrying about pacing.
+let ag_lastRenderNs = 0
+const AG_RENDER_INTERVAL_NS = 50 * 1000 * 1000   // 50 ms
+
+// Latest progress fraction so we redraw the bar only when it changes.
+let ag_lastProgressIdx = -1
+let ag_lastTimeStr = ''
+
+// Init params held for re-use during render.
+let ag_initParams = null
+
+function ag_color(fg, bg) { con.color_pair(fg, bg) }
+function ag_mvprn(row, col, ch) { con.mvaddch(row, col, ch) }
+function ag_mvtext(row, col, s) { con.move(row, col); print(s) }
+
+function ag_pad(n, w) {
+    let s = '' + n
+    while (s.length < w) s = ' ' + s
+    return s
+}
+
+function ag_secToReadable(n) {
+    const mins = ('' + ((n / 60) | 0)).padStart(2, '0')
+    const secs = ('' + (n % 60)).padStart(2, '0')
+    return mins + ':' + secs
+}
+
+function ag_drawSeparator(row, label) {
+    ag_color(AG_COL_BORDER, AG_COL_BG)
+    ag_mvprn(row, 1, AG_SEP_L)
+    for (let x = 2; x < AG_COLS; x++) ag_mvprn(row, x, AG_BX_H)
+    ag_mvprn(row, AG_COLS, AG_SEP_R)
+    if (label) {
+        ag_color(AG_COL_LABEL, AG_COL_BG)
+        ag_mvtext(row, 5, ' ' + label + ' ')
+    }
+}
+
+function ag_drawFrame() {
+    // Top border with embedded format tag.
+    ag_color(AG_COL_BORDER, AG_COL_BG)
+    ag_mvprn(AG_ROW_TOP_BORDER, 1, AG_BX_TL)
+    for (let x = 2; x < AG_COLS; x++) ag_mvprn(AG_ROW_TOP_BORDER, x, AG_BX_H)
+    ag_mvprn(AG_ROW_TOP_BORDER, AG_COLS, AG_BX_TR)
+    if (ag_initParams.tag) {
+        ag_color(AG_COL_LABEL, AG_COL_BG)
+        ag_mvtext(AG_ROW_TOP_BORDER, 4, ' ' + ag_initParams.tag + ' ')
+    }
+
+    // Bottom border with exit hint.
+    ag_color(AG_COL_BORDER, AG_COL_BG)
+    ag_mvprn(AG_ROW_BOT_BORDER, 1, AG_BX_BL)
+    for (let x = 2; x < AG_COLS; x++) ag_mvprn(AG_ROW_BOT_BORDER, x, AG_BX_H)
+    ag_mvprn(AG_ROW_BOT_BORDER, AG_COLS, AG_BX_BR)
+    ag_color(AG_COL_DIM, AG_COL_BG)
+    ag_mvtext(AG_ROW_BOT_BORDER, 4, ' Hold BkSp to exit ')
+
+    // Side bars.
+    ag_color(AG_COL_BORDER, AG_COL_BG)
+    for (let r = 2; r < AG_ROWS; r++) {
+        ag_mvprn(r, 1, AG_BX_V)
+        ag_mvprn(r, AG_COLS, AG_BX_V)
+    }
+
+    // Inner separator over the visualiser canvas.  The wavescope strip sits
+    // flush against the title row — no separator there.
+    ag_drawSeparator(AG_ROW_VIS_SEP, 'VISUALS')
+}
+
+function ag_clearInside(row) {
+    ag_color(AG_COL_DIM, AG_COL_BG)
+    con.move(row, AG_COL_INSIDE_L)
+    print(' '.repeat(AG_LANE_W))
+}
+
+function ag_drawTitle() {
+    ag_clearInside(AG_ROW_TITLE)
+    let title = ag_initParams.title || ''
+    // Reserve 24 cols on the right for time string + progress bar.
+    if (title.length > AG_LANE_W - 26) title = title.substring(0, AG_LANE_W - 29) + '...'
+    ag_color(AG_COL_TITLE, AG_COL_BG)
+    ag_mvtext(AG_ROW_TITLE, AG_COL_INSIDE_L + 1, title)
+}
+
+// Progress: time string + 22-wide dashes ramp (matches playtaud).  Called by
+// the player via audioSetProgress; redraws only when something changed.
+function ag_drawProgress(progress, elapsedSec, totalSec) {
+    const barW = 22
+    const bx0 = AG_COL_INSIDE_R - barW
+    const filled = Math.round(progress * barW)
+
+    const timeStr = ag_secToReadable(elapsedSec) + '/' + ag_secToReadable(totalSec)
+    if (timeStr !== ag_lastTimeStr) {
+        ag_lastTimeStr = timeStr
+        ag_color(AG_COL_VALUE, AG_COL_BG)
+        ag_mvtext(AG_ROW_TITLE, bx0 - timeStr.length - 1, timeStr)
+    }
+
+    if (filled === ag_lastProgressIdx) return
+    ag_lastProgressIdx = filled
+
+    for (let i = 0; i < barW; i++) {
+        const lit = i < filled
+        ag_color(lit ? AG_COL_PROG_ON : AG_COL_DIM, AG_COL_BG)
+        ag_mvprn(AG_ROW_TITLE, bx0 + i, lit ? 0x7C /*│*/ : 0x2E /*.*/)
+    }
+}
+
+// ── PCM ingestion ───────────────────────────────────────────────────────────
+//
+// feedPcm copies the most recent SNAPSHOT_N samples from a PCMu8-stereo-
+// interleaved buffer into our snapshot.  `ptr` can be a positive heap address
+// (LPCM/ADPCM decoded buffer, raw PCM) or a negative peripheral address (TAD
+// decoded buffer, MP2 mediaDecodedBin) — TSVM peripheral memory grows toward
+// 0, so reads use a signed step `vec`.
+
+function audioFeedPcm(ptr, sampleCount) {
+    if (!sampleCount) return
+    const vec = ptr >= 0 ? 1 : -1
+    const inv128 = 1 / 128
+
+    if (sampleCount >= AG_SNAPSHOT_N) {
+        // Take last AG_SNAPSHOT_N samples — discard the rest.
+        const start = sampleCount - AG_SNAPSHOT_N
+        for (let i = 0; i < AG_SNAPSHOT_N; i++) {
+            const off = (start + i) * 2 * vec
+            ag_snapL[i] = ((sys.peek(ptr + off) & 0xFF) - 128) * inv128
+            ag_snapR[i] = ((sys.peek(ptr + off + vec) & 0xFF) - 128) * inv128
+        }
+    } else {
+        // Shift snapshot left by `sampleCount` and append all new samples.
+        const shift = sampleCount
+        const keep  = AG_SNAPSHOT_N - shift
+        for (let i = 0; i < keep; i++) {
+            ag_snapL[i] = ag_snapL[i + shift]
+            ag_snapR[i] = ag_snapR[i + shift]
+        }
+        for (let i = 0; i < shift; i++) {
+            const off = i * 2 * vec
+            ag_snapL[keep + i] = ((sys.peek(ptr + off) & 0xFF) - 128) * inv128
+            ag_snapR[keep + i] = ((sys.peek(ptr + off + vec) & 0xFF) - 128) * inv128
+        }
+    }
+}
+
+// ── Wavelet analysis ───────────────────────────────────────────────────────
+//
+// In-place Haar decomposition.  Five levels on 1024 samples gives band
+// passes (at 32 kHz): [8k..16k], [4k..8k], [2k..4k], [1k..2k], [500..1k].
+// Sub-500 Hz ends up in the approximation and is intentionally dropped —
+// otherwise the bass would dominate every track.
+
+function ag_analyseHaar() {
+    // mid = (L + R) / 2
+    for (let i = 0; i < AG_SNAPSHOT_N; i++) {
+        ag_workMid[i] = (ag_snapL[i] + ag_snapR[i]) * 0.5
+    }
+    let len = AG_SNAPSHOT_N
+    const SQ_HALF = 0.70710678   // 1/sqrt(2) keeps L2 norm
+    for (let lv = 0; lv < AG_N_BANDS; lv++) {
+        const half = len >> 1
+        let sumSq = 0
+        for (let i = 0; i < half; i++) {
+            const a = ag_workMid[i * 2]
+            const b = ag_workMid[i * 2 + 1]
+            const lo = (a + b) * SQ_HALF
+            const hi = (a - b) * SQ_HALF
+            ag_workMid[i] = lo
+            ag_workTmp[i] = hi
+            sumSq += hi * hi
+        }
+        // Higher-freq levels naturally have weaker energy in music; scale
+        // each band by an empirical gain so all five read at comparable
+        // brightness on typical material.
+        const gain = 3.0 + lv * 1.5
+        const rms = Math.sqrt(sumSq / half) * gain
+        ag_bandEnergy[lv] = rms > 1 ? 1 : rms
+        len = half
+    }
+    // Residual approximation in ag_workMid[0..len-1] holds the sub-500 Hz
+    // energy that the modulator pipeline intentionally discards.  Reuse it
+    // to drive the bass mark.
+    let bassSumSq = 0
+    for (let i = 0; i < len; i++) {
+        const v = ag_workMid[i]
+        bassSumSq += v * v
+    }
+    const bassRms = Math.sqrt(bassSumSq / len) * 1.8
+    ag_bassEnergy = bassRms > 1 ? 1 : bassRms
+}
+
+// ── Mini-AAlib (embedded, for the wavescope) ───────────────────────────────
+//
+// Stripped port of `disk0/hopper/include/aa.mjs`, sized to one job: convert a
+// small pixel-space brightness buffer into ASCII glyphs with three monochrome
+// intensities (DIM / NORMAL / BOLD).  No dither.  No brightness / contrast /
+// gamma / inversion.  No REVERSE / SPECIAL / BOLDFONT attribute support.
+// See aa.mjs for the full algorithm, credits (Jan Hubicka & the AA-group,
+// 1997), and the long-form comments — those are not duplicated here.
+//
+// Tables (params + 65536-entry LUT + filltable) are built once on first use
+// from the TSVM 7×14 font ROM, so the wavescope's glyph-selection matches the
+// brightness profile of the cells the hardware text mode actually paints.
+
+const AA_FONT_PATH = "A:/tvdos/tsvm.chr"
+const AA_NORMAL = 0
+const AA_DIM    = 1
+const AA_BOLD   = 2
+const AA_NATTRS = 3
+const AA_NCHARS = 256 * AA_NATTRS
+const AA_DIMMUL  = 5.3
+const AA_BOLDMUL = 2.7
+const AA_MUL = 8
+const AA_VAL = 13                          // uniform-cell threshold
+const AA_PRIORITY = [4, 5, 3]              // NORMAL, DIM, BOLD (matches aalib)
+
+let aa_font = null                         // { width, height, data }
+let aa_params = null                       // Uint16Array((NCHARS+1)*5)
+let aa_table = null                        // Uint16Array(65536)
+let aa_filltable = null                    // Uint16Array(256)
+
+function aa_loadFont() {
+    if (aa_font) return aa_font
+    const fh = files.open(AA_FONT_PATH)
+    if (!fh.exists) throw Error("playgui: font ROM not found: " + AA_FONT_PATH)
+    const blob = fh.bread()
+    const FW = 7, FH = 14, ROM = 1920
+    if (blob.length !== ROM && blob.length !== ROM * 2) {
+        throw Error("playgui: bad font ROM size " + blob.length)
+    }
+    const data = new Uint8Array(256 * FW * FH)
+    const halves = blob.length / ROM
+    const startHalf = (halves === 2) ? 0 : 1
+    for (let h = 0; h < halves; h++) {
+        const romStart = h * ROM
+        const charBase = (startHalf + h) * 128
+        for (let c = 0; c < 128; c++) {
+            const srcBase = romStart + c * FH
+            const dstBase = (charBase + c) * FW * FH
+            for (let r = 0; r < FH; r++) {
+                const b = blob[srcBase + r] & 0xFF
+                for (let x = 0; x < FW; x++) {
+                    data[dstBase + r * FW + x] = ((b >> (6 - x)) & 1) ? 0xFF : 0x00
+                }
+            }
+        }
+    }
+    aa_font = { width: FW, height: FH, data: data }
+    return aa_font
+}
+
+function aa_alowed(i) {
+    const c = i & 0xff
+    const attr = (i >>> 8)
+    if (attr >= AA_NATTRS) return false
+    // printable ASCII, space, or extended (>160) — keep AA_EIGHT chars so the
+    // glyph palette includes the TSVM ROM's box-drawing / shade / dot range.
+    if (!(c >= 33 && c <= 126) && c !== 0x20 && !(c > 160)) return false
+    return true
+}
+
+// (NE, NW, SE, SW) brightness for glyph `code` under `attr`. Quadrant labelling
+// follows aalib's bit-numbering quirk; the LUT lookup later swaps the halves
+// back to natural orientation. See aa.mjs:_glyphValues for the long-form note.
+function aa_glyphValues(code, attr, out) {
+    const fd = aa_font.data
+    const fw = aa_font.width
+    const fh = aa_font.height
+    const base = code * fw * fh
+    const halfW = fw >> 1
+    const halfH = fh >> 1
+    const leftW = halfW
+    const topH  = halfH
+    let v1 = 0, v2 = 0, v3 = 0, v4 = 0
+    for (let r = 0; r < topH; r++) {
+        const rowBase = base + r * fw
+        for (let x = 0; x < leftW; x++) if (fd[rowBase + x]) v2++
+        for (let x = leftW; x < fw;   x++) if (fd[rowBase + x]) v1++
+    }
+    for (let r = topH; r < fh; r++) {
+        const rowBase = base + r * fw
+        for (let x = 0; x < leftW; x++) if (fd[rowBase + x]) v4++
+        for (let x = leftW; x < fw;   x++) if (fd[rowBase + x]) v3++
+    }
+    v1 *= AA_MUL; v2 *= AA_MUL; v3 *= AA_MUL; v4 *= AA_MUL
+    if (attr === AA_DIM) {
+        v1 = (v1 + 1) / AA_DIMMUL
+        v2 = (v2 + 1) / AA_DIMMUL
+        v3 = (v3 + 1) / AA_DIMMUL
+        v4 = (v4 + 1) / AA_DIMMUL
+    } else if (attr === AA_BOLD) {
+        v1 *= AA_BOLDMUL
+        v2 *= AA_BOLDMUL
+        v3 *= AA_BOLDMUL
+        v4 *= AA_BOLDMUL
+    }
+    out[0] = v1; out[1] = v2; out[2] = v3; out[3] = v4
+}
+
+function aa_calcparams() {
+    aa_loadFont()
+    aa_params = new Uint16Array((AA_NCHARS + 1) * 5)
+    const tmp = new Float64Array(4)
+    let ma1 = 0, ma2 = 0, ma3 = 0, ma4 = 0, msum = 0
+    let mi1 = 50000, mi2 = 50000, mi3 = 50000, mi4 = 50000, misum = 50000
+    for (let i = 0; i < AA_NCHARS; i++) {
+        if (!aa_alowed(i)) continue
+        aa_glyphValues(i & 0xff, i >>> 8, tmp)
+        const v1 = tmp[0], v2 = tmp[1], v3 = tmp[2], v4 = tmp[3]
+        if (v1 > ma1) ma1 = v1
+        if (v2 > ma2) ma2 = v2
+        if (v3 > ma3) ma3 = v3
+        if (v4 > ma4) ma4 = v4
+        const s = v1 + v2 + v3 + v4
+        if (s > msum) msum = s
+        if (v1 < mi1) mi1 = v1
+        if (v2 < mi2) mi2 = v2
+        if (v3 < mi3) mi3 = v3
+        if (v4 < mi4) mi4 = v4
+        if (s < misum) misum = s
+    }
+    msum -= misum
+    mi1 = misum / 4; mi2 = misum / 4; mi3 = misum / 4; mi4 = misum / 4
+    ma1 = msum / 4;  ma2 = msum / 4;  ma3 = msum / 4;  ma4 = msum / 4
+    for (let i = 0; i < AA_NCHARS; i++) {
+        aa_glyphValues(i & 0xff, i >>> 8, tmp)
+        const v1r = tmp[0], v2r = tmp[1], v3r = tmp[2], v4r = tmp[3]
+        const sr = v1r + v2r + v3r + v4r
+        let sum = Math.floor((sr - misum) * (1020 / msum) + 0.5)
+        let v1 = Math.floor((v1r - mi1) * (255 / ma1) + 0.5)
+        let v2 = Math.floor((v2r - mi2) * (255 / ma2) + 0.5)
+        let v3 = Math.floor((v3r - mi3) * (255 / ma3) + 0.5)
+        let v4 = Math.floor((v4r - mi4) * (255 / ma4) + 0.5)
+        if (v1 > 255) v1 = 255; else if (v1 < 0) v1 = 0
+        if (v2 > 255) v2 = 255; else if (v2 < 0) v2 = 0
+        if (v3 > 255) v3 = 255; else if (v3 < 0) v3 = 0
+        if (v4 > 255) v4 = 255; else if (v4 < 0) v4 = 0
+        if (sum > 1020) sum = 1020; else if (sum < 0) sum = 0
+        aa_params[i * 5 + 0] = v1
+        aa_params[i * 5 + 1] = v2
+        aa_params[i * 5 + 2] = v3
+        aa_params[i * 5 + 3] = v4
+        aa_params[i * 5 + 4] = sum
+    }
+}
+
+function aa_pow2(x) { return x * x }
+function aa_pos(i1, i2, i3, i4) { return (i1 << 12) + (i2 << 8) + (i3 << 4) + i4 }
+function aa_dist(i1, i2, i3, i4, i5, y1, y2, y3, y4, y5) {
+    return 2 * (aa_pow2(i1 - y1) + aa_pow2(i2 - y2) + aa_pow2(i3 - y3) + aa_pow2(i4 - y4))
+           + aa_pow2(i5 - y5)
+}
+function aa_dist1(i1, i2, i3, i4, i5, y1, y2, y3, y4, y5) {
+    return aa_pow2(i1 - y1) + aa_pow2(i2 - y2) + aa_pow2(i3 - y3) + aa_pow2(i4 - y4)
+           + 2 * aa_pow2(i5 - y5)
+}
+
+function aa_mktable() {
+    if (!aa_params) aa_calcparams()
+    aa_table = new Uint16Array(65536)
+    aa_filltable = new Uint16Array(256)
+    const next = new Int32Array(65536)
+    for (let i = 0; i < 65536; i++) next[i] = i
+    let first = -1, last = -1
+    function add(i) {
+        if (next[i] === i && last !== i) {
+            if (last !== -1) { next[last] = i; last = i }
+            else { last = first = i }
+        }
+    }
+    for (let i = 0; i < AA_NCHARS; i++) {
+        if (!aa_alowed(i)) continue
+        const i1 = aa_params[i * 5 + 0]
+        const i2 = aa_params[i * 5 + 1]
+        const i3 = aa_params[i * 5 + 2]
+        const i4 = aa_params[i * 5 + 3]
+        const i5 = aa_params[i * 5 + 4]
+        const p1 = i1 >> 4, p2 = i2 >> 4, p3 = i3 >> 4, p4 = i4 >> 4
+        const p = aa_pos(p1, p2, p3, p4)
+        if (aa_table[p]) {
+            const ex = aa_table[p]
+            const ex1 = aa_params[ex * 5 + 0]
+            const ex2 = aa_params[ex * 5 + 1]
+            const ex3 = aa_params[ex * 5 + 2]
+            const ex4 = aa_params[ex * 5 + 3]
+            const ex5 = aa_params[ex * 5 + 4]
+            const pp1 = (p1 << 4) | p1
+            const pp2 = (p2 << 4) | p2
+            const pp3 = (p3 << 4) | p3
+            const pp4 = (p4 << 4) | p4
+            const ppsum = pp1 + pp2 + pp3 + pp4
+            const dNew = aa_dist(i1, i2, i3, i4, i5,  pp1, pp2, pp3, pp4, ppsum)
+            const dOld = aa_dist(ex1, ex2, ex3, ex4, ex5,  pp1, pp2, pp3, pp4, ppsum)
+            if (dNew > dOld) continue
+            if (dNew === dOld && AA_PRIORITY[(i >>> 8)] <= AA_PRIORITY[(ex >>> 8)]) continue
+        }
+        aa_table[p] = i
+        add(p)
+    }
+    for (let q = 0; q < 256; q++) {
+        let mindist = Infinity
+        let best = 0
+        for (let i = 0; i < AA_NCHARS; i++) {
+            if (!aa_alowed(i)) continue
+            const d1 = aa_dist1(aa_params[i * 5 + 0], aa_params[i * 5 + 1],
+                                aa_params[i * 5 + 2], aa_params[i * 5 + 3],
+                                aa_params[i * 5 + 4],
+                                q, q, q, q, q * 4)
+            if (d1 < mindist ||
+                (d1 === mindist && AA_PRIORITY[(i >>> 8)] > AA_PRIORITY[(best >>> 8)])) {
+                aa_filltable[q] = i
+                mindist = d1
+                best = i
+            }
+        }
+    }
+    // BFS propagation: claim neighbour slots that we cover better than whoever
+    // got there first.  Lifted verbatim from aamktabl.c via aa.mjs.
+    while (true) {
+        if (last !== -1) next[last] = last
+        else break
+        const blocked = last
+        let i = first
+        if (i === -1) break
+        first = -1; last = -1
+        let prev
+        do {
+            const m0 = (i >> 12) & 15
+            const m1 = (i >> 8) & 15
+            const m2 = (i >> 4) & 15
+            const m3 = i & 15
+            const c = aa_table[i]
+            const cp0 = aa_params[c * 5 + 0]
+            const cp1 = aa_params[c * 5 + 1]
+            const cp2 = aa_params[c * 5 + 2]
+            const cp3 = aa_params[c * 5 + 3]
+            const cp4 = aa_params[c * 5 + 4]
+            for (let dm = 0; dm < 4; dm++) {
+                for (let sgn = -1; sgn <= 1; sgn += 2) {
+                    let n0 = m0, n1 = m1, n2 = m2, n3 = m3
+                    if (dm === 0)      { n0 += sgn; if (n0 < 0 || n0 >= 16) continue }
+                    else if (dm === 1) { n1 += sgn; if (n1 < 0 || n1 >= 16) continue }
+                    else if (dm === 2) { n2 += sgn; if (n2 < 0 || n2 >= 16) continue }
+                    else               { n3 += sgn; if (n3 < 0 || n3 >= 16) continue }
+                    const index = aa_pos(n0, n1, n2, n3)
+                    const ch = aa_table[index]
+                    if (ch === c || index === blocked) continue
+                    let replace = !ch
+                    if (!replace) {
+                        const ii1 = (n0 << 4) | n0
+                        const ii2 = (n1 << 4) | n1
+                        const ii3 = (n2 << 4) | n2
+                        const ii4 = (n3 << 4) | n3
+                        const iisum = ii1 + ii2 + ii3 + ii4
+                        const dNew = aa_dist(ii1, ii2, ii3, ii4, iisum,
+                                             cp0, cp1, cp2, cp3, cp4)
+                        const dOld = aa_dist(ii1, ii2, ii3, ii4, iisum,
+                                             aa_params[ch * 5 + 0],
+                                             aa_params[ch * 5 + 1],
+                                             aa_params[ch * 5 + 2],
+                                             aa_params[ch * 5 + 3],
+                                             aa_params[ch * 5 + 4])
+                        if (dNew < dOld) replace = true
+                    }
+                    if (replace) { aa_table[index] = c; add(index) }
+                }
+            }
+            prev = i
+            i = next[i]
+            next[prev] = prev
+        } while (i !== prev)
+    }
+}
+
+// Render an imgW × imgH brightness buffer (imgW = scrW*2, imgH = scrH*2) into
+// per-cell (glyph, attr) outputs.  No dither, no params.
+function aa_render(img, scrW, scrH, tbOut, attrOut) {
+    if (!aa_table) aa_mktable()
+    const tbl = aa_table
+    const fill = aa_filltable
+    const wi = scrW * 2
+    for (let y = 0; y < scrH; y++) {
+        let pos  = 2 * y * wi
+        let pos1 = y * scrW
+        for (let x = 0; x < scrW; x++) {
+            const i1 = img[pos + 1]       // NE
+            const i2 = img[pos]           // NW
+            const i3 = img[pos + wi + 1]  // SE
+            const i4 = img[pos + wi]      // SW
+            const s = i1 + i2 + i3 + i4
+            const avg = s >> 2
+            let val
+            if (Math.abs(i1 - avg) < AA_VAL &&
+                Math.abs(i2 - avg) < AA_VAL &&
+                Math.abs(i3 - avg) < AA_VAL &&
+                Math.abs(i4 - avg) < AA_VAL) {
+                val = fill[avg]
+            } else {
+                val = tbl[((i2 >> 4) << 12) | ((i1 >> 4) << 8) |
+                          ((i4 >> 4) << 4)  |  (i3 >> 4)]
+            }
+            attrOut[pos1] = val >> 8
+            tbOut[pos1]   = val & 0xff
+            pos  += 2
+            pos1 += 1
+        }
+    }
+}
+
+// ── Wavescope (rows 3..5) ──────────────────────────────────────────────────
+//
+// Peak-detected envelope plotted into a 156×6 pixel buffer (2× cell res),
+// then converted to ASCII glyphs by the mini-AAlib above.  Mid-signal only —
+// stereo info lives on the bottom bar.
+//
+// Three monochrome intensities pick out the wave's body / peaks: DIM cells
+// are the dim trace, NORMAL cells are the bulk of the waveform, BOLD cells
+// land on the brightest patches (full-blocked peaks).  Amber → white ramp
+// mimics phosphor bloom.
+
+const AA_WAVE_W = AG_LANE_W                  // 78 cells
+const AA_WAVE_H = AG_ROW_WAVE_BOT - AG_ROW_WAVE_TOP + 1   // 3 cells
+const AA_WAVE_IW = AA_WAVE_W * 2             // 156 px
+const AA_WAVE_IH = AA_WAVE_H * 2             //   6 px
+
+const ag_waveImg  = new Uint8Array(AA_WAVE_IW * AA_WAVE_IH)
+const ag_waveTb   = new Uint8Array(AA_WAVE_W * AA_WAVE_H)
+const ag_waveAttr = new Uint8Array(AA_WAVE_W * AA_WAVE_H)
+
+// AA_NORMAL=0, AA_DIM=1, AA_BOLD=2  → amber phosphor palette.
+const AG_WAVE_FG = [166, 130, AG_COL_LABEL]
+
+function ag_drawWavescope() {
+    const N  = AG_SNAPSHOT_N
+    const IW = AA_WAVE_IW
+    const IH = AA_WAVE_IH
+    const img = ag_waveImg
+    img.fill(0)
+
+    // Per-pixel-column envelope: vertical line from max to min sample value.
+    const samplesPerCol = N / IW
+    const yScale = (IH - 1) * 0.5
+    for (let c = 0; c < IW; c++) {
+        const s = (c * samplesPerCol) | 0
+        const e = (((c + 1) * samplesPerCol) | 0)
+        let mn = 1.0, mx = -1.0
+        for (let i = s; i < e; i++) {
+            const v = (ag_snapL[i] + ag_snapR[i]) * 0.5
+            if (v < mn) mn = v
+            if (v > mx) mx = v
+        }
+        // [-1, 1] → [0, IH-1]; +1 sits at the top, -1 at the bottom.
+        let yT = ((1 - mx) * yScale + 0.5) | 0
+        let yB = ((1 - mn) * yScale + 0.5) | 0
+        if (yT < 0) yT = 0; else if (yT > IH - 1) yT = IH - 1
+        if (yB < 0) yB = 0; else if (yB > IH - 1) yB = IH - 1
+        for (let y = yT; y <= yB; y++) img[y * IW + c] = 0xFF
+    }
+
+    aa_render(img, AA_WAVE_W, AA_WAVE_H, ag_waveTb, ag_waveAttr)
+
+    // Blit, skipping cells whose packed (attr<<8 | glyph) key is unchanged.
+    for (let r = 0; r < AA_WAVE_H; r++) {
+        for (let c = 0; c < AA_WAVE_W; c++) {
+            const idx = r * AA_WAVE_W + c
+            const att = ag_waveAttr[idx]
+            const ch  = ag_waveTb[idx]
+            const key = (att << 8) | ch
+            if (ag_waveGlyph[idx] === key) continue
+            ag_waveGlyph[idx] = key
+            ag_color(AG_WAVE_FG[att] || AG_COL_LABEL, AG_COL_BG)
+            ag_mvprn(AG_ROW_WAVE_TOP + r, AG_COL_INSIDE_L + c, ch)
+        }
+    }
+}
+
+// ── XY-scope persistence visualiser (rows 7..30) ───────────────────────────
+//
+// 45°-rotated vectorscope, standard convention.  Each PCM sample plots at
+//     col = centre_col + (L − R) · SX
+//     row = centre_row + (L + R) · SY
+// giving the four canonical traces:
+//     in-phase mono (L = R)    → vertical line   ((L−R)=0, (L+R) varies)
+//     out-of-phase mono (L=−R) → horizontal line ((L+R)=0, (L−R) varies)
+//     pure L  (R = 0)          → lower-right diagonal — the `\` axis
+//     pure R  (L = 0)          → lower-left  diagonal — the `/` axis
+// (Positive mono sits below centre because screen row increases downward.)
+// The glyph per cell follows channel dominance, the cell's intensity is
+// bumped on every hit, and a global decay shrinks stale traces back to zero.
+//
+// Wavelet energies are used as *modulators* — the design's central idea:
+//
+//   transient  → faster decay + scattered spark emission
+//   bass/tonal → slower decay (sustained content breathes longer)
+//   noise      → small jitter on plot position (texture fuzz)
+//
+// TSVM terminal cells are ~2:1 (taller than wide); SX is set to ~2×SY so the
+// scope reads roughly circular under steady mono content.
+
+const AG_XY_CX = AG_VIS_W >> 1     // centre column inside visualiser canvas
+const AG_XY_CY = AG_VIS_H >> 1     // centre row
+const AG_XY_SX = 18                // (L−R) → horizontal extent ±36 cells
+const AG_XY_SY = 9                 // (L+R) → vertical   extent ±18 cells
+
+// Bass mark: 2×2 cell indicator pinned to the centre of the vectorscope so
+// the bass "subwoofer" sits underneath the beam's pivot point.  Half-blocks
+// form a compact 16×16-pixel "dot" centred in the 16×32-pixel 2×2 area.
+const AG_BASS_VIS_R0 = AG_XY_CY - 1
+const AG_BASS_VIS_C0 = AG_XY_CX - 1
+const AG_BASS_VIS_R1 = AG_BASS_VIS_R0 + 1
+const AG_BASS_VIS_C1 = AG_BASS_VIS_C0 + 1
+const AG_BASS_SCR_R  = AG_ROW_VIS_TOP + AG_BASS_VIS_R0
+const AG_BASS_SCR_C  = AG_COL_INSIDE_L + AG_BASS_VIS_C0
+
+// Glyphs.
+const AG_G_DOT  = 0xFA  // ·
+const AG_G_BSL  = 0x5C  // \\
+const AG_G_FSL  = 0x2F  // /
+const AG_G_XCR  = 0x58  // X
+const AG_G_SPK  = 0x2A  // *
+const AG_G_HBAR = 0xC4  // ─
+
+function ag_updateXYScope() {
+    // Wavelet-driven modulators, all in [0, 1].
+    const transient = ag_bandEnergy[AG_WL_TRANSIENT]
+    const noise     = ag_bandEnergy[AG_WL_NOISE]
+    const sustain   = ag_bandEnergy[AG_WL_BASS] * 0.6 + ag_bandEnergy[AG_WL_TONAL] * 0.4
+
+    // Decay: base 0.93, longer for sustained content, much shorter for sharp
+    // transients.  Clamped so a screaming hi-hat never freezes the trails and
+    // a deep pad never overflows.
+    let decay = 0.93 + 0.05 * (sustain > 1 ? 1 : sustain)
+                     - 0.10 * (transient > 1 ? 1 : transient)
+    if (decay < 0.72) decay = 0.72
+    if (decay > 0.985) decay = 0.985
+
+    // Decay all cells.
+    for (let i = 0; i < ag_persist.length; i++) {
+        ag_persist[i] *= decay
+    }
+
+    // Plot every sample in the snapshot.  Step 1 keeps lines continuous
+    // visually; with 1024 samples per ~50 ms frame, most cells get multiple
+    // hits and the persistence builds the "beam" silhouette.
+    const SX = AG_XY_SX
+    const SY = AG_XY_SY
+    const cx = AG_XY_CX
+    const cy = AG_XY_CY
+    const jitterAmt = noise * 0.06        // noise-driven beam fuzz
+    const plotBoost = 0.05
+
+    for (let i = 0; i < AG_SNAPSHOT_N; i++) {
+        const L = ag_snapL[i]
+        const R = ag_snapR[i]
+        const mono = L + R                 // vertical axis  ∈ [-2, 2]
+        const side = L - R                 // horizontal axis ∈ [-2, 2]
+        // Wavelet-driven jitter is symmetric — substitute a deterministic
+        // pseudo-random by mixing the snapshot index so we don't churn the
+        // shared Math.random() PRNG 1024× per frame.
+        const jx = (((i * 1103515245 + 12345) & 0xFFFF) / 65536 - 0.5) * jitterAmt
+        const jy = (((i * 1664525     + 1013904223) & 0xFFFF) / 65536 - 0.5) * jitterAmt
+        let col = cx + ((side + jx) * SX) | 0
+        let row = cy + ((mono + jy) * SY) | 0
+        if (col < 0 || col >= AG_VIS_W || row < 0 || row >= AG_VIS_H) continue
+
+        const absL = L < 0 ? -L : L
+        const absR = R < 0 ? -R : R
+        let glyph
+        if (absL + absR < 0.04) {
+            glyph = AG_G_DOT
+        } else if (absL > absR * 1.25) {
+            glyph = AG_G_BSL                 // L-dominant → \
+        } else if (absR > absL * 1.25) {
+            glyph = AG_G_FSL                 // R-dominant → /
+        } else {
+            glyph = AG_G_XCR                 // mixed     → X
+        }
+
+        const idx = row * AG_VIS_W + col
+        let nv = ag_persist[idx] + plotBoost
+        if (nv > 1.0) nv = 1.0
+        ag_persist[idx] = nv
+        ag_persistGlyph[idx] = glyph
+    }
+
+    // Transient spark emission — when high-freq energy peaks, scatter a few
+    // bright `*` glyphs across the canvas.  Cap at ~32 sparks to stay cheap.
+    if (transient > 0.32) {
+        const nSparks = ((transient - 0.32) * 60) | 0
+        for (let s = 0; s < nSparks && s < 32; s++) {
+            const c = (Math.random() * AG_VIS_W) | 0
+            const r = (Math.random() * AG_VIS_H) | 0
+            const idx = r * AG_VIS_W + c
+            if (ag_persist[idx] < 0.85) ag_persist[idx] = 0.85
+            ag_persistGlyph[idx] = AG_G_SPK
+        }
+    }
+}
+
+function ag_drawVisualiser() {
+    for (let r = 0; r < AG_VIS_H; r++) {
+        const rowOff = r * AG_VIS_W
+        const screenY = AG_ROW_VIS_TOP + r
+        const inBassRow = (r === AG_BASS_VIS_R0 || r === AG_BASS_VIS_R1)
+        for (let c = 0; c < AG_VIS_W; c++) {
+            // Bass mark owns its 2×2 cells — let ag_drawBassMark() paint them.
+            if (inBassRow && (c === AG_BASS_VIS_C0 || c === AG_BASS_VIS_C1)) continue
+            const idx = rowOff + c
+            const e = ag_persist[idx]
+            let levelIdx = (e * 5) | 0
+            if (levelIdx > 4) levelIdx = 4
+            if (levelIdx < 0) levelIdx = 0
+            const glyph = (levelIdx === 0) ? 0x20 : ag_persistGlyph[idx]
+            const fg    = AG_BEAM_PAL[levelIdx]
+            if (ag_cellGlyph[idx] === glyph && ag_cellFg[idx] === fg) continue
+            ag_cellGlyph[idx] = glyph
+            ag_cellFg[idx]    = fg
+            ag_color(fg, AG_COL_BG)
+            ag_mvprn(screenY, AG_COL_INSIDE_L + c, glyph)
+        }
+    }
+}
+
+// ── Bass mark (rows 29-30, cols 2-3) ───────────────────────────────────────
+// Brightness-only indicator driven by the sub-500 Hz residual of the Haar
+// pyramid.  Uses indices 1..4 of the beam palette so the dot never falls all
+// the way to background — a quiet track still shows a faint amber ember.
+
+function ag_drawBassMark() {
+    let idx = (ag_bassEnergy * 4) | 0
+    if (idx > 3) idx = 3
+    if (idx < 0) idx = 0
+    const fg = AG_BEAM_PAL[idx + 1]
+    if (fg === ag_lastBassFg) return
+    ag_lastBassFg = fg
+    ag_color(fg, AG_COL_BG)
+    ag_mvprn(AG_BASS_SCR_R,     AG_BASS_SCR_C,     0xDC)
+    ag_mvprn(AG_BASS_SCR_R,     AG_BASS_SCR_C + 1, 0xDC)
+    ag_mvprn(AG_BASS_SCR_R + 1, AG_BASS_SCR_C,     0xDF)
+    ag_mvprn(AG_BASS_SCR_R + 1, AG_BASS_SCR_C + 1, 0xDF)
+}
+
+// ── Stereo energy bar (row 31) ─────────────────────────────────────────────
+//
+// Same idea as playtaud.drawStereo() but driven by raw PCM: for each sample,
+// pan = side/|mid| → bin index, energy = sqrt(|mid|+|side|).  Gaussian-ish
+// 7-cell spread so individual sample clusters read as bars, not single spikes.
+
+function ag_drawStereo() {
+    const W = AG_LANE_W
+    const bins = new Float32Array(W)
+    const N    = AG_SNAPSHOT_N
+
+    for (let i = 0; i < N; i++) {
+        const L = ag_snapL[i]
+        const R = ag_snapR[i]
+        const mid  = (L + R) * 0.5
+        const side = (L - R) * 0.5
+        const absM = mid < 0 ? -mid : mid
+        const absS = side < 0 ? -side : side
+        // Pan estimate, clamped — `side/|mid|` blows up near silence so we
+        // floor the denominator.  This is a coarse stereo image, not a
+        // calibrated readout.
+        let pan = side / (absM + 0.02)
+        if (pan < -1) pan = -1; else if (pan > 1) pan = 1
+        const energy = Math.pow(absM + absS, 0.5)
+        if (energy <= 0) continue
+
+        let col = ((pan + 1) * 0.5 * (W - 1)) | 0
+        if (col < 0) col = 0; else if (col >= W) col = W - 1
+        bins[col] += energy
+        if (col >= 3)     bins[col - 3] += energy * 0.05
+        if (col >= 2)     bins[col - 2] += energy * 0.3
+        if (col >= 1)     bins[col - 1] += energy * 0.75
+        if (col < W - 1)  bins[col + 1] += energy * 0.75
+        if (col < W - 2)  bins[col + 2] += energy * 0.3
+        if (col < W - 3)  bins[col + 3] += energy * 0.05
+    }
+    // Calibrated for "typical" 32 kHz × 1024-sample snapshot at modest level.
+    const norm = 8.0 / N
+    for (let i = 0; i < W; i++) {
+        const v = bins[i] * norm
+        let idx = (v * 1.6) | 0
+        if (idx > 4) idx = 4
+        if (idx < 0) idx = 0
+        const glyph = AG_STAIRS[idx]
+        const fg    = AG_STEREO_COL[idx]
+        if (ag_stereoGlyph[i] === glyph && ag_stereoFg[i] === fg) continue
+        ag_stereoGlyph[i] = glyph
+        ag_stereoFg[i]    = fg
+        ag_color(fg, AG_COL_BG)
+        ag_mvprn(AG_ROW_STEREO, AG_COL_INSIDE_L + i, glyph)
+    }
+}
+
+// ── Public API ─────────────────────────────────────────────────────────────
+//
+// audioInit({ title, tag }): paint the static frame.
+//   title : song title shown on row 2 (left)
+//   tag   : 3-5 char format label embedded in the top border (e.g. "WAV", "MP2")
+//
+// audioFeedPcm(ptr, sampleCount): hand the visualiser a fresh slice of
+//   PCMu8-stereo-interleaved samples (typically the freshly decoded chunk).
+//
+// audioSetProgress(progress, elapsedSec, totalSec): update the title-row
+//   progress bar.  Cheap — only redraws on change.
+//
+// audioRender(): repaint wavescope + visualiser + stereo bar from the latest
+//   snapshot.  Internally rate-limited to ~20 Hz so callers can invoke
+//   liberally without juggling frame timing.
+//
+// audioClose(): restore cursor + move out of the panel for a clean exit.
+
+function audioInit(params) {
+    ag_initParams = params || {}
+    ag_lastRenderNs = 0
+    ag_lastProgressIdx = -1
+    ag_lastTimeStr = ''
+    for (let i = 0; i < ag_snapL.length; i++) { ag_snapL[i] = 0; ag_snapR[i] = 0 }
+    for (let i = 0; i < ag_persist.length; i++) ag_persist[i] = 0
+    ag_persistGlyph.fill(0x20)
+    ag_cellGlyph.fill(-1); ag_cellFg.fill(-1)
+    ag_waveGlyph.fill(-1)
+    ag_stereoGlyph.fill(-1); ag_stereoFg.fill(-1)
+    ag_bassEnergy = 0
+    ag_lastBassFg = -1
+
+    con.curs_set(0)
+    con.clear()
+    ag_drawFrame()
+    ag_drawTitle()
+}
+
+function audioSetProgress(progress, elapsedSec, totalSec) {
+    if (progress < 0) progress = 0; else if (progress > 1) progress = 1
+    ag_drawProgress(progress, elapsedSec | 0, totalSec | 0)
+}
+
+function audioRender() {
+    const now = sys.nanoTime()
+    if (now - ag_lastRenderNs < AG_RENDER_INTERVAL_NS) return
+    ag_lastRenderNs = now
+
+    ag_analyseHaar()
+    ag_updateXYScope()
+    ag_drawWavescope()
+    ag_drawVisualiser()
+    ag_drawBassMark()
+    ag_drawStereo()
+}
+
+function audioClose() {
+    con.move(AG_ROW_BOT_BORDER + 1, 1)
+    con.curs_set(1)
+}
+
+// ── Exit polling ───────────────────────────────────────────────────────────
+// Mirror the Backspace-to-quit convention already in playtaud.
+
+function audioIsExitRequested() {
+    sys.poke(-40, 1)
+    return sys.peek(-41) === 67
+}
+
 exports = {
     clearSubtitleArea,
     displaySubtitle,
     printTopBar,
-    printBottomBar
+    printBottomBar,
+    audioInit,
+    audioFeedPcm,
+    audioSetProgress,
+    audioRender,
+    audioClose,
+    audioIsExitRequested
 }

assets/disk0/tvdos/include/taud.mjs

@@ -83,11 +83,13 @@ function uploadTaudFile(inFile, songIndex, playhead) {
     pos = 8
 
     // -- 3. Parse header ------------------------------------------------------
-    // version(1) + numSongs(1) + compressedSize(4) + rsvd(2) + signature(16) = 24 bytes
+    // magic(8) + version(1) + numSongs(1) + compSize(4) + projOff(4) + signature(14)
+    // = 32 bytes (terranmon.txt §Header).
     let version        = sys.peek(filePtr + pos) & 0xFF;  pos++
     let numSongs       = sys.peek(filePtr + pos) & 0xFF;  pos++
     let compressedSize = _peekU32LE(filePtr, pos);         pos += 4
-    pos += 18  // skip reserved(2) + signature(16)
+    let projOff        = _peekU32LE(filePtr, pos);         pos += 4
+    pos += 14  // signature
     // pos == 32 == TAUD_HEADER_SIZE
 
     if (songIndex < 0 || songIndex >= numSongs) {
@@ -118,7 +120,7 @@ function uploadTaudFile(inFile, songIndex, playhead) {
     let patBinCompSize   = _peekU32LE(filePtr, entryOff + 18)
     let cueSheetCompSize = _peekU32LE(filePtr, entryOff + 22)
 
-    let bpm        = bpmStored + 24
+    let bpm        = bpmStored + 25
     let patsToLoad = numPatsLo | (numPatsHi << 8)
 
     // -- 6. Decompress + upload patterns --------------------------------------
@@ -155,6 +157,50 @@ function uploadTaudFile(inFile, songIndex, playhead) {
     audio.setSongGlobalVolume(playhead, songGlobalVolume)
     audio.setSongMixingVolume(playhead, songMixingVolume)
 
+    // -- 9. Project Data — walk Ixmp blocks for multi-sample instruments -----
+    // Terranmon spec: Project Data starts at `projOff` (zero = absent), magic is
+    // \x1ETaudPrJ + 8 reserved bytes, then a stream of FourCC + Uint32-length
+    // sections. We only consume "Ixmp" here; other sections (PNam, INam, sMet,
+    // etc.) are skipped so the player apps remain free to parse them.
+    if (projOff !== 0 && projOff + 16 <= fileSize) {
+        const projMagic = [0x1E,0x54,0x61,0x75,0x64,0x50,0x72,0x4A]  // \x1ETaudPrJ
+        let prjOk = true
+        for (let i = 0; i < 8; i++) {
+            if ((sys.peek(filePtr + projOff + i) & 0xFF) !== projMagic[i]) { prjOk = false; break }
+        }
+        if (prjOk) {
+            const PATCH_SIZE = 31
+            let p = projOff + 16  // skip magic(8) + reserved(8)
+            while (p + 8 <= fileSize) {
+                const fc = String.fromCharCode(
+                    sys.peek(filePtr + p)     & 0xFF, sys.peek(filePtr + p + 1) & 0xFF,
+                    sys.peek(filePtr + p + 2) & 0xFF, sys.peek(filePtr + p + 3) & 0xFF)
+                const secLen = _peekU32LE(filePtr, p + 4)
+                const payload = p + 8
+                if (payload + secLen > fileSize) break
+                if (fc === 'Ixmp') {
+                    // Each entry: Uint8 instId + Uint24 patchCount + (patchCount × PATCH_SIZE) bytes.
+                    let q = payload
+                    const qEnd = payload + secLen
+                    while (q + 4 <= qEnd) {
+                        const instId   = sys.peek(filePtr + q) & 0xFF; q++
+                        const cntLo    = sys.peek(filePtr + q) & 0xFF; q++
+                        const cntMid   = sys.peek(filePtr + q) & 0xFF; q++
+                        const cntHi    = sys.peek(filePtr + q) & 0xFF; q++
+                        const patchCnt = cntLo | (cntMid << 8) | (cntHi << 16)
+                        const blobLen  = patchCnt * PATCH_SIZE
+                        if (q + blobLen > qEnd) break
+                        let buf = new Array(blobLen)
+                        for (let k = 0; k < blobLen; k++) buf[k] = sys.peek(filePtr + q + k) & 0xFF
+                        audio.uploadInstrumentPatches(instId, buf)
+                        q += blobLen
+                    }
+                }
+                p = payload + secLen
+            }
+        }
+    }
+
 
     fileHandle.close()
     sys.free(filePtr)
@@ -210,7 +256,7 @@ function captureTrackerDataToFile(outFile) {
     // -- 3. BPM / tick-rate / volumes from playhead 0 -------------------------
     let bpm      = audio.getBPM(0)      || 125
     let tickRate = audio.getTickRate(0) || 6
-    let bpmStored = (bpm - 24) & 0xFF
+    let bpmStored = (bpm - 25) & 0xFF
     let songGlobalVolume = audio.getSongGlobalVolume(0)
     let songMixingVolume = audio.getSongMixingVolume(0)
     if (songGlobalVolume === undefined || songGlobalVolume === null) songGlobalVolume = 0x80
@@ -272,7 +318,7 @@ function captureTrackerDataToFile(outFile) {
         (songOffset >>> 24) & 0xFF,
         20,                                    // numVoices
         numPats & 0xFF, (numPats >>> 8) & 0xFF, // numPatterns Uint16 LE
-        bpmStored,                             // BPM with −24 bias
+        bpmStored,                             // BPM with −25 bias
         tickRate,                              // initial tick-rate
         0x00,0xA0,                             // basenote (0xA000 -- C9)
         0x00,0xAC,0x02,0x46,                   // basefreq (8363 Hz)

assets/disk0/tvdos/include/tbas.mjs

@@ -0,0 +1,621 @@
+// Terran BASIC runtime helper for compiled programs
+// Compiled-by: assets/disk0/tbas/compile.js
+// Loaded at runtime by `let bS = require("tbas")`
+//
+// Contract with compiler:
+//   - The compiler has lowered every BASIC expression to a JS expression
+//     that produces the *raw* JS value (number, string, array, ForGen,
+//     function, BasicMemoMonad, …). Builtins take such raw values, NOT
+//     SyntaxTreeReturnObj wrappers.
+//   - Variable reads: bS.__state.vars.X    (key always uppercased)
+//   - Variable writes: bS.__state.vars.X = v
+//   - Control flow (GOTO/GOSUB/RETURN/FOR/NEXT/IF/ON/END/READ/RESTORE/LABEL/DATA)
+//     is *not* exposed here — the compiler emits inline JS that updates the
+//     `pc` and `gosubStack` directly.
+//
+// Naming: BASIC builtins exposed under their UPPERCASE name (bS.PRINT,
+// bS.PLOT, bS.SIN). Compiler-only helpers prefixed with __.
+
+// ---------------------------------------------------------------------------
+// Types & helpers
+// ---------------------------------------------------------------------------
+
+function isNumable(s) {
+    if (Array.isArray(s)) return false
+    if (s === undefined) return false
+    if (typeof s.trim == "function" && s.trim().length == 0) return false
+    return !isNaN(s)
+}
+const tonum = (t) => t * 1.0
+
+function ForGen(s, e, t) {
+    this.start = s
+    this.end = e
+    this.step = t || 1
+    this.current = this.start
+    this.stepsgn = (this.step > 0) ? 1 : -1
+}
+const isGenerator = (o) =>
+    o !== undefined && o !== null &&
+    o.start !== undefined && o.end !== undefined &&
+    o.step !== undefined && o.stepsgn !== undefined
+const genToArray = (gen) => {
+    let a = []
+    let cur = gen.start
+    while (cur * gen.stepsgn + gen.step * gen.stepsgn <= (gen.end + gen.step) * gen.stepsgn) {
+        a.push(cur)
+        cur += gen.step
+    }
+    return a
+}
+const genHasNext = (o) => o.current * o.stepsgn + o.step * o.stepsgn <= (o.end + o.step) * o.stepsgn
+const genGetNext = (gen, mutated) => {
+    if (mutated !== undefined) gen.current = tonum(mutated)
+    gen.current += gen.step
+    return genHasNext(gen) ? gen.current : undefined
+}
+
+function BasicMemoMonad(m) { this.mType = "value"; this.mVal = m }
+function BasicListMonad(m) { this.mType = "list";  this.mVal = [m] }
+function BasicFunSeq(f)    { this.mType = "funseq"; this.mVal = f }
+const isMonad = (o) => o !== undefined && o !== null && o.mType !== undefined
+
+function arrayToString(a) {
+    let acc = ""
+    for (let k = 0; k < a.length; k++) {
+        if (k > 0) acc += ","
+        acc += (Array.isArray(a[k])) ? arrayToString(a[k]) : a[k]
+    }
+    return "{" + acc + "}"
+}
+
+// ---------------------------------------------------------------------------
+// State container
+// ---------------------------------------------------------------------------
+
+const _initialConsts = () => ({
+    NIL: [],
+    PI: Math.PI,
+    TAU: Math.PI * 2,
+    EULER: Math.E,
+    UNDEFINED: undefined,
+    TRUE: true,
+    FALSE: false,
+    // ID is identity-function: emitted as JS arrow when needed
+    ID: (x) => x,
+})
+
+const state = {
+    vars: _initialConsts(),
+    indexBase: 0,
+    dataConsts: [],
+    dataCursor: 0,
+    gotoLabels: {},   // labelName -> [lnum, stmt]
+    lineList: [],     // sorted ascending list of existing source lines (for GOTO snap)
+    rnd: Math.random(),
+    forVar: {},       // varname -> generator|array (the iterable we still owe to FOR/FOREACH)
+    forLnums: {},     // varname -> [lnum, stmt of the FOR/FOREACH header]
+    forStack: [],
+    trace: false,
+    debug: false,
+}
+
+function __reset() {
+    state.vars = _initialConsts()
+    state.indexBase = 0
+    state.dataConsts = []
+    state.dataCursor = 0
+    state.gotoLabels = {}
+    state.lineList = []
+    state.rnd = Math.random()
+    state.forVar = {}
+    state.forLnums = {}
+    state.forStack = []
+}
+
+function __data(values)  { state.dataConsts = values.slice() }
+function __labels(map)   { state.gotoLabels = Object.assign({}, map) }
+function __setLines(arr) { state.lineList = arr.slice() }
+
+// ---------------------------------------------------------------------------
+// Compiler-emitted operator helpers (need behaviour not directly expressible
+// in raw JS without losing semantics)
+// ---------------------------------------------------------------------------
+
+function __add(lh, rh) {
+    return (!isNaN(lh) && !isNaN(rh)) ? (tonum(lh) + tonum(rh)) : (lh + rh)
+}
+function __div(lh, rh)    { if (rh == 0) throw Error("Division by zero"); return lh / rh }
+function __intdiv(lh, rh) { if (rh == 0) throw Error("Division by zero"); return (lh / rh) | 0 }
+function __mod(lh, rh)    { if (rh == 0) throw Error("Division by zero"); return lh % rh }
+function __pow(lh, rh) {
+    let r = Math.pow(lh, rh)
+    if (isNaN(r)) throw Error("Illegal function call")
+    if (!isFinite(r)) throw Error("Division by zero")
+    return r
+}
+
+function __test(v) { return !!v }   // matches builtin TEST: string "false" is truthy
+
+function __dim(dims) {
+    let revdims = dims.slice().reverse()
+    let inner = new Array(revdims[0]).fill(0)
+    for (let k = 1; k < revdims.length; k++) {
+        const sz = revdims[k]
+        const prev = inner
+        inner = new Array(sz).fill(0).map(_ => JSON.parse(JSON.stringify(prev)))
+    }
+    return inner
+}
+
+function __subscriptError(idx, dim) {
+    return Error("Subscript out of range (index " + idx + ", dim " + dim + ")")
+}
+function __arrGet(arr, idx) {
+    let v = arr
+    for (let i = 0; i < idx.length; i++) {
+        if (v === undefined || v === null) throw __subscriptError(idx[i], i)
+        v = v[idx[i] - state.indexBase]
+    }
+    return v
+}
+function __arrSet(arr, idx, value) {
+    let v = arr
+    for (let i = 0; i < idx.length - 1; i++) {
+        if (v === undefined || v === null) throw __subscriptError(idx[i], i)
+        v = v[idx[i] - state.indexBase]
+    }
+    if (v === undefined || v === null) throw __subscriptError(idx[idx.length - 1], idx.length - 1)
+    v[idx[idx.length - 1] - state.indexBase] = value
+}
+
+// FOR / FOREACH setup. Lowered as:
+//   __forSetup(varname, iterable, bodyLnum, bodyStmt)
+// where iterable is a ForGen (FOR…TO…STEP) OR an Array (FOREACH IN…), and
+// (bodyLnum, bodyStmt) is the PC of the statement immediately following the
+// FOR header — i.e. where NEXT should jump back to. The compiler supplies
+// this directly so the state machine doesn't rely on fall-through.
+function __forSetup(varname, iterable, bodyLnum, bodyStmt) {
+    const v = varname.toUpperCase()
+    if (isGenerator(iterable)) {
+        state.vars[v] = iterable.start
+        state.forVar[v] = iterable
+    } else if (Array.isArray(iterable)) {
+        state.vars[v] = iterable[0]
+        state.forVar[v] = iterable.slice(1)  // remainder
+    } else {
+        throw Error("FOR: not a generator or array")
+    }
+    state.forLnums[v] = [bodyLnum, bodyStmt]
+    state.forStack.push(v)
+}
+
+// NEXT [varname]. Without varname, pops the most recent.
+// Returns [lnum, stmt] to jump back to (just-after the FOR header) if more
+// iterations remain, or undefined if the loop is exhausted (caller falls
+// through).
+function __forNext(varname) {
+    let v
+    if (varname === undefined || varname === null) {
+        v = state.forStack.pop()
+    } else {
+        v = varname.toUpperCase()
+        // remove this varname from the stack
+        const idx = state.forStack.lastIndexOf(v)
+        if (idx >= 0) state.forStack.splice(idx, 1)
+    }
+    if (v === undefined) throw Error("NEXT without FOR")
+
+    const it = state.forVar[v]
+    let nextVal
+    if (isGenerator(it)) {
+        nextVal = genGetNext(it, state.vars[v])
+    } else {
+        nextVal = it.shift()
+    }
+
+    if (nextVal !== undefined) {
+        state.vars[v] = nextVal
+        state.forStack.push(v)
+        return state.forLnums[v]   // already the PC of the loop body
+    } else {
+        if (isGenerator(it)) state.vars[v] = it.current
+        return undefined
+    }
+}
+
+function __readData() {
+    const r = state.dataConsts[state.dataCursor++]
+    if (r === undefined) throw Error("Out of DATA")
+    return r
+}
+
+// Resolve a GOTO/GOSUB target — accepts numeric line, label string, or
+// already-evaluated expression. For numeric targets that don't match an
+// existing source line, snap upward to the next one (matches the
+// interpreter's behaviour, where the main loop simply increments lnum until
+// it finds a populated cmdbuf entry).
+function __resolveTarget(t) {
+    if (typeof t === "string" && state.gotoLabels[t] !== undefined) {
+        return state.gotoLabels[t]
+    }
+    let target
+    if (typeof t === "number")    target = t
+    else if (isNumable(t))        target = tonum(t)
+    else throw Error("Invalid jump target: " + t)
+
+    const lines = state.lineList
+    if (lines.length === 0) return [target, 0]
+    // linear scan is fine for the line counts BASIC programs reach
+    for (let i = 0; i < lines.length; i++) {
+        if (lines[i] >= target) return [lines[i], 0]
+    }
+    return [Infinity, 0]
+}
+
+// Invoke a usrdefun (compiled to a JS function), or — when the parser
+// couldn't tell array-indexing apart from function-call (e.g. `A(5)` for an
+// unknown identifier) — index into an array. Used by MAP/FOLD/FILTER, monad
+// operators, and the compiler's default `function` lowering.
+function __runFn(fn, args) {
+    if (typeof fn === "function") return fn.apply(null, args)
+    if (Array.isArray(fn)) return __arrGet(fn, args)
+    if (isMonad(fn) && fn.mType === "funseq") {
+        let arg = args[0]
+        for (let i = 0; i < fn.mVal.length; i++) arg = __runFn(fn.mVal[i], [arg])
+        return arg
+    }
+    throw Error("Not a callable: " + fn)
+}
+
+// ---------------------------------------------------------------------------
+// Operator builtins (where JS doesn't already do the right thing)
+// ---------------------------------------------------------------------------
+
+function _AND(a, b) { if (typeof a !== "boolean" || typeof b !== "boolean") throw Error("Type mismatch"); return a && b }
+function _OR (a, b) { if (typeof a !== "boolean" || typeof b !== "boolean") throw Error("Type mismatch"); return a || b }
+function _NOT(a)    { return !a }
+
+function _CONS(lh, rh) {  // !
+    if (Array.isArray(rh)) return [lh].concat(rh)
+    if (rh && rh.mType === "list") { rh.mVal = [lh].concat(rh.mVal); return rh }
+    throw Error("Type mismatch")
+}
+function _PUSH(lh, rh) {  // ~
+    if (Array.isArray(lh)) return lh.concat([rh])
+    if (lh && lh.mType === "list") { lh.mVal = [lh.mVal].concat([rh]); return lh }
+    throw Error("Type mismatch")
+}
+function _CONCAT(lh, rh) {  // #
+    if (Array.isArray(lh) && Array.isArray(rh)) return lh.concat(rh)
+    if (lh && rh && lh.mType === "list" && rh.mType === "list") return new BasicListMonad(lh.mVal.concat(rh.mVal))
+    throw Error("Type mismatch")
+}
+
+function _TO(from, to)        { return new ForGen(from, to, 1) }
+function _STEP(gen, step) {
+    if (!isGenerator(gen)) throw Error("Type mismatch (STEP)")
+    return new ForGen(gen.start, gen.end, step)
+}
+
+// ---------------------------------------------------------------------------
+// I/O builtins
+// ---------------------------------------------------------------------------
+
+// PRINT(values, seps) — values: array of resolved JS values; seps: array of
+// length values.length-1 with "," | ";" between each consecutive pair.
+// Trailing semicolon? The compiler signals "no newline" by passing a final
+// `null` element in `values` and "noNewline" flag — we use the convention
+// that the LAST entry of `values` being a marker `__noNewline` suppresses
+// the newline (matches basic.js trailing-null behaviour).
+const __PRINT_NONL = Symbol("PRINT_NONL")
+function PRINT(values, seps) {
+    seps = seps || []
+    if (values.length === 0) {
+        println()
+        return
+    }
+    let suppressNewline = false
+    let realLen = values.length
+    if (values[realLen - 1] === __PRINT_NONL) {
+        suppressNewline = true
+        realLen -= 1
+    }
+    for (let i = 0; i < realLen; i++) {
+        if (i >= 1 && seps[i - 1] === ",") print("\t")
+        const v = values[i]
+        let s
+        if (Array.isArray(v))            s = arrayToString(v)
+        else if (v === undefined || v === "") s = ""
+        else if (v.toString !== undefined)    s = v.toString()
+        else                                  s = v
+        print(s)
+    }
+    if (!suppressNewline) println()
+}
+function EMIT(values, seps) {
+    seps = seps || []
+    if (values.length === 0) { println(); return }
+    let suppressNewline = false
+    let realLen = values.length
+    if (values[realLen - 1] === __PRINT_NONL) { suppressNewline = true; realLen -= 1 }
+    for (let i = 0; i < realLen; i++) {
+        if (i >= 1 && seps[i - 1] === ",") print("\t")
+        const v = values[i]
+        if (v === undefined) print("")
+        else if (isNumable(v)) {
+            const c = con.getyx()
+            con.addch(tonum(v))
+            con.move(c[0], c[1] + 1)
+        } else if (v.toString !== undefined) print(v.toString())
+        else print(v)
+    }
+    if (!suppressNewline) println()
+}
+
+function INPUT(promptOrVarname) {
+    print("? ")
+    let r = sys.read().trim()
+    if (!isNaN(r)) r = tonum(r)
+    return r
+}
+function CIN() { return sys.read().trim() }
+
+// ---------------------------------------------------------------------------
+// Numeric builtins
+// ---------------------------------------------------------------------------
+
+const _num = (f) => (x) => { if (!isNumable(x)) throw Error("Type mismatch"); return f(tonum(x)) }
+const _num2 = (f) => (a, b) => {
+    if (!isNumable(a) || !isNumable(b)) throw Error("Type mismatch")
+    return f(tonum(a), tonum(b))
+}
+
+const ABS   = _num(Math.abs)
+const SGN   = _num(x => x > 0 ? 1 : x < 0 ? -1 : 0)
+const INT   = _num(Math.floor)
+const FLOOR = _num(Math.floor)
+const CEIL  = _num(Math.ceil)
+const FIX   = _num(x => x | 0)
+const ROUND = _num(Math.round)
+const SQR   = _num(Math.sqrt)
+const CBR   = _num(Math.cbrt)
+const SIN   = _num(Math.sin)
+const COS   = _num(Math.cos)
+const TAN   = _num(Math.tan)
+const ASN   = _num(Math.asin)
+const ACO   = _num(Math.acos)
+const ATN   = _num(Math.atan)
+const SINH  = _num(Math.sinh)
+const COSH  = _num(Math.cosh)
+const TANH  = _num(Math.tanh)
+const EXP   = _num(Math.exp)
+const LOG   = _num(Math.log)
+const MIN   = _num2((a,b) => a > b ? b : a)
+const MAX   = _num2((a,b) => a < b ? b : a)
+
+function RND(x) {
+    // matches basic.js:1199 — only re-roll when arg !== 0
+    if (!(x === 0)) state.rnd = Math.random()
+    return state.rnd
+}
+
+// ---------------------------------------------------------------------------
+// String builtins
+// ---------------------------------------------------------------------------
+
+function SPC(n)  { return " ".repeat(n) }
+function LEFT(s, n)         { return String(s).substring(0, n) }
+function RIGHT(s, n)        { return String(s).substring(String(s).length - n) }
+function MID(s, start, len) { return String(s).substring(start - state.indexBase, start - state.indexBase + len) }
+function CHR(n)  { return String.fromCharCode(n) }
+
+// ---------------------------------------------------------------------------
+// List builtins
+// ---------------------------------------------------------------------------
+
+function LEN(x)  { if (x === undefined || x.length === undefined) throw Error("Type mismatch"); return x.length }
+function HEAD(x) { if (!x || x.length < 1) throw Error("Type mismatch"); return x[0] }
+function TAIL(x) { if (!x || x.length < 1) throw Error("Type mismatch"); return x.slice(1) }
+function INIT(x) { if (!x || x.length < 1) throw Error("Type mismatch"); return x.slice(0, x.length - 1) }
+function LAST(x) { if (!x || x.length < 1) throw Error("Type mismatch"); return x[x.length - 1] }
+
+function MAP(fn, functor) {
+    if (typeof fn !== "function" && !(isMonad(fn) && fn.mType === "funseq")) throw Error("MAP: not a function")
+    if (isGenerator(functor)) functor = genToArray(functor)
+    if (!Array.isArray(functor)) throw Error("MAP: not iterable")
+    return functor.map(it => __runFn(fn, [it]))
+}
+function FOLD(fn, init, functor) {
+    if (typeof fn !== "function" && !(isMonad(fn) && fn.mType === "funseq")) throw Error("FOLD: not a function")
+    if (isGenerator(functor)) functor = genToArray(functor)
+    if (!Array.isArray(functor)) throw Error("FOLD: not iterable")
+    let akku = init
+    for (let i = 0; i < functor.length; i++) akku = __runFn(fn, [akku, functor[i]])
+    return akku
+}
+function FILTER(fn, functor) {
+    if (typeof fn !== "function" && !(isMonad(fn) && fn.mType === "funseq")) throw Error("FILTER: not a function")
+    if (isGenerator(functor)) functor = genToArray(functor)
+    if (!Array.isArray(functor)) throw Error("FILTER: not iterable")
+    return functor.filter(it => __runFn(fn, [it]))
+}
+
+// Array literal constructor — emitted by the compiler for `[a,b,c]` syntax
+function ARRAY() { return Array.prototype.slice.call(arguments) }
+
+// ---------------------------------------------------------------------------
+// Graphics / system
+// ---------------------------------------------------------------------------
+
+function CLS()   { con.clear() }
+function CLPX()  { graphics.clearPixels(255) }
+function PLOT(x, y, c) { graphics.plotPixel(x, y, c) }
+function GOTOYX(y, x)  { con.move(y + (1 - state.indexBase), x + (1 - state.indexBase)) }
+function TEXTFORE(c)   { print(String.fromCharCode(27, 91) + "38;5;" + (c | 0) + "m") }
+function TEXTBACK(c)   { print(String.fromCharCode(27, 91) + "48;5;" + (c | 0) + "m") }
+function POKE(addr, v) { sys.poke(addr, v) }
+function PEEK(addr)    { return sys.peek(addr) }
+function GETKEYSDOWN() {
+    const keys = []
+    sys.poke(-40, 255)
+    for (let k = -41; k >= -48; k--) keys.push(sys.peek(k))
+    return keys
+}
+
+function CPUT(devnum, msg) { com.sendMessage(devnum, msg); return com.getStatusCode(devnum) }
+function CGET(devnum, ptr) {
+    const msg = com.pullMessage(devnum)
+    const len = msg.length | 0
+    for (let i = 0; i < len; i++) sys.poke(ptr + i, msg.charCodeAt(i))
+    return len
+}
+function CSTA(devnum) { return com.getStatusCode(devnum) }
+
+// ---------------------------------------------------------------------------
+// Type / debug
+// ---------------------------------------------------------------------------
+
+function TYPEOF(v) {
+    if (v === undefined) return "null"
+    if (typeof v === "boolean") return "bool"
+    if (Array.isArray(v)) return "array"
+    if (isGenerator(v)) return "generator"
+    if (isMonad(v)) return v.mType + "-monad"
+    if (typeof v === "function") return "usrdefun"
+    if (isNumable(v)) return "num"
+    if (typeof v === "string") return "string"
+    return typeof v
+}
+
+function OPTIONBASE(n) {
+    if (n != 0 && n != 1) throw Error("Syntax error: OPTIONBASE")
+    state.indexBase = n | 0
+}
+function OPTIONDEBUG(n) { state.debug = (n | 0) === 1 }
+function OPTIONTRACE(n) { state.trace = (n | 0) === 1 }
+
+// ---------------------------------------------------------------------------
+// Monad / functional ops (best-effort port)
+// ---------------------------------------------------------------------------
+
+function MRET(v)  { return new BasicMemoMonad(v) }
+function MLIST(v) { return new BasicListMonad(v) }
+function MJOIN(m) { if (!isMonad(m)) throw Error("Type mismatch"); return m.mVal }
+
+function _BIND(ma, fn) {     // >>=
+    if (!isMonad(ma)) throw Error(">>=: left is not a monad")
+    if (typeof fn !== "function") throw Error(">>=: right is not a function")
+    const mb = __runFn(fn, [ma.mVal])
+    if (!isMonad(mb)) throw Error(">>=: function did not return a monad")
+    return mb
+}
+function _SEQ(ma, mb) {      // >>~
+    if (!isMonad(ma) || !isMonad(mb)) throw Error("Type mismatch")
+    return mb
+}
+function _COMPOSE(fa, fb) {  // .
+    const ma = (typeof fa === "function") ? [fa] : fa.mVal
+    const mb = (typeof fb === "function") ? [fb] : fb.mVal
+    return new BasicFunSeq(mb.concat(ma))
+}
+function _APPLY(fn, value) {  // $
+    return __runFn(fn, [value])
+}
+function _PIPE(value, fn) {   // &
+    return _APPLY(fn, value)
+}
+function _CURRY(fn, value) {  // ~<
+    if (typeof fn !== "function") throw Error("~<: left is not a function")
+    return function() {
+        const rest = Array.prototype.slice.call(arguments)
+        return fn.apply(null, [value].concat(rest))
+    }
+}
+function _SEQAPP(fns, functor) {  // <*>
+    if (!Array.isArray(fns)) throw Error("<*>: first arg must be an array of functions")
+    if (isGenerator(functor)) functor = genToArray(functor)
+    if (!Array.isArray(functor)) throw Error("<*>: not iterable")
+    let ret = []
+    for (let i = 0; i < fns.length; i++) ret = ret.concat(functor.map(it => __runFn(fns[i], [it])))
+    return ret
+}
+function _SEQCURRYMAP(fns, functor) {  // <~>
+    if (typeof fns === "function") fns = [fns]
+    if (!Array.isArray(fns)) throw Error("<~>: first arg must be a function or array of functions")
+    if (isGenerator(functor)) functor = genToArray(functor)
+    if (!Array.isArray(functor)) throw Error("<~>: not iterable")
+    let ret = []
+    for (let i = 0; i < fns.length; i++) ret = ret.concat(functor.map(it => _CURRY(fns[i], it)))
+    return ret
+}
+
+// ---------------------------------------------------------------------------
+// Exports
+// ---------------------------------------------------------------------------
+
+exports = {
+    // state & introspection
+    __state: state, __reset, __data, __labels, __setLines,
+    __PRINT_NONL,
+
+    // operator helpers
+    __add, __div, __intdiv, __mod, __pow, __test,
+    __dim, __arrGet, __arrSet,
+    __forSetup, __forNext, __readData, __resolveTarget,
+    __runFn,
+
+    // type ctors
+    __ForGen: ForGen, __isGenerator: isGenerator, __genToArray: genToArray,
+    __isMonad: isMonad,
+
+    // operators
+    AND: _AND, OR: _OR, NOT: _NOT,
+    UNARYLOGICNOT: _NOT,
+    UNARYBNOT: (a) => ~a,
+    UNARYMINUS: (a) => -a,
+    UNARYPLUS: (a) => +a,
+    BAND: (a,b)=>a&b, BOR: (a,b)=>a|b, BXOR: (a,b)=>a^b,
+    "<<": (a,b)=>a<<b, ">>": (a,b)=>a>>>b,
+    "!": _CONS, "~": _PUSH, "#": _CONCAT,
+    TO: _TO, STEP: _STEP,
+
+    // i/o
+    PRINT, EMIT, INPUT, CIN,
+
+    // numeric
+    ABS, SGN, INT, FLOOR, CEIL, FIX, ROUND, SQR, CBR,
+    SIN, COS, TAN, ASN, ACO, ATN, SINH, COSH, TANH,
+    EXP, LOG, MIN, MAX, RND,
+
+    // strings
+    SPC, LEFT, RIGHT, MID, CHR,
+
+    // lists
+    LEN, HEAD, TAIL, INIT, LAST, MAP, FOLD, FILTER,
+    ARRAY,
+
+    // graphics / system
+    CLS, CLPX, PLOT, GOTOYX, TEXTFORE, TEXTBACK,
+    POKE, PEEK, GETKEYSDOWN, CPUT, CGET, CSTA,
+
+    // type / option
+    TYPEOF, OPTIONBASE, OPTIONDEBUG, OPTIONTRACE,
+
+    // monads / functional
+    MRET, MLIST, MJOIN,
+    ">>=": _BIND, ">>~": _SEQ,
+    ".":   _COMPOSE, "$": _APPLY, "&": _PIPE, "~<": _CURRY,
+    "<*>": _SEQAPP, "<$>": MAP, "<~>": _SEQCURRYMAP,
+
+    // misc
+    DO: function() { return arguments[arguments.length - 1] },
+    CLEAR: function() { state.vars = _initialConsts() },
+    END: function() { /* compiler emits pc=[Infinity,0] */ },
+    LABEL: function() { /* harvested at compile time */ },
+    DATA:  function() { /* harvested at compile time */ },
+    // DIM as an expression (e.g. `WS = DIM(H, V)`): allocate and return a
+    // freshly zero-filled N-D array. The statement form `DIM A(H, V)` is
+    // compiled inline and never reaches this entry.
+    DIM: function() { return __dim(Array.prototype.slice.call(arguments)) },
+}

assets/disk0/tvdos/include/typesetter.mjs

@@ -0,0 +1,331 @@
+/*
+ * typesetter.mjs - Rich-text typesetter for TVDOS console output.
+ *
+ * Wraps and aligns text using a tiny markup language. Originally lifted
+ * out of taut_helpmsg.js so other tools (motd, help popups, ...) can
+ * share the same formatter.
+ *
+ * Markup
+ * ------
+ *   <b>...</b>   emphasised foreground colour
+ *   <c>...</c>   centre-align this source line
+ *   <r>...</r>   right-align this source line
+ *   <l>...</l>   left-align this source line
+ *   <o>...</o>   virtual typesetting box. Left anchor is the cursor
+ *                column at the open tag, right anchor is the wrap edge.
+ *   default alignment is fully justified (override per-call via opts).
+ *
+ * Entities
+ * --------
+ *   &microtone;          "Microtone" wordmark
+ *   &bul; &ddot; &mdot;  bullet glyphs
+ *   &updn; &udlr;        arrow glyphs
+ *   &keyoffsym; &notecutsym;
+ *   &demisharp; &sharp; &sesquisharp; &doublesharp; &triplesharp; &quadsharp;
+ *   &demiflat; &flat; &sesquiflat; &doubleflat; &tripleflat; &quadflat;
+ *   &accuptick; &accdntick; &accupup; &accdndn;
+ *   &nbsp;               non-breaking space
+ *   &shy;                soft hyphen (currently dropped)
+ *   &lt; &gt;            literal angle brackets
+ *
+ * Usage
+ * -----
+ *   let ts = require("typesetter")
+ *   let lines = ts.typeset(text, width)            // array of width-wide strings
+ *   let lines = ts.typeset(text)                   // width = rest of current row
+ *   let lines = ts.typeset(text, width, { defaultAlign: 'l' })
+ */
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Palette / ANSI helpers
+///////////////////////////////////////////////////////////////////////////////
+
+const COL_TEXT      = 239 // popup body default (== colWHITE)
+const COL_EMPH      = 230 // <b>...</b> highlight (== colVoiceHdr)
+const COL_BRAND     = 211 // first half of "Microtone"
+const COL_BRAND_DIM = 239 // second half of "Microtone"
+
+const fgEsc = (n) => `\x1B[38;5;${n}m`
+const ESC_DEFAULT = fgEsc(COL_TEXT)
+const ESC_EMPH    = fgEsc(COL_EMPH)
+const MICROTONE   = `${fgEsc(COL_BRAND)}Micro${fgEsc(COL_BRAND_DIM)}tone${ESC_DEFAULT}`
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Entity expansion
+///////////////////////////////////////////////////////////////////////////////
+
+// Replace &xxx; entities with their final printable representations.
+function expandEntities(s) {
+    return s
+        .replaceAll('&microtone;',  MICROTONE)
+        .replaceAll('&bul;',        '\u00F9')
+        .replaceAll('&ddot;',       '\u008419u')
+        .replaceAll('&mdot;',       '\u00FA')
+        .replaceAll('&updn;',       '\u008418u')
+        .replaceAll('&udlr;',       '\u008428u\u008429u')
+        .replaceAll('&keyoffsym;',  '\u00A0\u00B1\u00B1\u00A1')
+        .replaceAll('&notecutsym;', '\u00A4\u00A4\u00A4\u00A4')
+        .replaceAll('&nbsp;',       '\u007F')
+        .replaceAll('&shy;',        '')
+        .replaceAll('&lt;',        '<')
+        .replaceAll('&gt;',        '>')
+        .replaceAll('&demisharp;',   '\u0080\u0081')
+        .replaceAll('&sharp;',       '\u0082\u0083')
+        .replaceAll('&sesquisharp;', '\u0084132u\u0085')
+        .replaceAll('&doublesharp;', '\u0086\u0087')
+        .replaceAll('&triplesharp;', '\u0088\u0089')
+        .replaceAll('&quadsharp;',   '\u008A\u008B')
+        .replaceAll('&demiflat;',    '\u008C\u008D')
+        .replaceAll('&flat;',        '\u008E\u008F')
+        .replaceAll('&sesquiflat;',  '\u0090\u0091')
+        .replaceAll('&doubleflat;',  '\u0092\u0093')
+        .replaceAll('&tripleflat;',  '\u0094\u0095')
+        .replaceAll('&quadflat;',    '\u0096\u0097')
+        .replaceAll('&accuptick;',    '\u009A')
+        .replaceAll('&accdntick;',    '\u009B')
+        .replaceAll('&accupup;',    '\u009C')
+        .replaceAll('&accdndn;',    '\u009D')
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Tokeniser
+///////////////////////////////////////////////////////////////////////////////
+
+// Tokenise a (post-entity-expansion) line. Returns an array of:
+//   {type:'word',   text:String, w:int}  - non-breakable run of visible chars (may carry ANSI escapes)
+//   {type:'sp'}                          - a single soft space (eligible for break/expansion)
+//   {type:'anchor', open:Boolean}        - <o>/</o> markers (zero width)
+//
+// Width accounting:
+//   - ANSI escapes (`\x1B[...m`)         : 0 visible chars
+//   - TSVM unicode escapes (`\u0084..u`) : 1 visible char
+//   - non-breaking space (\u007F)        : 1 visible char (consumed as part of a word)
+//   - soft hyphen (\u00AD)               : dropped (not implemented as a break point)
+//   - everything else                    : 1 visible char
+function tokenise(line) {
+    const tokens = []
+    let buf = ''
+    let bufW = 0
+    let i = 0
+
+    const flushWord = () => {
+        if (buf.length > 0) {
+            tokens.push({type: 'word', text: buf, w: bufW})
+            buf = ''
+            bufW = 0
+        }
+    }
+
+    while (i < line.length) {
+        // inline tags (case-sensitive for <b>, case-insensitive for <o>)
+        if (line.slice(i, i + 3) === '<b>')  { buf += ESC_EMPH;    i += 3; continue }
+        if (line.slice(i, i + 4) === '</b>') { buf += ESC_DEFAULT; i += 4; continue }
+        const head3 = line.slice(i, i + 3).toLowerCase()
+        const head4 = line.slice(i, i + 4).toLowerCase()
+        if (head3 === '<o>')  { flushWord(); tokens.push({type: 'anchor', open: true});  i += 3; continue }
+        if (head4 === '</o>') { flushWord(); tokens.push({type: 'anchor', open: false}); i += 4; continue }
+
+        const c  = line[i]
+        const cc = line.charCodeAt(i)
+
+        if (cc === 0x1B) {
+            // pre-existing ANSI escape - copy verbatim, zero visible width
+            const m = line.indexOf('m', i)
+            const end = (m < 0) ? line.length : m + 1
+            buf += line.slice(i, end)
+            i = end
+        }
+        else if (cc === 0x84) {
+            // TSVM \u0084<digits>u escape - copy verbatim, one visible char
+            const u = line.indexOf('u', i)
+            const end = (u < 0) ? line.length : u + 1
+            buf += line.slice(i, end)
+            bufW += 1
+            i = end
+        }
+        else if (c === ' ') {
+            flushWord()
+            tokens.push({type: 'sp'})
+            i += 1
+        }
+        else if (cc === 0x00AD) {
+            // soft hyphen: drop (no break-point handling for now)
+            i += 1
+        }
+        else {
+            buf += c
+            bufW += 1
+            i += 1
+        }
+    }
+    flushWord()
+    return tokens
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Line builder
+///////////////////////////////////////////////////////////////////////////////
+
+// Build wrapped lines from a token stream then format each one according to alignment.
+// Returns an array of strings, each exactly `width` visible chars wide (padded with
+// trailing spaces) so the caller can blit them without further math.
+function wrapAndAlign(tokens, width, alignment) {
+    const lines = [] // each: {tokens, indent, contentW}
+    let curTokens = []
+    let curW = 0
+    let curIndent = 0
+    let nextIndent = 0 // indent the *next* flushed line should use
+
+    const flushLine = () => {
+        // strip trailing soft spaces
+        while (curTokens.length > 0 && curTokens[curTokens.length - 1].type === 'sp') {
+            curTokens.pop()
+            curW -= 1
+        }
+        lines.push({tokens: curTokens, indent: curIndent, contentW: curW})
+        curTokens = []
+        curW = 0
+        curIndent = nextIndent
+    }
+
+    for (const tok of tokens) {
+        if (tok.type === 'anchor') {
+            // anchor opens at the current visible column (accounting for indent)
+            if (tok.open) nextIndent = curIndent + curW
+            else          nextIndent = 0
+            continue
+        }
+
+        if (tok.type === 'sp') {
+            // ignore leading soft spaces on a fresh line
+            if (curW === 0) continue
+            // hard wrap if the line is already at the right edge
+            if (curIndent + curW + 1 > width) { flushLine(); continue }
+            curTokens.push(tok)
+            curW += 1
+            continue
+        }
+
+        // word
+        const tw = tok.w
+        if (curIndent + curW + tw > width) {
+            flushLine()
+            // word too wide for the wrapped line: emit it on its own row (possibly clipped by terminal)
+            if (curIndent + tw > width) {
+                curTokens.push(tok)
+                curW += tw
+                flushLine()
+                continue
+            }
+        }
+        curTokens.push(tok)
+        curW += tw
+    }
+
+    if (curTokens.length > 0 || lines.length === 0) flushLine()
+
+    return lines.map((line, i) => formatLine(line, width, alignment, i === lines.length - 1))
+}
+
+function formatLine(line, totalWidth, alignment, isLast) {
+    if (line.tokens.length === 0) return ' '.repeat(totalWidth)
+
+    const indent    = ' '.repeat(line.indent)
+    const remaining = totalWidth - line.indent - line.contentW
+    const pad       = (n) => (n > 0) ? ' '.repeat(n) : ''
+    const flatText  = () => line.tokens.map(t => (t.type === 'sp') ? ' ' : t.text).join('')
+
+    if (alignment === 'c') {
+        const left = remaining >> 1
+        return indent + pad(left) + flatText() + pad(remaining - left)
+    }
+    if (alignment === 'r') return indent + pad(remaining) + flatText()
+    if (alignment === 'l') return indent + flatText() + pad(remaining)
+
+    // justified: only expand spaces when there's slack and we're not on the
+    // last (or single) wrapped line
+    if (isLast || remaining <= 0) return indent + flatText() + pad(remaining)
+
+    const spaceCount = line.tokens.reduce((n, t) => n + (t.type === 'sp' ? 1 : 0), 0)
+    if (spaceCount === 0) return indent + flatText() + pad(remaining)
+
+    const baseExtra = (remaining / spaceCount) | 0
+    let leftover    = remaining - baseExtra * spaceCount
+
+    let out = indent
+    for (const tok of line.tokens) {
+        if (tok.type === 'sp') {
+            const extra = baseExtra + (leftover > 0 ? 1 : 0)
+            if (leftover > 0) leftover -= 1
+            out += ' '.repeat(1 + extra)
+        } else {
+            out += tok.text
+        }
+    }
+    return out
+}
+
+// Process a single source line: peel a leading <c>/<r>/<l> alignment tag (if present),
+// strip its matching close tag, then tokenise + wrap.
+function typesetSourceLine(line, width, defaultAlign) {
+    if (line.length === 0) return [' '.repeat(width)]
+
+    let alignment = defaultAlign || 'j' // justified default
+    const startMatch = line.match(/^<([crl])>/i)
+    if (startMatch) {
+        alignment = startMatch[1].toLowerCase()
+        line = line.slice(startMatch[0].length)
+        const closeRe = new RegExp(`</${alignment}>$`, 'i')
+        line = line.replace(closeRe, '')
+    }
+
+    const tokens = tokenise(line)
+    return wrapAndAlign(tokens, width, alignment)
+}
+
+function typesetText(text, width, defaultAlign) {
+    text = expandEntities(text)
+    const out = []
+    for (const srcLine of text.split('\n')) {
+        for (const outLine of typesetSourceLine(srcLine, width, defaultAlign)) out.push(outLine)
+    }
+    return out
+}
+
+// Convenience entry: `typeset(text)` defaults the wrap width to "rest of current row".
+// `opts` may be `{ defaultAlign: 'l' | 'c' | 'r' | 'j' }`.
+function typeset(text, customWidth, opts) {
+    let typesetWidth = customWidth
+    if (typesetWidth === undefined) {
+        const SCRW = con.getmaxyx()[1]
+        const currentPosX = con.getyx()[1] // 1-indexed
+        typesetWidth = SCRW - currentPosX + 1
+    }
+    let defaultAlign = (opts && opts.defaultAlign) || 'j'
+    return typesetText(text, typesetWidth, defaultAlign)
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Module exports
+///////////////////////////////////////////////////////////////////////////////
+
+exports = {
+    typeset,
+    typesetText,
+    typesetSourceLine,
+    tokenise,
+    expandEntities,
+    fgEsc,
+    COL_TEXT,
+    COL_EMPH,
+    COL_BRAND,
+    COL_BRAND_DIM,
+    ESC_DEFAULT,
+    ESC_EMPH,
+    MICROTONE,
+}

assets/disk0/tvdos/include/wintex.mjs

@@ -65,12 +65,12 @@ class WindowObject {
             }
             if (this.titleRight !== undefined) {
                 let tt = ''+this.titleRight
-                con.move(this.y, this.x + this.width - tt.length - 2)
+                con.move(this.y + this.height - 1, this.x + this.width - tt.length - 2)
                 print(`\x84${charset[4]}u`)
                 if (this.titleBackRight !== undefined) print(`\x1B[48;5;${this.titleBackRight}m`)
                 print(`\x1B[38;5;${colourText}m${tt}`)
                 if (this.titleBackRight !== undefined) print(`\x1B[48;5;${oldBack}m`)
-                print(`\x1B[38;5;${colour}m\x84${charset[1]}u`)
+                print(`\x1B[38;5;${colour}m\x84${charset[3]}u`)
             }
 
 
@@ -180,4 +180,769 @@ function scrollHorz(dx, stringSize, stringViewSize, currentCursorPos, currentScr
     return [currentCursorPos, currentScrollPos]
 }
 
-exports = { WindowObject, scrollVert, scrollHorz }
+// ---------------------------------------------------------------------------
+// Modal dialog with optional body text, input fields, a scrollable selection
+// list, and OK/Cancel-style buttons. Layout from top to bottom:
+//   title bar, message, fields, list, buttons.
+//
+// opts = {
+//   title:   string,
+//   message: string | string[]?,             -- optional body text drawn above fields/list
+//   drawFrame: function(wo)?,                -- override for the window-frame painter;
+//                                               same contract as WindowObject's
+//                                               `drawFrame` slot. Useful when the caller
+//                                               wants its own border / title styling.
+//
+//   fields:  [{label, initial?, width, maxLength?}, ...] -- omit / [] for no input
+//                                               field. Label does NOT get auto-colon.
+//                                               `maxLength` caps insertable chars
+//                                               (default: width * 4).
+//
+//   list: {                                  -- optional vertical selection list
+//     items:     [{label, ...}, ...],        -- arbitrary user objects; only `label`
+//                                               is read by the default renderer.
+//     height:    number,                     -- visible row count.
+//     width:     number?,                    -- inner width override (default: popup w-4).
+//     cursor:    number?,                    -- initial cursor row (default: first selectable).
+//     selectable: function(item, i)->bool?,  -- default: every item selectable. Non-
+//                                               selectable rows are skipped by arrow keys.
+//                                               When NO row is selectable, arrow / PgUp
+//                                               / PgDn scroll the view instead.
+//     renderItem: function(ctx)?,            -- per-row painter; ctx exposes
+//                                               { y, x, w, item, idx, isCursor, focused,
+//                                                 listBg, selBg, fg, hlFg, dimFg }.
+//                                               Default prints `item.label`.
+//     onActivate: function(item, i, key)?,   -- fired on Enter ('\n') / Space (' ')
+//                                               / left-click ('click'); return an
+//                                               action string to close the dialog,
+//                                               or null to stay open.
+//     showScrollbar: bool?,                  -- default: auto (true when overflowing).
+//     scrollbarChars: number[6]?,            -- glyph codes for the scrollbar:
+//                                               [troughTopEmpty, troughMidEmpty,
+//                                                troughBotEmpty, troughTopFilled,
+//                                                troughMidFilled, troughBotFilled].
+//                                               Default [0xBA,0xBA,0xBA,0xDB,0xDB,0xDB]
+//                                               (CP437-safe). Callers with a custom
+//                                               charset (e.g. taut) pass their own.
+//     drawWell: bool?,                       -- draw the list background
+//     bg: number?,                           -- list background colour (default 242).
+//   },
+//
+//   buttons: [{label, action, default?}, ...] -- defaults to [OK, Cancel] (+ Delete
+//            if `allowDelete:true`)
+//   allowDelete: bool,                       -- inserts a Delete button (fsh compat)
+//   colours: {fg?, bg?, fieldBg?, dimFg?, hlFg?, focusBg?, listBg?, listSelBg?}
+//                                            -- per-call overrides
+//   disableKeyRepeat: bool,               -- when true, key won't repeat when held down
+//   onKey: function(ks, shiftDown, ctx)?,    -- escape hatch for callers that need
+//                                               extra key bindings. Runs BEFORE the
+//                                               built-in handlers. Return true to
+//                                               consume the key. `ctx` exposes
+//                                               { render, close(result),
+//                                                 getListCursor, setListCursor }.
+// }
+//
+// Returns {action, values, listCursor, listItem}: `action` is the chosen button's
+// `action` or the value returned from `onActivate` (default "ok"/"cancel"/"delete"),
+// or "cancel" on Esc; `values` is the array of field strings in field order;
+// `listCursor` is the final cursor index (-1 if there is no list); `listItem` is
+// the item at that index.
+//
+// Behaviour:
+//   - Tab / Shift+Tab and arrow Down / Up cycle focus across fields, list, and buttons.
+//     Inside the list, arrow Up / Down move the cursor between selectable rows;
+//     PgUp/PgDn move a page; Home/End jump to the first/last selectable row.
+//   - Left / Right inside a field move the caret; on the list or a button they cycle focus.
+//   - Home / End jump to start / end of the focused field.
+//   - Enter on a field jumps to the next field, then to the first button. Enter
+//     or Space on a button activates it. Enter or Space on a list row invokes
+//     `onActivate(item, idx, key)`; if that returns a string, the dialog closes
+//     with that action.
+//   - Insert at caret. Backspace deletes left of caret; Forward-Del deletes right.
+//   - Blinking caret (`con.curs_set(1)`) is positioned on the focused field and
+//     hidden when the list or a button has focus.
+//   - Mouse: left-click on a button activates it; click on a field puts focus
+//     on that field and positions the caret under the click; click on a list row
+//     moves the cursor (and fires `onActivate` if defined); mouse-wheel inside the
+//     list scrolls it. Mouse hover on a button moves focus to it (the same focus
+//     the keyboard uses).
+const _dialogScreen = con.getmaxyx()
+const _dialogPixDim = graphics.getPixelDimension()
+const _CELL_PW = (_dialogPixDim[0] / _dialogScreen[1]) | 0
+const _CELL_PH = (_dialogPixDim[1] / _dialogScreen[0]) | 0
+function _pxToCell(px, py) { return [(py / _CELL_PH | 0) + 1, (px / _CELL_PW | 0) + 1] }
+
+function showDialog(opts) {
+    const fields  = opts.fields || []
+    const values  = fields.map(f => (f.initial == null) ? '' : ('' + f.initial))
+    const cursors = values.map(v => v.length)
+
+    let oldFG = con.get_color_fore()
+    let oldBG = con.get_color_back()
+
+    let buttons
+    if (opts.buttons) {
+        buttons = opts.buttons
+    } else {
+        buttons = [{label: 'OK', action: 'ok', default: true}]
+        if (opts.allowDelete) buttons.push({label: 'Delete', action: 'delete'})
+        buttons.push({label: 'Cancel', action: 'cancel'})
+    }
+
+    const title = opts.title || ''
+    const message = opts.message
+    const messageLines = !message ? []
+        : Array.isArray(message) ? message
+        : ('' + message).split('\n')
+
+    const list = opts.list || null
+    const drawWell = list?.drawWell ?? true
+    const c         = opts.colours || {}
+    const fg        = (c.fg        != null) ? c.fg        : 254
+    const bg        = (c.bg        != null) ? c.bg        : 244
+    const fieldBg   = (c.fieldBg   != null) ? c.fieldBg   : 240
+    const dimFg     = (c.dimFg     != null) ? c.dimFg     : 249
+    const hlFg      = (c.hlFg      != null) ? c.hlFg      : 240
+    const focusBg   = (c.focusBg   != null) ? c.focusBg   : 253
+    const listBg    = (c.listBg    != null) ? c.listBg    : (drawWell) ? 243 : bg
+    const listSelBg = (c.listSelBg != null) ? c.listSelBg : focusBg
+
+    // List state
+    const listItems = list ? (list.items || []) : []
+    const listSelectable = list && list.selectable ? list.selectable : (() => true)
+    const listHeight     = list ? (list.height || Math.min(8, listItems.length)) : 0
+    const hasList        = !!list
+    const listOnActivate = list ? list.onActivate : null
+    const listBgColour   = (list && list.bg != null) ? list.bg : listBg
+    // Scrollbar glyphs: [trough top/mid/bottom empty, then top/mid/bottom filled].
+    // Default is CP437-safe (0xBA track, 0xDB thumb); callers with their own
+    // charset (e.g. taut's 0xBA..0xBF) pass a 6-item override.
+    const listScrollbarChars = (list && Array.isArray(list.scrollbarChars) && list.scrollbarChars.length >= 6)
+        ? list.scrollbarChars
+        : [0xBA, 0xBA, 0xBA, 0xDB, 0xDB, 0xDB]
+    function firstSelectable(from, dir) {
+        if (!hasList || listItems.length === 0) return -1
+        let i = from
+        for (let n = 0; n < listItems.length; n++) {
+            if (i >= 0 && i < listItems.length && listSelectable(listItems[i], i)) return i
+            i += dir
+            if (i < 0) i = listItems.length - 1
+            if (i >= listItems.length) i = 0
+        }
+        return -1
+    }
+    let listCursor = hasList
+        ? (list.cursor != null ? list.cursor : firstSelectable(0, +1))
+        : -1
+    let listScroll = 0
+
+    // Layout
+    const buttonGap = 3
+    const maxFieldW = fields.reduce((m, f) => Math.max(m, f.width), 16)
+    const longestMsg = messageLines.reduce((m, l) => Math.max(m, l.length), 0)
+    // When the caller pins `list.width`, trust it — string `.length` overcounts
+    // visual width whenever items embed ANSI escapes or TVDOS \x84NNu sequences
+    // (e.g. taut's help popup, whose rows are pre-typeset with fg-colour escapes).
+    const longestItem = hasList && list.width == null
+        ? listItems.reduce((m, it) => Math.max(m, (it.label || '').length), 0)
+        : 0
+    const titleW    = title.length + 4
+    const btnRowW   = buttons.reduce((s, b) => s + b.label.length + 4, 0) + buttonGap * Math.max(0, buttons.length - 1)
+    const listMinW  = hasList
+        ? (list.width != null ? list.width + 4 : longestItem + 6)
+        : 0
+    const w = 2+Math.max(maxFieldW + 6, titleW + 4, longestMsg + 6, btnRowW + 4, listMinW, 22)
+
+    const msgRows      = messageLines.length + (messageLines.length > 0 ? 1 : 0)
+    const fieldsBlockH = fields.length * 4
+    const listBlockH   = hasList ? listHeight + 2 : 0   // top border + rows + bottom border
+
+    let bodyRows = msgRows
+    if (fields.length > 0) bodyRows += fieldsBlockH + 1   // +1 spacing after fields
+    if (hasList)           bodyRows += listBlockH + 1     // +1 spacing after list
+    if (bodyRows === 0)    bodyRows = 1                   // at least one row above buttons
+    const buttonsRowOff = 1 + bodyRows
+    const h = buttonsRowOff + 2
+
+    const screen = con.getmaxyx()
+    const row = Math.max(2, Math.floor((screen[0] - h) / 2))
+    const col = Math.max(2, Math.floor((screen[1] - w) / 2))
+
+    // Focus layout: 0..fields.length-1 = fields, [+1 = list if present], then buttons.
+    const listFocusIdx = hasList ? fields.length : -1
+    const buttonsFocusBase = fields.length + (hasList ? 1 : 0)
+    const totalFocus = buttonsFocusBase + buttons.length
+
+    // Pick initial focus: explicit default > list > first field > first button.
+    let focusIdx = -1
+    for (let i = 0; i < buttons.length; i++) {
+        if (buttons[i].default) { focusIdx = buttonsFocusBase + i; break }
+    }
+    if (focusIdx < 0) {
+        if (fields.length > 0)  focusIdx = 0
+        else if (hasList)       focusIdx = listFocusIdx
+        else                    focusIdx = buttonsFocusBase
+    }
+    let done = null
+
+    function fieldScroll(cur, fw) { return cur < fw ? 0 : cur - fw + 1 }
+    function fieldLabelRow(i) { return row + 1 + msgRows + i * 4 }
+    function fieldBoxRow(i)   { return fieldLabelRow(i) + 1 }
+    function fieldContentRow(i) { return fieldLabelRow(i) + 2 }
+    function fieldBoxCol() { return col + 2 }
+    function fieldContentRegion(i) { return { x: fieldBoxCol() + 1, y: fieldContentRow(i), w: fields[i].width } }
+
+    function listBlockTopRow() {
+        return row + 1 + msgRows + (fields.length > 0 ? fieldsBlockH + 1 : 0)
+    }
+    function listBlockCol()  { return col + 2 }
+    function listBlockWidth() { return w - 4 }      // inner content width incl. borders
+    function listContentRow(i) { return listBlockTopRow() + 1 + (i - listScroll) }
+    function listContentCol()  { return listBlockCol() + 1 }
+    function listScrollbarNeeded() {
+        if (!hasList) return false
+        if (list.showScrollbar != null) return list.showScrollbar
+        return listItems.length > listHeight
+    }
+    function listContentInnerW() {
+        return listBlockWidth() - 2 - (listScrollbarNeeded() ? 1 : 0)
+    }
+
+    function buttonRegions() {
+        let bx = col + Math.floor((w - btnRowW) / 2)
+        return buttons.map(b => {
+            const r = { x: bx, y: row + buttonsRowOff, w: b.label.length + 4 }
+            bx += b.label.length + 4 + buttonGap
+            return r
+        })
+    }
+
+    function drawFrameBox() {
+        con.color_pair(fg, bg)
+        for (let r = row; r < row + h; r++) {
+            con.move(r, col)
+            print(' '.repeat(w))
+        }
+        const wo = new WindowObject(col, row, w, h, ()=>{}, ()=>{}, title, opts.drawFrame)
+        wo.isHighlighted = true
+        wo.titleBack = bg
+        wo.drawFrame()
+        con.color_pair(fg, bg)
+    }
+
+    function drawMessage() {
+        if (messageLines.length === 0) return
+        con.color_pair(fg, bg)
+        for (let i = 0; i < messageLines.length; i++) {
+            con.move(row + 1 + i, col + 2)
+            print(messageLines[i].padEnd(w - 4, ' '))
+        }
+    }
+
+    function drawField(i) {
+        const f = fields[i]
+        const fbCol = fieldBoxCol()
+        const fbRow = fieldBoxRow(i)
+        const fw = f.width
+        const focused = (focusIdx === i)
+        const frameFg = focused ? fg : dimFg
+
+        // Label
+        con.color_pair(fg, bg)
+        con.move(fieldLabelRow(i), fbCol)
+        print(f.label)
+
+        // Top border (3px padding w/ TSVM chr rom)
+        con.color_pair(fieldBg, bg)
+        con.move(fbRow, fbCol)
+        print('\u00EC' + '\u00A9'.repeat(fw) + '\u00ED')
+
+        // Left border (3px padding w/ TSVM chr rom)
+        con.move(fbRow + 1, fbCol)
+        print('\u00AB')
+
+        // the content
+        con.color_pair(fg, fieldBg)
+        const s = fieldScroll(cursors[i], fw)
+        const vis = values[i].substring(s, s + fw)
+        print(vis.padEnd(fw, ' '))
+
+        // Right border (3px padding w/ TSVM chr rom)
+        con.color_pair(fieldBg, bg)
+        con.move(fbRow + 1, fbCol + fw + 1)
+        print('\u00AA')
+
+        // Bottom border (3px padding w/ TSVM chr rom)
+        con.move(fbRow + 2, fbCol)
+        print('\u00F4' + '\u00AC'.repeat(fw) + '\u00F5')
+        con.color_pair(fg, bg)
+    }
+
+    function drawList() {
+        if (!hasList) return
+        const lbCol = listBlockCol()
+        const lbRow = listBlockTopRow()
+        const lw    = listBlockWidth()
+        const innerW = listContentInnerW()
+        const focused = (focusIdx === listFocusIdx)
+        const frameFg = focused ? fg : dimFg
+        const sbar = listScrollbarNeeded()
+
+        // Top border (drawField style)
+        if (drawWell) {
+            con.color_pair(listBgColour, bg)
+            con.move(lbRow, lbCol)
+            print('\u00EC' + '\u00A9'.repeat(lw - 2) + '\u00ED')
+        }
+
+        // Side borders + rows
+        for (let r = 0; r < listHeight; r++) {
+            if (drawWell) {
+                con.color_pair(listBgColour, bg)
+                con.move(lbRow + 1 + r, lbCol)
+                print('\u00AB')
+                con.move(lbRow + 1 + r, lbCol + lw - 1)
+                print('\u00AA')
+            }
+
+            const idx = listScroll + r
+            con.move(lbRow + 1 + r, lbCol + 1)
+            if (idx >= listItems.length) {
+                con.color_pair(fg, listBgColour)
+                print(' '.repeat(innerW))
+                continue
+            }
+            const it = listItems[idx]
+            const isCursor = (idx === listCursor)
+            const ctx = {
+                y: lbRow + 1 + r,
+                x: lbCol + 1,
+                w: innerW,
+                item: it,
+                idx: idx,
+                isCursor: isCursor,
+                focused: focused,
+                listBg: listBgColour,
+                selBg: listSelBg,
+                fg: fg,
+                hlFg: hlFg,
+                dimFg: dimFg,
+            }
+            if (list.renderItem) {
+                list.renderItem(ctx)
+            } else {
+                const useFg = (isCursor && focused) ? hlFg : fg
+                const useBg = (isCursor && focused) ? listSelBg : listBgColour
+                con.color_pair(useFg, useBg)
+                const label = (it.label || '').substring(0, innerW - 1)
+                print(' ' + label.padEnd(innerW - 1, ' '))
+            }
+
+            // Scrollbar column
+            if (sbar) {
+                con.color_pair(dimFg, listBgColour)
+                con.move(lbRow + 1 + r, lbCol + lw - 2)
+                const maxScroll = Math.max(1, listItems.length - listHeight)
+                const indPos = (maxScroll <= 0) ? 0 : ((listScroll * (listHeight - 1) / maxScroll) | 0)
+                // seg: 0 = top cap, 1 = middle, 2 = bottom cap; +3 selects the
+                // filled (thumb) variant over the empty (trough) one.
+                const seg = (r === 0) ? 0 : (r === listHeight - 1) ? 2 : 1
+                con.addch(listScrollbarChars[(r === indPos) ? seg + 3 : seg])
+            }
+        }
+
+        // Bottom border
+        if (drawWell) {
+            con.color_pair(listBgColour, bg)
+            con.move(lbRow + 1 + listHeight, lbCol)
+            print('\u00F4' + '\u00AC'.repeat(lw - 2) + '\u00F5')
+            con.color_pair(fg, bg)
+        }
+    }
+
+    function drawButton(i, regions) {
+        const b = buttons[i]
+        const bIdx = buttonsFocusBase + i
+        const focused = (focusIdx === bIdx)
+        const r = regions[i]
+        const useFg = focused ? hlFg : fg
+        const useBg = focused ? focusBg : bg
+        con.color_pair(useFg, useBg)
+        con.move(r.y, r.x-1)
+        if (focused) {
+            con.color_pair(useBg, bg)
+            print('\u00DE')
+            con.color_pair(useFg, useBg)
+            print('[ ' + b.label + ' ]')
+            con.color_pair(useBg, bg)
+            print('\u00DD')
+        }
+        else
+            print(' [ ' + b.label + ' ] ')
+        con.color_pair(fg, bg)
+    }
+
+    function positionCaret() {
+        if (focusIdx < fields.length) {
+            const fw = fields[focusIdx].width
+            const s = fieldScroll(cursors[focusIdx], fw)
+            con.move(fieldContentRow(focusIdx), fieldBoxCol() + 1 + (cursors[focusIdx] - s))
+            con.curs_set(1)
+        } else {
+            con.curs_set(0)
+        }
+    }
+
+    function ensureListCursorVisible() {
+        if (!hasList) return
+        if (listCursor < 0) return
+        if (listCursor < listScroll) listScroll = listCursor
+        else if (listCursor >= listScroll + listHeight) listScroll = listCursor - listHeight + 1
+        const maxScroll = Math.max(0, listItems.length - listHeight)
+        if (listScroll > maxScroll) listScroll = maxScroll
+        if (listScroll < 0) listScroll = 0
+    }
+
+    function scrollListBy(dir) {
+        const maxScroll = Math.max(0, listItems.length - listHeight)
+        let s = listScroll + dir
+        if (s < 0) s = 0
+        if (s > maxScroll) s = maxScroll
+        listScroll = s
+    }
+
+    function moveListCursor(dir) {
+        if (!hasList || listItems.length === 0) return
+        // Scroll the view when nothing in the list is selectable (e.g. a help text body).
+        if (listCursor < 0) { scrollListBy(dir); return }
+        let next = listCursor
+        for (let n = 0; n < listItems.length; n++) {
+            next += dir
+            if (next < 0 || next >= listItems.length) return
+            if (listSelectable(listItems[next], next)) {
+                listCursor = next
+                ensureListCursorVisible()
+                return
+            }
+        }
+    }
+
+    function pageListCursor(dir) {
+        if (!hasList || listItems.length === 0) return
+        if (listCursor < 0) { scrollListBy(dir * listHeight); return }
+        let target = listCursor + dir * listHeight
+        if (target < 0) target = 0
+        if (target >= listItems.length) target = listItems.length - 1
+        // Snap to nearest selectable
+        let probe = target
+        const step = dir < 0 ? -1 : 1
+        while (probe >= 0 && probe < listItems.length && !listSelectable(listItems[probe], probe)) probe += step
+        if (probe < 0 || probe >= listItems.length) probe = firstSelectable(target, -step)
+        if (probe >= 0) { listCursor = probe; ensureListCursorVisible() }
+    }
+
+    function render() {
+        drawFrameBox()
+        drawMessage()
+        for (let i = 0; i < fields.length; i++) drawField(i)
+        drawList()
+        const regs = buttonRegions()
+        for (let i = 0; i < buttons.length; i++) drawButton(i, regs)
+        positionCaret()
+    }
+
+    function moveFocus(dir) {
+        focusIdx = (focusIdx + dir + totalFocus) % totalFocus
+        render()
+    }
+
+    function activateButton(i) {
+        done = {
+            action: buttons[i].action,
+            values: values.slice(),
+            listCursor: listCursor,
+            listItem: (hasList && listCursor >= 0) ? listItems[listCursor] : null,
+        }
+    }
+
+    function activateListItem(idx, key) {
+        if (!hasList || !listOnActivate) return false
+        if (idx < 0 || idx >= listItems.length) return false
+        if (!listSelectable(listItems[idx], idx)) return false
+        const result = listOnActivate(listItems[idx], idx, key)
+        if (result == null) {
+            // Callback consumed the event but kept the dialog open (e.g. radio
+            // toggle); reflect any state changes it made.
+            render()
+            return true
+        }
+        done = {
+            action: result,
+            values: values.slice(),
+            listCursor: idx,
+            listItem: listItems[idx],
+        }
+        return true
+    }
+
+    function hitTestMouse(ev) {
+        const cell = _pxToCell(ev[1], ev[2])
+        const cy = cell[0], cx = cell[1]
+        const btnRegs = buttonRegions()
+        for (let i = 0; i < btnRegs.length; i++) {
+            const r = btnRegs[i]
+            if (cy === r.y && cx >= r.x && cx < r.x + r.w) return { kind: 'button', idx: i }
+        }
+        for (let i = 0; i < fields.length; i++) {
+            const r = fieldContentRegion(i)
+            if (cy === r.y && cx >= r.x && cx < r.x + r.w) return { kind: 'field', idx: i, cx: cx, region: r }
+        }
+        if (hasList) {
+            const lbRow = listBlockTopRow()
+            const lbCol = listBlockCol()
+            const innerW = listContentInnerW()
+            if (cy > lbRow && cy <= lbRow + listHeight && cx >= lbCol + 1 && cx < lbCol + 1 + innerW) {
+                const r = cy - (lbRow + 1)
+                const idx = listScroll + r
+                if (idx >= 0 && idx < listItems.length) return { kind: 'list', idx: idx }
+            }
+            if (cy > lbRow && cy <= lbRow + listHeight && cx >= lbCol && cx < lbCol + listBlockWidth()) {
+                return { kind: 'listblank' }
+            }
+        }
+        return null
+    }
+
+    const externalCtx = {
+        render: () => render(),
+        close: (result) => {
+            done = Object.assign({
+                action: 'cancel',
+                values: values.slice(),
+                listCursor: listCursor,
+                listItem: (hasList && listCursor >= 0) ? listItems[listCursor] : null,
+            }, result || {})
+        },
+        getListCursor: () => listCursor,
+        setListCursor: (n) => {
+            if (!hasList) return
+            if (n < 0 || n >= listItems.length) return
+            listCursor = n
+            ensureListCursorVisible()
+        },
+    }
+
+    ensureListCursorVisible()
+    render()
+
+    let eventJustReceived = true
+    while (done === null) {
+        input.withEvent(ev => {
+            if (eventJustReceived && (ev[0] === 'key_down' || ev[0] === 'mouse_down')) {
+                eventJustReceived = false; return
+            }
+
+            if (ev[0] === 'mouse_move') {
+                const hit = hitTestMouse(ev)
+                if (hit && hit.kind === 'button') {
+                    const newFocus = buttonsFocusBase + hit.idx
+                    if (newFocus !== focusIdx) {
+                        focusIdx = newFocus
+                        render()
+                    }
+                }
+                return
+            }
+            if (ev[0] === 'mouse_down') {
+                if (ev[3] !== 1) return
+                const hit = hitTestMouse(ev)
+                if (!hit) return
+                if (hit.kind === 'button') {
+                    focusIdx = buttonsFocusBase + hit.idx
+                    render()
+                    activateButton(hit.idx)
+                    return
+                }
+                if (hit.kind === 'field') {
+                    focusIdx = hit.idx
+                    const fw = fields[hit.idx].width
+                    const s = fieldScroll(cursors[hit.idx], fw)
+                    const newCur = s + (hit.cx - hit.region.x)
+                    cursors[hit.idx] = Math.min(values[hit.idx].length, Math.max(0, newCur))
+                    render()
+                    return
+                }
+                if (hit.kind === 'list') {
+                    focusIdx = listFocusIdx
+                    if (listSelectable(listItems[hit.idx], hit.idx)) {
+                        listCursor = hit.idx
+                        ensureListCursorVisible()
+                        render()
+                        if (activateListItem(hit.idx, 'click')) return
+                    } else {
+                        render()
+                    }
+                    return
+                }
+                if (hit.kind === 'listblank') {
+                    focusIdx = listFocusIdx
+                    render()
+                    return
+                }
+                return
+            }
+            if (ev[0] === 'mouse_wheel' && hasList) {
+                const hit = hitTestMouse(ev)
+                if (!hit || (hit.kind !== 'list' && hit.kind !== 'listblank')) return
+                const dy = (ev[3] | 0) * 3
+                const maxScroll = Math.max(0, listItems.length - listHeight)
+                let next = listScroll + dy
+                if (next < 0) next = 0
+                if (next > maxScroll) next = maxScroll
+                if (next !== listScroll) { listScroll = next; render() }
+                return
+            }
+            if (ev[0] !== 'key_down') return
+            if (opts.disableKeyRepeat && 1 !== ev[2]) return
+            const ks = ev[1]
+            const shiftDown = (ev.includes(59) || ev.includes(60))
+
+            if (opts.onKey && opts.onKey(ks, shiftDown, externalCtx)) return
+
+            if (ks === '<ESC>') {
+                done = {
+                    action: 'cancel',
+                    values: values.slice(),
+                    listCursor: listCursor,
+                    listItem: (hasList && listCursor >= 0) ? listItems[listCursor] : null,
+                }
+                return
+            }
+
+            if (ks === '\t' || ks === '<TAB>') { moveFocus(shiftDown ? -1 : 1); return }
+
+            // Vertical movement: arrows operate within the list when it has focus.
+            if (ks === '<UP>') {
+                if (focusIdx === listFocusIdx) { moveListCursor(-1); render() }
+                else moveFocus(-1)
+                return
+            }
+            if (ks === '<DOWN>') {
+                if (focusIdx === listFocusIdx) { moveListCursor(+1); render() }
+                else moveFocus(+1)
+                return
+            }
+            if (ks === '<PAGE_UP>') {
+                if (focusIdx === listFocusIdx) { pageListCursor(-1); render() }
+                return
+            }
+            if (ks === '<PAGE_DOWN>') {
+                if (focusIdx === listFocusIdx) { pageListCursor(+1); render() }
+                return
+            }
+
+            if (ks === '<LEFT>') {
+                if (focusIdx < fields.length) {
+                    if (cursors[focusIdx] > 0) { cursors[focusIdx] -= 1; render() }
+                } else moveFocus(-1)
+                return
+            }
+            if (ks === '<RIGHT>') {
+                if (focusIdx < fields.length) {
+                    if (cursors[focusIdx] < values[focusIdx].length) { cursors[focusIdx] += 1; render() }
+                } else moveFocus(+1)
+                return
+            }
+            if (ks === '<HOME>') {
+                if (focusIdx < fields.length) { cursors[focusIdx] = 0; render() }
+                else if (focusIdx === listFocusIdx) {
+                    const t = firstSelectable(0, +1)
+                    if (t >= 0) { listCursor = t; ensureListCursorVisible(); render() }
+                    else        { listScroll = 0; render() }
+                }
+                return
+            }
+            if (ks === '<END>') {
+                if (focusIdx < fields.length) { cursors[focusIdx] = values[focusIdx].length; render() }
+                else if (focusIdx === listFocusIdx) {
+                    const t = firstSelectable(listItems.length - 1, -1)
+                    if (t >= 0) { listCursor = t; ensureListCursorVisible(); render() }
+                    else        { listScroll = Math.max(0, listItems.length - listHeight); render() }
+                }
+                return
+            }
+
+            if (focusIdx < fields.length) {
+                if (ks === '\n') {
+                    if (focusIdx < fields.length - 1) focusIdx = focusIdx + 1
+                    else if (hasList) focusIdx = listFocusIdx
+                    else focusIdx = buttonsFocusBase
+                    render()
+                    return
+                }
+                if (ks === '\x08') {
+                    const cur = cursors[focusIdx]
+                    if (cur > 0) {
+                        const v = values[focusIdx]
+                        values[focusIdx] = v.substring(0, cur - 1) + v.substring(cur)
+                        cursors[focusIdx] = cur - 1
+                        render()
+                    }
+                    return
+                }
+                if (ks === '<DEL>') {
+                    const cur = cursors[focusIdx]
+                    const v = values[focusIdx]
+                    if (cur < v.length) {
+                        values[focusIdx] = v.substring(0, cur) + v.substring(cur + 1)
+                        render()
+                    }
+                    return
+                }
+                if (typeof ks === 'string' && ks.length === 1) {
+                    const code = ks.charCodeAt(0)
+                    const cap = fields[focusIdx].maxLength != null
+                        ? fields[focusIdx].maxLength
+                        : fields[focusIdx].width * 4
+                    if (code >= 32 && code < 256 && values[focusIdx].length < cap) {
+                        const v = values[focusIdx]
+                        const cur = cursors[focusIdx]
+                        values[focusIdx] = v.substring(0, cur) + ks + v.substring(cur)
+                        cursors[focusIdx] = cur + 1
+                        render()
+                    }
+                    return
+                }
+            } else if (focusIdx === listFocusIdx) {
+                if (ks === '\n' || ks === ' ') {
+                    if (listCursor >= 0 && activateListItem(listCursor, ks)) return
+                }
+            } else {
+                if (ks === '\n' || ks === ' ') { activateButton(focusIdx - buttonsFocusBase); return }
+            }
+        })
+    }
+
+    // Modal-dialog convention: wait for the user to release whatever key closed
+    // the dialog before handing control back. TVDOS's input strobo
+    // (TVDOS.SYS:input.withEvent) keeps re-firing `key_down` for a held key
+    // once its ~250 ms initial-press delay elapses; without this drain a brief
+    // hold on Enter inside a popup would surface as a fresh Enter to whatever
+    // the popup was covering, e.g. activating the file under zfm's More menu.
+    // A mouse close (or any path with no key held) leaves the head key at 0
+    // and skips the wait.
+    sys.poke(-40, 255)
+    const heldHead = sys.peek(-41)
+    if (heldHead !== 0) {
+        while (true) {
+            input.withEvent(() => {})
+            if (sys.peek(-41) !== heldHead) break
+        }
+    }
+
+    con.curs_set(0)
+    con.color_pair(oldFG, oldBG)
+    return done
+}
+
+exports = { WindowObject, scrollVert, scrollHorz, showDialog }

assets/disk0/tvdos/sbin/vtmgr.js

@@ -0,0 +1,561 @@
+// vtmgr — virtual console manager for TVDOS
+//
+// Spawns up to 6 independent shell sessions (virtual consoles), each in its
+// own parallel GraalVM context with its own thread. Each pane runs a real
+// `command -fancy` shell. The dispatcher (this file) owns the physical
+// keyboard, polls Alt-N hotkeys at 30 Hz, blits the active pane's text
+// plane to the GPU's text area, and routes typed characters into the
+// active pane's input ring buffer.
+//
+// Hotkeys: Alt-1..Alt-6 switch to that VT (lazy-spawn on first use).
+//          Alt-0 cleanly tears down vtmgr.
+// Builtins: `chvt N` from inside a pane writes to the switch register.
+
+// ─── shared memory layout ───────────────────────────────────────────────────
+// CTRL_AREA (64 bytes from base)
+//   +0  active_vt        u8 (1..6)
+//   +1  switch_request   u8 (0 = none, 1..6 = target; set by chvt, cleared by dispatcher)
+//   +2  debounce_held    u8
+//   +3  vt_spawned_bits  u8 (bit n-1 set if VT n is alive)
+//   +4..63 reserved
+// VT block (× MAX_VT) starting at base + 64, each VT_BLOCK_SIZE bytes
+//   +0..7 reserved (cursor & color state lives inside text plane itself)
+//   +8    queue_head       u8 (next-read index)
+//   +9    queue_tail       u8 (next-write index)
+//   +10..11 reserved
+//   +12..267 queue_data    (256-byte ring buffer; one slot lost to full/empty disambiguation)
+//   +268..271 reserved (alignment)
+//   +272..7953 text_plane (7682 bytes; mirrors GPU textArea layout exactly)
+
+const MAX_VT = 6
+const CTRL_AREA_SIZE = 64
+const VT_BLOCK_SIZE = 8000
+const TEXT_PLANE_OFFSET = 272
+const TEXT_PLANE_SIZE = 7682
+const QUEUE_DATA_OFFSET = 12
+
+const CTRL_ACTIVE_VT      = 0
+const CTRL_SWITCH_REQUEST = 1
+const CTRL_DEBOUNCE_HELD  = 2
+const CTRL_SPAWNED_BITS   = 3
+
+const GPU_TEXTAREA_OFFSET = 253950
+const TEXT_COLS = 80
+const TEXT_ROWS = 32
+
+const TP_FORE_BASE = 2
+const TP_BACK_BASE = 2 + 2560
+const TP_TEXT_BASE = 2 + 2560 + 2560
+
+const TOTAL_ALLOC_SIZE = CTRL_AREA_SIZE + MAX_VT * VT_BLOCK_SIZE
+const BASE = sys.malloc(TOTAL_ALLOC_SIZE)
+if (!BASE || BASE === 0) { printerrln("vtmgr: sys.malloc failed"); return 1 }
+for (let i = 0; i < TOTAL_ALLOC_SIZE; i++) sys.poke(BASE + i, 0)
+
+const CTRL = BASE
+function vtBlockAddr(n)     { return BASE + CTRL_AREA_SIZE + (n - 1) * VT_BLOCK_SIZE }
+function vtTextPlaneAddr(n) { return vtBlockAddr(n) + TEXT_PLANE_OFFSET }
+
+// ─── pane bootstrap ─────────────────────────────────────────────────────────
+// Read TVDOS.SYS once at startup. Each pane's bootstrap embeds the source
+// (via JSON.stringify-escaped string literal) and evaluates it together with
+// the shell-start code as ONE direct-eval call. This matters because strict-
+// mode direct eval is scope-isolated; if TVDOS.SYS and the shell launcher
+// were two separate evals, the shell launcher wouldn't see `_TVDOS`,
+// `files`, `execApp`, etc. defined by the first eval.
+
+const TVDOS_SYS_SRC = files.open("A:/tvdos/TVDOS.SYS").sread()
+
+// _BIOS is set by the real BIOS before TVDOS.SYS runs; TVDOS.SYS reads
+// _BIOS.FIRST_BOOTABLE_PORT during init. Each pane is a fresh context with no
+// BIOS, so capture the live value here (vtmgr runs in the main context where
+// _BIOS is visible) and re-declare it in every pane bootstrap.
+const BIOS_FIRST_BOOTABLE_PORT = JSON.stringify(_BIOS.FIRST_BOOTABLE_PORT)
+
+// Environment no longer needs snapshotting/replaying: each pane re-evaluates
+// TVDOS.SYS, whose boot block runs \commandrc in every context, so the pane
+// gets the same PATH / KEYBOARD / etc. natively. The pane then runs
+// \AUTOEXEC.BAT (the per-console launch script: IME + interactive shell).
+
+function makePaneBootstrap(vtNum) {
+    const TP_BASE = vtTextPlaneAddr(vtNum)
+    const VT_BLK = vtBlockAddr(vtNum)
+
+    // Launcher code runs after TVDOS.SYS in the SAME eval scope, so `files`,
+    // `eval`, `_TVDOS` etc. resolve via lexical closure. TVDOS.SYS's boot
+    // block already ran \commandrc (env) and skipped its own AUTOEXEC because
+    // the pane sets _TVDOS_IS_VT_PANE; here we run \AUTOEXEC.BAT to launch the
+    // per-console shell.
+    const SHELL_START = ";\n"
+        + "var _cmdfileSrc = files.open('A:/tvdos/bin/command.js').sread();\n"
+        + "eval('var _VTSHELL=function(exec_args){' + _cmdfileSrc + '\\n};_VTSHELL')(['', '-c', '\\\\AUTOEXEC.BAT']);\n"
+
+    const combined = TVDOS_SYS_SRC + SHELL_START
+
+    const raw = `
+globalThis.VT_NUM = ${vtNum}
+globalThis.VT_TEXT_PLANE = ${TP_BASE}
+globalThis.VT_BLOCK_ADDR = ${VT_BLK}
+globalThis.VT_CTRL_ADDR = ${CTRL}
+const TP = ${TP_BASE}
+const VT_BLK = ${VT_BLK}
+const CTRL = ${CTRL}
+const QUEUE_DATA = VT_BLK + ${QUEUE_DATA_OFFSET}
+const QUEUE_HEAD_ADDR = VT_BLK + 8
+const QUEUE_TAIL_ADDR = VT_BLK + 9
+const ACTIVE_VT_ADDR = CTRL + ${CTRL_ACTIVE_VT}
+const COLS = ${TEXT_COLS}, ROWS = ${TEXT_ROWS}
+const FORE_BASE = ${TP_FORE_BASE}, BACK_BASE = ${TP_BACK_BASE}, TEXT_BASE = ${TP_TEXT_BASE}
+
+// ── output shims (write into the per-VT text-plane buffer in shared mem) ──
+// This is a faithful JS port of the GPU's TTY interpreter (GlassTty.acceptChar
+// + GraphicsAdapter handlers). TVDOS apps drive the screen by printing control
+// bytes and escape sequences through print(), so the shim must interpret them
+// exactly as the hardware would: the \\x84<decimal>u "emit char by code" escape
+// (used by con.prnch), CSI cursor moves / erase / SGR colours, and the ?25
+// cursor-visibility private sequence.
+let curX = 0, curY = 0
+let foreCol = 254
+let backCol = 255
+
+// Per-pane cursor visibility lives at VT_BLK+2 (1 = blink on, 0 = hidden).
+// The compositor pushes the active pane's value into the GPU's blink bit.
+const CURSOR_VIS_ADDR = VT_BLK + 2
+sys.poke(CURSOR_VIS_ADDR, 1)
+
+// SGR 30-37 / 40-47 → default 8-colour palette (matches GraphicsAdapter).
+const SGR_PAL = [240, 211, 61, 230, 49, 219, 114, 254]
+
+function writeCursor() {
+    let pos = curY * COLS + curX
+    sys.poke(TP + 0, pos & 0xFF)
+    sys.poke(TP + 1, (pos >> 8) & 0xFF)
+}
+function scrollBufUp(n) {
+    if (n < 1) n = 1
+    if (n > ROWS) n = ROWS
+    for (let p of [FORE_BASE, BACK_BASE, TEXT_BASE]) {
+        for (let y = 0; y < ROWS - n; y++) {
+            for (let x = 0; x < COLS; x++) {
+                sys.poke(TP + p + y * COLS + x, sys.peek(TP + p + (y + n) * COLS + x))
+            }
+        }
+        let clearVal = (p === TEXT_BASE) ? 0 : (p === FORE_BASE ? foreCol : backCol)
+        for (let y = ROWS - n; y < ROWS; y++)
+            for (let x = 0; x < COLS; x++) sys.poke(TP + p + y * COLS + x, clearVal)
+    }
+}
+function putCharRaw(x, y, c) {
+    if (x < 0 || x >= COLS || y < 0 || y >= ROWS) return
+    let off = y * COLS + x
+    sys.poke(TP + TEXT_BASE + off, c & 0xFF)
+    sys.poke(TP + FORE_BASE + off, foreCol)
+    sys.poke(TP + BACK_BASE + off, backCol)
+}
+// Mirror of GraphicsAdapter.setCursorPos: wrap on overflow x, scroll on
+// overflow y, clamp y above the screen.
+function setCursorPos(x, y) {
+    let nx = x, ny = y
+    if (nx >= COLS) { nx = 0; ny += 1 }
+    else if (nx < 0) nx = 0
+    if (ny < 0) ny = 0
+    else if (ny >= ROWS) { scrollBufUp(ny - ROWS + 1); ny = ROWS - 1 }
+    curX = nx; curY = ny
+    writeCursor()
+}
+
+// ── TTY actions (mirror the GraphicsAdapter overrides) ────────────────────
+function ttyPrintable(c) { putCharRaw(curX, curY, c); setCursorPos(curX + 1, curY) }
+function ttyCrlf() {
+    let ny = curY + 1
+    setCursorPos(0, (ny >= ROWS) ? ROWS - 1 : ny)
+    if (ny >= ROWS) scrollBufUp(1)
+}
+function ttyBackspace() { let x = curX, y = curY; setCursorPos(x - 1, y); putCharRaw(curX, curY, 0x20) }
+function ttyTab() { setCursorPos(((curX / 8 | 0) + 1) * 8, curY) }
+function ttyResetStatus() { foreCol = 253; backCol = 255 }
+function ttyEmitChar(code) { putCharRaw(curX, curY, code); setCursorPos(curX + 1, curY) }
+function ttyCursorUp(n) { setCursorPos(curX, curY - n) }
+function ttyCursorDown(n) { let ny = curY + n; setCursorPos(curX, (ny >= ROWS) ? ROWS - 1 : ny) }
+function ttyCursorFwd(n) { setCursorPos(curX + n, curY) }
+function ttyCursorBack(n) { setCursorPos(curX - n, curY) }
+function ttyCursorNextLine(n) { let ny = curY + n; setCursorPos(0, (ny >= ROWS) ? ROWS - 1 : ny); if (ny >= ROWS) scrollBufUp(ny - ROWS + 1) }
+function ttyCursorPrevLine(n) { setCursorPos(0, curY - n) }
+function ttyCursorX(n) { setCursorPos(n, curY) }
+function ttyCursorXY(row, col) { setCursorPos(col - 1, row - 1) }
+function ttyEraseInDisp(arg) {
+    if (arg === 2) {
+        for (let i = 0; i < COLS * ROWS; i++) {
+            sys.poke(TP + TEXT_BASE + i, 0)
+            sys.poke(TP + FORE_BASE + i, foreCol)
+            sys.poke(TP + BACK_BASE + i, backCol)
+        }
+        curX = 0; curY = 0; writeCursor()
+    }
+    // other args: GraphicsAdapter TODOs (throws); we no-op for safety
+}
+function ttySgr1(arg) {
+    if (arg >= 30 && arg <= 37) foreCol = SGR_PAL[arg - 30]
+    else if (arg >= 40 && arg <= 47) backCol = SGR_PAL[arg - 40]
+    else if (arg === 7) { let t = foreCol; foreCol = backCol; backCol = t }
+    else if (arg === 0) { foreCol = 253; backCol = 255; sys.poke(CURSOR_VIS_ADDR, 1) }
+}
+function ttySgr3(a1, a2, a3) {
+    if (a1 === 38 && a2 === 5) foreCol = a3
+    else if (a1 === 48 && a2 === 5) backCol = a3
+}
+function ttyPrivH(arg) { if (arg === 25) sys.poke(CURSOR_VIS_ADDR, 1) }
+function ttyPrivL(arg) { if (arg === 25) sys.poke(CURSOR_VIS_ADDR, 0) }
+
+// ── escape-sequence state machine (mirror of GlassTty.acceptChar) ─────────
+// States: 0 INITIAL, 1 ESC, 2 CSI, 3 NUM1, 4 SEP1, 5 NUM2, 6 SEP2, 7 NUM3,
+//         8 PRIVATESEQ, 9 PRIVATENUM, 10 XCSI, 11 XNUM1
+let escState = 0
+let escArgs = []
+function isDig(c) { return c >= 0x30 && c <= 0x39 }
+function escReset() { escState = 0; escArgs.length = 0 }
+// reject() in hardware returns the char as printable; replicate by printing it
+function escRejectPrint(c) { escReset(); ttyPrintable(c) }
+
+function processByte(c) {
+    switch (escState) {
+        case 0: // INITIAL
+            if (c === 0x1B) escState = 1
+            else if (c === 0x84) escState = 10
+            else if (c === 0x0A) ttyCrlf()
+            else if (c === 0x08) ttyBackspace()
+            else if (c === 0x09) ttyTab()
+            else if (c === 0x07) { /* bell */ }
+            else if (c >= 0x00 && c <= 0x1F) { /* other control: ignored */ }
+            else ttyPrintable(c)
+            break
+        case 1: // ESC
+            if (c === 0x63) { ttyResetStatus(); escReset() }       // 'c'
+            else if (c === 0x5B) escState = 2                       // '['
+            else escRejectPrint(c)
+            break
+        case 2: // CSI
+            if (c === 0x41) { ttyCursorUp(1); escReset() }
+            else if (c === 0x42) { ttyCursorDown(1); escReset() }
+            else if (c === 0x43) { ttyCursorFwd(1); escReset() }
+            else if (c === 0x44) { ttyCursorBack(1); escReset() }
+            else if (c === 0x45) { ttyCursorNextLine(1); escReset() }
+            else if (c === 0x46) { ttyCursorPrevLine(1); escReset() }
+            else if (c === 0x47) { ttyCursorX(1); escReset() }
+            else if (c === 0x4A) { ttyEraseInDisp(0); escReset() }
+            else if (c === 0x4B) { escReset() }                    // eraseInLine: no-op
+            else if (c === 0x53) { scrollBufUp(1); escReset() }    // S
+            else if (c === 0x54) { escReset() }                    // T scrollDown: no-op
+            else if (c === 0x6D) { ttySgr1(0); escReset() }        // m
+            else if (c === 0x3F) escState = 8                      // '?'
+            else if (c === 0x3B) { escArgs.push(0); escState = 4 } // ';'
+            else if (isDig(c)) { escArgs.push(c - 0x30); escState = 3 }
+            else escRejectPrint(c)
+            break
+        case 3: // NUM1
+            if (c === 0x41) { ttyCursorUp(escArgs.pop()); escReset() }
+            else if (c === 0x42) { ttyCursorDown(escArgs.pop()); escReset() }
+            else if (c === 0x43) { ttyCursorFwd(escArgs.pop()); escReset() }
+            else if (c === 0x44) { ttyCursorBack(escArgs.pop()); escReset() }
+            else if (c === 0x45) { ttyCursorNextLine(escArgs.pop()); escReset() }
+            else if (c === 0x46) { ttyCursorPrevLine(escArgs.pop()); escReset() }
+            else if (c === 0x47) { ttyCursorX(escArgs.pop()); escReset() }
+            else if (c === 0x4A) { ttyEraseInDisp(escArgs.pop()); escReset() }
+            else if (c === 0x4B) { escArgs.pop(); escReset() }
+            else if (c === 0x53) { scrollBufUp(escArgs.pop()); escReset() }
+            else if (c === 0x54) { escArgs.pop(); escReset() }
+            else if (c === 0x6D) { ttySgr1(escArgs.pop()); escReset() }
+            else if (c === 0x3B) escState = 4
+            else if (isDig(c)) escArgs.push(escArgs.pop() * 10 + (c - 0x30))
+            else escRejectPrint(c)
+            break
+        case 4: // SEP1 (seen "n;")
+            if (isDig(c)) { escArgs.push(c - 0x30); escState = 5 }
+            else if (c === 0x48) { let a1 = escArgs.pop(); ttyCursorXY(a1, 0); escReset() }   // H
+            else if (c === 0x6D) { ttySgr1(escArgs.pop()); escReset() }                       // m (2-arg unimpl in HW)
+            else if (c === 0x3B) { escArgs.push(0); escState = 6 }
+            else escRejectPrint(c)
+            break
+        case 5: // NUM2 (seen "n;n")
+            if (isDig(c)) escArgs.push(escArgs.pop() * 10 + (c - 0x30))
+            else if (c === 0x48) { let a2 = escArgs.pop(), a1 = escArgs.pop(); ttyCursorXY(a1, a2); escReset() }
+            else if (c === 0x6D) { escArgs.pop(); escArgs.pop(); escReset() }  // 2-arg SGR unimpl in HW
+            else if (c === 0x3B) escState = 6
+            else escRejectPrint(c)
+            break
+        case 6: // SEP2 (seen "n;n;")
+            if (c === 0x6D) { let a2 = escArgs.pop(), a1 = escArgs.pop(); ttySgr3(a1, a2, 0); escReset() }
+            else if (isDig(c)) { escArgs.push(c - 0x30); escState = 7 }
+            else escRejectPrint(c)
+            break
+        case 7: // NUM3 (seen "n;n;n")
+            if (isDig(c)) escArgs.push(escArgs.pop() * 10 + (c - 0x30))
+            else if (c === 0x6D) { let a3 = escArgs.pop(), a2 = escArgs.pop(), a1 = escArgs.pop(); ttySgr3(a1, a2, a3); escReset() }
+            else escRejectPrint(c)
+            break
+        case 8: // PRIVATESEQ (seen "?")
+            if (isDig(c)) { escArgs.push(c - 0x30); escState = 9 }
+            else escRejectPrint(c)
+            break
+        case 9: // PRIVATENUM (seen "?n")
+            if (c === 0x68) { ttyPrivH(escArgs.pop()); escReset() }       // h
+            else if (c === 0x6C) { ttyPrivL(escArgs.pop()); escReset() }  // l
+            else if (isDig(c)) escArgs.push(escArgs.pop() * 10 + (c - 0x30))
+            else escRejectPrint(c)
+            break
+        case 10: // XCSI (seen \\x84)
+            if (c === 0x75) { ttyEmitChar(0); escReset() }                // 'u'
+            else if (isDig(c)) { escArgs.push(c - 0x30); escState = 11 }
+            else escRejectPrint(c)
+            break
+        case 11: // XNUM1 (seen \\x84<digits>)
+            if (c === 0x75) { ttyEmitChar(escArgs.pop()); escReset() }     // 'u'
+            else if (isDig(c)) escArgs.push(escArgs.pop() * 10 + (c - 0x30))
+            else escRejectPrint(c)
+            break
+    }
+}
+
+print = function(s) {
+    if (s === undefined || s === null) return
+    let str = '' + s
+    for (let i = 0; i < str.length; i++) processByte(str.charCodeAt(i))
+}
+println = function(s) {
+    if (s === undefined) print("\\n")
+    else print(s + "\\n")
+}
+printerr = function(s) { print(s) }
+printerrln = function(s) { println(s) }
+
+// command.js's shell.execute reassigns the global print/println/printerr/
+// printerrln to shell.stdio.out.* (which call sys.print → physical GPU,
+// bypassing these shims). Expose the buffer writers through a global hook so
+// shell.stdio.out can delegate to them when running inside a VT pane. The
+// non-VT path in command.js stays unchanged (hook is undefined there).
+globalThis.__VT_OUT = { print: print, println: println, printerr: printerr, printerrln: printerrln }
+
+// con.move / con.getyx are 1-based in TVDOS (graphics.setCursorYX does cx-1,
+// getCursorYX returns cx+1). Internal curX/curY are 0-based, so convert.
+con.move = function(y, x) {
+    curY = Math.max(0, Math.min(ROWS - 1, (y | 0) - 1))
+    curX = Math.max(0, Math.min(COLS - 1, (x | 0) - 1))
+    writeCursor()
+}
+con.getyx = function() { return [curY + 1, curX + 1] }
+con.getmaxyx = function() { return [ROWS, COLS] }
+con.color_pair = function(f, b) { foreCol = f & 0xFF; backCol = b & 0xFF }
+con.color_fore = function(n) { foreCol = n & 0xFF }
+con.color_back = function(n) { backCol = n & 0xFF }
+con.get_color_fore = function() { return foreCol }
+con.get_color_back = function() { return backCol }
+// addch writes a glyph at the cursor WITHOUT advancing — matching
+// graphics.putSymbol(). TVDOS code pairs addch with explicit curs_right();
+// advancing here would double-step and leave gaps (e.g. the fancy prompt).
+con.addch = function(c) { putCharRaw(curX, curY, c) }
+con.mvaddch = function(y, x, c) { con.move(y, x); con.addch(c) }
+con.curs_up = function(n) { n = n || 1; curY = Math.max(0, curY - n); writeCursor() }
+con.curs_down = function(n) { n = n || 1; curY = Math.min(ROWS - 1, curY + n); writeCursor() }
+con.curs_left = function(n) { n = n || 1; curX = Math.max(0, curX - n); writeCursor() }
+con.curs_right = function(n) { n = n || 1; curX = Math.min(COLS - 1, curX + n); writeCursor() }
+con.curs_set = function(arg) { sys.poke(CURSOR_VIS_ADDR, ((arg | 0) === 0) ? 0 : 1) }
+con.video_reverse = function() { /* unsupported; ANSI swallowed */ }
+con.reset_graphics = function() { foreCol = 254; backCol = 255 }
+con.clear = function() {
+    for (let i = 0; i < COLS * ROWS; i++) {
+        sys.poke(TP + TEXT_BASE + i, 0)
+        sys.poke(TP + FORE_BASE + i, foreCol)
+        sys.poke(TP + BACK_BASE + i, backCol)
+    }
+    curX = 0; curY = 0; writeCursor()
+}
+// prnch prints a glyph and DOES advance (unlike addch) — the real impl emits
+// it through print() as \\x84<code>u, so route it through the interpreter.
+con.prnch = function(c) {
+    if (Array.isArray(c)) c.forEach(x => ttyEmitChar(x))
+    else ttyEmitChar(c)
+}
+
+// ── input shims ──────────────────────────────────────────────────────────
+// Pane reads from its own ring buffer in shared mem. NEVER touches physical
+// keyboard MMIO — that's the dispatcher's exclusive territory. Cooperative
+// gate on active_vt keeps background panes parked when they call getch.
+
+function queuePop() {
+    let head = sys.peek(QUEUE_HEAD_ADDR)
+    let tail = sys.peek(QUEUE_TAIL_ADDR)
+    if (head === tail) return -1
+    let b = sys.peek(QUEUE_DATA + head)
+    sys.poke(QUEUE_HEAD_ADDR, (head + 1) & 0xFF)
+    return b
+}
+con.getch = function() {
+    while (true) {
+        if (sys.peek(ACTIVE_VT_ADDR) === VT_NUM) {
+            let k = queuePop()
+            if (k >= 0) return k
+        }
+        sys.sleep(20)
+    }
+}
+con.hitterminate = function() { return false }
+con.hiteof = function() { return false }
+con.resetkeybuf = function() { sys.poke(QUEUE_HEAD_ADDR, sys.peek(QUEUE_TAIL_ADDR)) }
+con.poll_keys = function() { return [0,0,0,0,0,0,0,0] }
+
+// ── TVDOS.SYS init flags + BIOS stub ───────────────────────────────────────
+globalThis._TVDOS_IS_VT_PANE = true
+globalThis._BIOS = { FIRST_BOOTABLE_PORT: ${BIOS_FIRST_BOOTABLE_PORT} }
+
+// ── load TVDOS.SYS and run AUTOEXEC.BAT (the per-console shell) in one direct-eval ─────
+// Strict-mode direct eval is scope-isolated, so TVDOS.SYS's \`const _TVDOS\`
+// only survives within the eval scope. The shell launcher must run inside
+// the same eval to access it (via lexical closure into nested evals).
+eval(${JSON.stringify(combined)})
+`
+    // The outer execApp's injectIntChk rewrote the first while/for/do (each
+    // kind) in our literal source to call a per-exec SIGTERM check function.
+    // Some of those rewrites landed inside this template literal — the pane
+    // has no such symbol in scope. Strip them; panes don't need SIGTERM
+    // checks (parallel.kill handles teardown).
+    return raw.replace(/tvdosSIGTERM_[A-Za-z0-9_]+\(\);?/g, '')
+}
+
+// ─── pane lifecycle ─────────────────────────────────────────────────────────
+// Lazy spawn: VT 1 at boot; VT 2-6 the first time the user requests them.
+// Re-spawn if the previous pane's thread has died (e.g. user typed `exit`).
+
+const panes = {}  // n -> { runner, thread }
+
+function isPaneAlive(n) {
+    return panes[n] && parallel.isRunning(panes[n].thread)
+}
+
+function spawnPane(n) {
+    serial.println("[vtmgr] spawning VT " + n)
+    let runner = parallel.spawnNewContext()
+    let thread = parallel.attachProgram("vt" + n, runner, makePaneBootstrap(n))
+    parallel.launch(thread)
+    panes[n] = { runner: runner, thread: thread }
+    sys.poke(CTRL + CTRL_SPAWNED_BITS, sys.peek(CTRL + CTRL_SPAWNED_BITS) | (1 << (n - 1)))
+}
+
+function ensurePane(n) {
+    if (!isPaneAlive(n)) {
+        sys.poke(CTRL + CTRL_SPAWNED_BITS, sys.peek(CTRL + CTRL_SPAWNED_BITS) & ~(1 << (n - 1)))
+        spawnPane(n)
+    }
+}
+
+ensurePane(1)
+sys.poke(CTRL + CTRL_ACTIVE_VT, 1)
+// VT 1's TVDOS.SYS eval is slow; give it room before we start compositing.
+sys.sleep(800)
+
+// ─── compositor / dispatcher loop ───────────────────────────────────────────
+// 30 Hz: blit active pane → GPU text area; honour switch_request; detect
+// Alt-N with debounce; drain typed chars into active pane's queue.
+
+const gpuBase = graphics.getGpuMemBase()
+const TEXTAREA_BASE_ABS = gpuBase - GPU_TEXTAREA_OFFSET
+function blitVt(srcAddr) {
+    sys.memcpy(srcAddr, TEXTAREA_BASE_ABS, TEXT_PLANE_SIZE - 2)
+    sys.poke(TEXTAREA_BASE_ABS - (TEXT_PLANE_SIZE - 2), sys.peek(srcAddr + TEXT_PLANE_SIZE - 2))
+    sys.poke(TEXTAREA_BASE_ABS - (TEXT_PLANE_SIZE - 1), sys.peek(srcAddr + TEXT_PLANE_SIZE - 1))
+}
+
+// GPU textmode-attribute MMIO byte (offset 6): bit 0 = blinkCursor, bit 1 =
+// rawMode, bits 4-7 = chrrom. We flip only bit 0 to match the active pane's
+// cursor visibility. getGpuMemBase() = -1 - 1MB*slot; the peripheral's MMIO
+// window sits at IOSpace offset 128KB*slot, so MMIO byte k = -1 - (128KB*slot + k).
+const gpuSlot = (((-gpuBase) - 1) / 1048576) | 0
+const GPU_MMIO_ATTR = -1 - (131072 * gpuSlot + 6)
+let lastCursorVis = -1
+function applyCursorVis(active) {
+    let vis = sys.peek(vtBlockAddr(active) + 2)
+    if (vis === lastCursorVis) return
+    let attr = sys.peek(GPU_MMIO_ATTR)
+    sys.poke(GPU_MMIO_ATTR, vis ? (attr | 1) : (attr & 0xFE))
+    lastCursorVis = vis
+}
+
+function queuePush(vtN, byte) {
+    let qBase = vtBlockAddr(vtN)
+    let head = sys.peek(qBase + 8)
+    let tail = sys.peek(qBase + 9)
+    let next = (tail + 1) & 0xFF
+    if (next === head) return false
+    sys.poke(qBase + QUEUE_DATA_OFFSET + tail, byte)
+    sys.poke(qBase + 9, next)
+    return true
+}
+
+function switchTo(n) {
+    if (n < 1 || n > MAX_VT) return
+    ensurePane(n)
+    sys.poke(CTRL + CTRL_ACTIVE_VT, n)
+}
+
+sys.poke(-39, 1)  // enable physical keyboard input collection
+
+let running = true
+while (running) {
+    let active = sys.peek(CTRL + CTRL_ACTIVE_VT)
+    if (active < 1 || active > MAX_VT) active = 1
+    blitVt(vtTextPlaneAddr(active))
+    applyCursorVis(active)
+
+    // honour chvt's switch request
+    let req = sys.peek(CTRL + CTRL_SWITCH_REQUEST)
+    if (req >= 1 && req <= MAX_VT) {
+        if (req !== active) {
+            serial.println("[vtmgr] chvt switch -> VT " + req)
+            switchTo(req)
+        }
+        sys.poke(CTRL + CTRL_SWITCH_REQUEST, 0)
+    }
+
+    // Alt-N (and Alt-0 = exit) detection
+    sys.poke(-40, 1)
+    let keys = [sys.peek(-41), sys.peek(-42), sys.peek(-43), sys.peek(-44),
+                sys.peek(-45), sys.peek(-46), sys.peek(-47), sys.peek(-48)]
+    let altHeld = keys.indexOf(57) >= 0 || keys.indexOf(58) >= 0
+    let digit = -1
+    for (let n = 0; n <= MAX_VT; n++) {
+        if (keys.indexOf(7 + n) >= 0) { digit = n; break }
+    }
+    let debounce = sys.peek(CTRL + CTRL_DEBOUNCE_HELD) !== 0
+
+    if (debounce) {
+        if (!altHeld && digit < 0) sys.poke(CTRL + CTRL_DEBOUNCE_HELD, 0)
+    }
+    else if (altHeld && digit === 0) {
+        serial.println("[vtmgr] Alt-0 -> exit")
+        running = false
+        sys.poke(CTRL + CTRL_DEBOUNCE_HELD, 1)
+        sys.poke(-39, 1)
+    }
+    else if (altHeld && digit >= 1) {
+        serial.println("[vtmgr] Alt-" + digit + " -> switching to VT " + digit)
+        switchTo(digit)
+        sys.poke(CTRL + CTRL_DEBOUNCE_HELD, 1)
+        sys.poke(-39, 1)  // swallow the digit char so it doesn't leak into the queue
+    }
+
+    if (!running) break
+
+    // drain typed chars into the active pane's queue
+    while (sys.peek(-50) !== 0) {
+        let k = sys.peek(-38)
+        if (k < 0) k += 256
+        queuePush(active, k)
+    }
+
+    sys.sleep(33)
+}
+
+for (let n = 1; n <= MAX_VT; n++) if (panes[n]) parallel.kill(panes[n].thread)
+con.color_pair(254, 255)
+con.clear()
+println("vtmgr exited.")
+return 0

it2taud.py

@@ -35,6 +35,7 @@ Effect support:
 """
 
 import argparse
+import copy
 import struct
 import sys
 
@@ -55,7 +56,8 @@ from taud_common import (
     encode_cue, deduplicate_patterns,
     normalise_sample, encode_song_entry, nearest_minifloat, compress_blob,
     CUE_INST_NOP, CUE_INST_HALT, CUE_INST_LEN, cue_instruction_len,
-    build_project_data,
+    build_project_data, detect_subsongs,
+    IXMP_PAN_NO_OVERRIDE,
 )
 
 
@@ -293,11 +295,11 @@ def _it214_decompress_block(payload: bytes, num_samples: int,
 
     return out
 
-def it214_decompress(blob: bytes, smp_offset: int, num_samples: int,
-                     is_16bit: bool, is_it215: bool) -> bytes:
-    """Decode IT2.14/IT2.15 compressed sample data. Returns raw PCM bytes (signed)."""
+def _it214_decompress_channel(blob: bytes, pos: int, num_samples: int,
+                              is_16bit: bool, is_it215: bool) -> tuple:
+    """Decode one channel of IT2.14/IT2.15 compressed data. Returns
+    (raw PCM bytes, next position after consumed blocks)."""
     block_size = 0x4000 if is_16bit else 0x8000
-    pos = smp_offset
     out_samples = []
 
     while len(out_samples) < num_samples:
@@ -317,9 +319,24 @@ def it214_decompress(blob: bytes, smp_offset: int, num_samples: int,
         result = bytearray(len(out_samples) * 2)
         for i, s in enumerate(out_samples):
             struct.pack_into('<h', result, i * 2, max(-32768, min(32767, s)))
-        return bytes(result)
+        return bytes(result), pos
     else:
-        return bytes(s & 0xFF for s in out_samples)
+        return bytes(s & 0xFF for s in out_samples), pos
+
+
+def it214_decompress(blob: bytes, smp_offset: int, num_samples: int,
+                     is_16bit: bool, is_it215: bool,
+                     is_stereo: bool = False) -> bytes:
+    """Decode IT2.14/IT2.15 compressed sample data. Returns raw PCM bytes
+    (signed). For stereo samples, returns the left channel block followed
+    by the right channel block (matching IT's on-disk SF_SS layout)."""
+    left, pos = _it214_decompress_channel(blob, smp_offset, num_samples,
+                                           is_16bit, is_it215)
+    if not is_stereo:
+        return left
+    right, _ = _it214_decompress_channel(blob, pos, num_samples,
+                                          is_16bit, is_it215)
+    return left + right
 
 
 # ── IT sample parser ──────────────────────────────────────────────────────────
@@ -383,7 +400,7 @@ def parse_samples(data: bytes, h: ITHeader, decompress: bool) -> list:
                     try:
                         is_it215 = bool(s.cvt & 0x04)
                         raw = it214_decompress(data, s.smp_point, s.length,
-                                               s.is_16bit, is_it215)
+                                               s.is_16bit, is_it215, s.is_stereo)
                         s.sample_data = normalise_sample(raw, True,
                                                           s.is_16bit, s.is_stereo, s.name)
                         s.length = len(s.sample_data)
@@ -419,7 +436,10 @@ class ITInstrument:
                  'vol_env_loop', 'pan_env_loop', 'pf_env_loop',
                  'vol_env_sus', 'pan_env_sus', 'pf_env_sus',
                  'ifc', 'ifr', 'fadeout', 'pps', 'ppc', 'rv', 'rp', 'nna',
-                 'dct', 'dca')
+                 'dct', 'dca', 'keyboard')
+    # keyboard: list[int], 120 entries — keyboard[it_note] = sample_1based (0 = none).
+    # Carried verbatim from the IT file so the Ixmp emitter can build patches that
+    # cover non-canonical-sample note ranges. terranmon.txt "Ixmp" + Schism iti.c:80.
     # vol_envelope / pan_envelope / pf_envelope: list of 25 (value, minifloat_idx) tuples, or None
     # *_env_sustain: int (16-bit, 0b 0ut sssss pcb eeeee), 0 = no envelope
     # pf_is_filter: bool — pf envelope mode (False = pitch, True = filter)
@@ -462,6 +482,7 @@ def parse_instruments(data: bytes, h: ITHeader) -> list:
             kb_note = data[ptr + 0x44 + n*2]
             kb_smp  = data[ptr + 0x44 + n*2 + 1]
             keyboard.append(kb_smp)  # 0 = no sample
+        inst.keyboard = keyboard
 
         # Pick C-5 (note 60) sample; fall back to most-frequent non-zero
         c5_smp = keyboard[60] if 60 < len(keyboard) else 0
@@ -697,7 +718,7 @@ def encode_note_it(it_note: int) -> int:
         # IT C-5 anchors to Taud C-4, so offset = it_note - 60.
         semis = it_note - 60
         val = round(TAUD_C4 + semis * 4096 / 12)
-        return max(1, min(0xFFFD, val))
+        return max(0x20, min(0xFFFF, val))
     return NOTE_NOP
 
 
@@ -1057,7 +1078,10 @@ def split_patterns(patterns_rows: list):
 
 def _remap_bc_effects(chunks: list, chunk_map: list,
                       order_list: list, it_ord_to_taud_cue: dict,
-                      num_channels: int) -> None:
+                      num_channels: int,
+                      *, default_target: int = None,
+                      warn_label: str = '',
+                      chunk_indices=None) -> None:
     """Rewrite B (position-jump) effects using remapped order indices.
 
     B effects are rewritten to point to the first chunk of the target IT
@@ -1068,15 +1092,163 @@ def _remap_bc_effects(chunks: list, chunk_map: list,
     being emitted by the engine when the source pattern's row pointer
     naturally hits a chunk boundary. Since splits at exact multiples of
     64 have no LEN gap, no C-skip injection is required.
+
+    `default_target` (multi-song): when a Bxx points to an order outside
+    `it_ord_to_taud_cue` (a cross-subsong jump), rewrite to this cue
+    index instead of preserving the literal target. Set to 0 to make
+    cross-song jumps loop the subsong; leave None for legacy behaviour.
+
+    `chunk_indices`: optional iterable; when provided, only these chunks
+    are visited. Used by multi-song to skip unreferenced chunks (avoids
+    spurious cross-song warnings on chunks that won't be emitted).
     """
-    for ci, chunk_grid in enumerate(chunks):
+    crossings = 0
+    iter_indices = (chunk_indices if chunk_indices is not None
+                    else range(len(chunks)))
+    for ci in iter_indices:
+        chunk_grid = chunks[ci]
         for ch in range(num_channels):
             if ch >= len(chunk_grid): continue
             for row in chunk_grid[ch]:
                 if row.effect == EFF_B:
                     it_tgt = row.effect_arg
-                    taud_cue = it_ord_to_taud_cue.get(it_tgt, it_tgt)
-                    row.effect_arg = taud_cue & 0xFF
+                    if it_tgt in it_ord_to_taud_cue:
+                        row.effect_arg = it_ord_to_taud_cue[it_tgt] & 0xFF
+                    elif default_target is not None:
+                        crossings += 1
+                        row.effect_arg = default_target & 0xFF
+                    else:
+                        row.effect_arg = it_tgt & 0xFF
+    if crossings and warn_label:
+        vprint(f"  warning: {warn_label}: {crossings} Bxx target(s) cross "
+               f"subsong boundary; clamped to cue {default_target}")
+
+
+# ── Ixmp patch builder (multi-sample IT instruments) ─────────────────────────
+
+def _it_note_to_taud(note: int, clamp_low: bool = False, clamp_high: bool = False) -> int:
+    """IT note (0..119, C-5 = 60) → Taud 4096-TET noteVal anchored at TAUD_C4.
+    `clamp_low`/`clamp_high` expand the bottom/top of the keyboard to cover the
+    full Taud playable range, so patches at the keyboard's edges don't leave
+    notes outside the trigger rectangle unmatched."""
+    if clamp_low:  return 0x0000
+    if clamp_high: return 0xFFFF
+    val = round(TAUD_C4 + (note - 60) * 4096 / 12)
+    return max(0x0020, min(0xFFFF, val))
+
+
+def _build_it_ixmp_patches(inst, samples, extras_offsets) -> list:
+    """For one IT instrument, return a list of Ixmp patch dicts covering every
+    keyboard cell that maps to a NON-canonical sample. The canonical sample is
+    served by the base instrument record so no patch is emitted for it (the
+    engine falls through to the base inst when no patch matches).
+
+    Note ranges are contiguous runs of keyboard cells that point at the same
+    sample. Per the Ixmp spec each (pitch_start..pitch_end, volume_start..end)
+    rectangle MUST NOT overlap any other patch on the same instrument; this is
+    guaranteed here because the keyboard mapping itself is a partition."""
+    canonical = inst.canonical_sample
+    kbd = getattr(inst, 'keyboard', None)
+    if not kbd:
+        return []
+    # Distinct non-canonical samples referenced.
+    distinct = []
+    seen = set()
+    for kb_smp in kbd:
+        if kb_smp == 0 or kb_smp == canonical:
+            continue
+        if kb_smp not in seen and 1 <= kb_smp <= len(samples) and samples[kb_smp - 1] is not None:
+            seen.add(kb_smp); distinct.append(kb_smp)
+    if not distinct:
+        return []
+
+    patches = []
+    for smp_1based in distinct:
+        si = smp_1based - 1
+        s = samples[si]
+        if not s.sample_data:
+            continue
+        sample_ptr = extras_offsets.get(('it_smp', si))
+        if sample_ptr is None:
+            continue   # not in the pool — bin overflow or corrupt source
+
+        # Per-sample loop / sustain encoding (mirrors build_sample_inst_bin_it).
+        if s.flags & IT_SMP_SUS_LOOP:
+            ls = min(s.sus_beg, 65535); le = min(s.sus_end, 65535)
+            sustain_bit = 0x4
+            pingpong = bool(s.flags & IT_SMP_PINGPONG_SUS)
+            has_loop = True
+        elif s.has_loop:
+            ls = min(s.loop_beg, 65535); le = min(s.loop_end, 65535)
+            sustain_bit = 0x0
+            pingpong = bool(s.flags & IT_SMP_PINGPONG)
+            has_loop = True
+        else:
+            ls = 0; le = 0
+            sustain_bit = 0x0
+            pingpong = False
+            has_loop = False
+        loop_mode = (2 if (has_loop and pingpong) else (1 if has_loop else 0)) | sustain_bit
+
+        # Per-sample default volume / pan / auto-vibrato — mirrors the
+        # use_instruments inst-record path so behaviour is identical when the
+        # patch sample matches what the base instrument would have stored.
+        smp_vol  = min(getattr(s, 'vol', 64), 64)
+        dnv      = min(255, round(smp_vol * 255 / 64))
+        smp_dfp  = getattr(s, 'dfp', 0)
+        default_pan = (min(255, max(0, round((smp_dfp & 0x7F) * 255 / 64)))
+                       if (smp_dfp & 0x80) else IXMP_PAN_NO_OVERRIDE)
+        vib_speed_taud = min(255, round(getattr(s, 'av_speed', 0) * 255 / 64))
+        vib_depth_taud = min(255, round(getattr(s, 'av_depth', 0) * 255 / 64))
+        vib_rate_taud  = getattr(s, 'av_sweep', 0) & 0xFF
+        vib_wave_taud  = getattr(s, 'av_wave',  0) & 0x07
+
+        # Find contiguous IT-note ranges where the keyboard points at this sample.
+        run_start = None
+        for n in range(120):
+            if kbd[n] == smp_1based:
+                if run_start is None:
+                    run_start = n
+            else:
+                if run_start is not None:
+                    _emit_patch(patches, run_start, n - 1, sample_ptr, s,
+                                ls, le, loop_mode, default_pan, dnv,
+                                vib_speed_taud, vib_depth_taud, vib_rate_taud, vib_wave_taud)
+                    run_start = None
+        if run_start is not None:
+            _emit_patch(patches, run_start, 119, sample_ptr, s,
+                        ls, le, loop_mode, default_pan, dnv,
+                        vib_speed_taud, vib_depth_taud, vib_rate_taud, vib_wave_taud)
+    return patches
+
+
+def _emit_patch(patches, it_lo, it_hi, sample_ptr, s,
+                ls, le, loop_mode, default_pan, dnv,
+                vib_speed, vib_depth, vib_rate, vib_wave):
+    """Append one patch dict covering IT-note range [it_lo, it_hi] inclusive."""
+    taud_lo = _it_note_to_taud(it_lo, clamp_low=(it_lo == 0))
+    taud_hi = _it_note_to_taud(it_hi, clamp_high=(it_hi == 119))
+    patches.append({
+        'pitch_start':         taud_lo,
+        'pitch_end':           taud_hi,
+        'volume_start':        0,
+        'volume_end':          63,
+        'sample_ptr':          sample_ptr,
+        'sample_length':       min(s.length, 65535),
+        'play_start':          0,
+        'loop_start':          ls,
+        'loop_end':            le,
+        'sampling_rate':       min(getattr(s, 'c5_speed', 8363), 65535),
+        'sample_detune':       0,
+        'loop_mode':           loop_mode,
+        'default_pan':         default_pan,
+        'default_note_volume': dnv,
+        'vibrato_speed':       vib_speed,
+        'vibrato_sweep':       0,                  # IT-side; FT2 sweep stays 0
+        'vibrato_depth':       vib_depth,
+        'vibrato_rate':        vib_rate,
+        'vibrato_waveform':    vib_wave,
+    })
 
 
 # ── Sample / instrument bin (same as s3m2taud) ────────────────────────────────
@@ -1150,13 +1322,29 @@ def build_sample_inst_bin_it(samples_or_proxy: list,
     sample_bin = bytearray(SAMPLEBIN_SIZE)
     offsets    = {}
     pos        = 0
+    # IT use_instruments mode points many Taud instrument slots at the same
+    # underlying sample object (e.g. seven "ChipBass.*" instruments all play
+    # "ChipBass.looped"). Write each distinct sample's PCM into the pool once and
+    # let every referencing slot share the offset, rather than emitting one
+    # identical copy per slot. `pool_order` records the distinct samples in
+    # ascending-offset order — the order taut.js's sample viewer expects SNam to
+    # follow (it dedupes instrument records by (ptr,len), sorts by ptr, and
+    # matches SNam[i+1] positionally — see taut.js buildSampleIndex).
+    written    = {}     # id(sample) -> pool offset already written
+    pool_order = []     # distinct sample objects, in pool (ascending-offset) order
     for idx, s in pcm_list:
+        shared = written.get(id(s))
+        if shared is not None:
+            offsets[idx] = shared
+            continue
         n = min(len(s.sample_data), SAMPLEBIN_SIZE - pos)
         if n <= 0:
             vprint(f"  warning: sample bin full, dropping '{s.name}'")
             offsets[idx] = 0; s.length = 0; continue
         sample_bin[pos:pos+n] = s.sample_data[:n]
         offsets[idx] = pos
+        written[id(s)] = pos
+        pool_order.append(s)
         if n < len(s.sample_data):
             vprint(f"  warning: '{s.name}' truncated {len(s.sample_data)} → {n}")
             s.length = n
@@ -1335,15 +1523,16 @@ def build_sample_inst_bin_it(samples_or_proxy: list,
         dct = idata.get('dct', 0) & 0x03
         dca = idata.get('dca', 0) & 0x03
         inst_bin[base + 195] = (dca << 2) | dct
-        # Byte 196: default note volume (per-trigger seed for rowVolume when
-        # no V column accompanies a fresh trigger). Replaces the old "fold
-        # sample.vol into IGV" trick — see terranmon byte 196 / TODO §2350.
+        # Byte 196: default note volume (per-trigger seed for the engine's
+        # noteVolume axis when no V column accompanies a fresh trigger).
+        # Replaces the old "fold sample.vol into IGV" trick — see terranmon
+        # byte 196 / TODO §2350.
         inst_bin[base + 196] = default_note_vol & 0xFF
         # Bytes 197..255: reserved (already zeroed).
 
         vprint(f"  instrument[{taud_idx}] '{s.name}' ptr:{ptr} c5spd:{s.c5_speed}")
 
-    return bytes(sample_bin) + bytes(inst_bin), offsets, ratio
+    return bytes(sample_bin) + bytes(inst_bin), offsets, ratio, pool_order
 
 
 # ── Pattern builder ───────────────────────────────────────────────────────────
@@ -1425,7 +1614,7 @@ def build_pattern_it(chunk_grid: list, ch_idx: int, default_pan: int,
         # Priority: explicit cell vol (vol-col 0-64) > vol-col slide > main-
         # effect vol override > nop. Per-trigger default volume now lives
         # in byte 196 of the instrument record (DNV); the engine seeds
-        # rowVolume from it when this row has no V column, so the converter
+        # noteVolume from it when this row has no V column, so the converter
         # still doesn't need to emit SEL_SET=Sv on plain trigger rows.
         if cell.volcol >= 0 and cell.volcol <= VC_VOL_HI:
             vol_sel, vol_value = SEL_SET, min(cell.volcol, 0x3F)
@@ -1573,22 +1762,176 @@ def _active_channels(h: ITHeader, patterns_rows: list) -> list:
         active = active[:NUM_VOICES]
     return active
 
+def _per_pattern_bxx_it(patterns_rows: list):
+    """Return callable(pat_idx) → (set_of_bxx_target_orders, kills_fallthrough)
+    for use by `detect_subsongs`. `kills_fallthrough` is True iff the pattern
+    carries a Bxx on its absolute last row — the unconditional terminating
+    jump idiom every tracker uses for "song ends here, loop back".
+    """
+    def fn(pat_idx: int):
+        if pat_idx < 0 or pat_idx >= len(patterns_rows):
+            return set(), False
+        grid, rows = patterns_rows[pat_idx]
+        targets = set()
+        last_row_has_b = False
+        for ch in range(64):
+            if ch >= len(grid): continue
+            ch_rows = grid[ch]
+            for r in range(min(rows, len(ch_rows))):
+                cell = ch_rows[r]
+                if cell.effect == EFF_B:
+                    targets.add(cell.effect_arg)
+                    if r == rows - 1:
+                        last_row_has_b = True
+        return targets, last_row_has_b
+    return fn
+
+
+def _build_song_payload(h: ITHeader, patterns_rows_template: list,
+                        positions: list, sample_ratio: dict,
+                        inst_vols: dict, active_channels: list,
+                        *, song_label: str = 'song') -> tuple:
+    """Build pattern bin + cue sheet + song-entry kwargs for one subsong.
+
+    Returns (pat_comp, cue_comp, entry_kwargs). The caller fills in
+    `song_offset` from the global layout before calling encode_song_entry.
+
+    `patterns_rows_template` is deep-copied so per-song stateful walks
+    (recall resolution, late-note-delay relocation, Bxx remap on chunks)
+    don't leak into the next subsong.
+    """
+    pats = copy.deepcopy(patterns_rows_template)
+    virtual_orders = [h.order_list[pos] for pos in positions]
+
+    vprint(f"  [{song_label}] resolving IT recalls…")
+    resolve_it_recalls(pats, virtual_orders, 64, h.link_gef,
+                       old_effects=h.old_effects)
+
+    init_speed, _ = find_initial_bpm_speed(pats, virtual_orders,
+                                           h.initial_speed, h.initial_tempo)
+    relocate_late_note_delays(pats, virtual_orders, 64, init_speed)
+
+    chunks, chunk_map, chunk_lens = split_patterns(pats)
+
+    C = len(active_channels)
+
+    # Cue list = expand each subsong position into chunk indices for its pattern.
+    # pos_to_cue maps the original order-list position → first cue in this song.
+    cue_list = []
+    pos_to_cue = {}
+    for pos in positions:
+        order = h.order_list[pos]
+        if order >= IT_ORD_END or order >= len(chunk_map):
+            continue
+        pos_to_cue[pos] = len(cue_list)
+        for ci in chunk_map[order]:
+            cue_list.append(ci)
+
+    # Bxx remap: source-position → cue-index. Cross-subsong Bxx targets clamp
+    # to cue 0 (loop the subsong rather than jump out of bounds). Only walk
+    # chunks that this song actually emits — avoids spurious warnings on
+    # patterns owned by other subsongs.
+    _remap_bc_effects(chunks, chunk_map, virtual_orders, pos_to_cue, C,
+                      default_target=0, warn_label=song_label,
+                      chunk_indices=set(cue_list))
+
+    speed, tempo = find_initial_bpm_speed(pats, virtual_orders,
+                                          h.initial_speed, h.initial_tempo)
+    tempo = max(25, min(280, tempo))
+    bpm_stored = (tempo - 25) & 0xFF
+    vprint(f"  [{song_label}] initial speed={speed}, tempo={tempo} BPM")
+
+    default_pans = [_it_default_pan(h.chnl_pan[ch]) for ch in active_channels]
+    total_taud_pats = len(cue_list) * C
+    if total_taud_pats > NUM_PATTERNS_MAX:
+        sys.exit(
+            f"error: [{song_label}] {len(cue_list)} cues × {C} channels = "
+            f"{total_taud_pats} > {NUM_PATTERNS_MAX} Taud pattern limit."
+        )
+
+    pat_bin = bytearray()
+    for ci in cue_list:
+        cg = chunks[ci]
+        for vi, ch in enumerate(active_channels):
+            pat_bin += build_pattern_it(cg, ch, default_pans[vi], inst_vols,
+                                          amiga_mode=not h.linear_slides)
+
+    pat_bin = rescale_offset_effects_per_slot(
+        bytes(pat_bin), len(cue_list), C, sample_ratio)
+
+    orig_count = len(cue_list) * C
+    pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(pat_bin, orig_count)
+    vprint(f"  [{song_label}] patterns: {orig_count} → {num_taud_pats} unique "
+           f"({orig_count - num_taud_pats} deduplicated)")
+
+    sheet = bytearray(NUM_CUES * CUE_SIZE)
+    for c in range(NUM_CUES):
+        sheet[c*CUE_SIZE:c*CUE_SIZE+CUE_SIZE] = encode_cue([], 0)
+
+    last_active = -1
+    len_cue_count = 0
+    for cue_idx, ci in enumerate(cue_list):
+        if cue_idx >= NUM_CUES: break
+        base_pat = cue_idx * C
+        pat_idx_list = [pat_remap[base_pat + vi] for vi in range(C)]
+        clen = chunk_lens[ci] if ci < len(chunk_lens) else PATTERN_ROWS
+        if clen < PATTERN_ROWS:
+            instr = cue_instruction_len(clen)
+            len_cue_count += 1
+        else:
+            instr = CUE_INST_NOP
+        sheet[cue_idx*CUE_SIZE:(cue_idx+1)*CUE_SIZE] = encode_cue(pat_idx_list, instr)
+        last_active = cue_idx
+
+    if last_active >= 0:
+        b30_existing = sheet[last_active * CUE_SIZE + 30]
+        if b30_existing == CUE_INST_LEN:
+            vprint(f"  [{song_label}] warning: last active cue {last_active} had LEN; "
+                   f"replaced with HALT (partial tail at song terminus)")
+        sheet[last_active * CUE_SIZE + 30] = CUE_INST_HALT
+        sheet[last_active * CUE_SIZE + 31] = 0x00
+    else:
+        sheet[30] = CUE_INST_HALT
+    if len_cue_count:
+        vprint(f"  [{song_label}] emitted {len_cue_count} LEN cue instruction(s) "
+               f"for partial-length patterns")
+
+    pat_comp = compress_blob(bytes(pat_bin), f"[{song_label}] pattern bin")
+    cue_comp = compress_blob(bytes(sheet),   f"[{song_label}] cue sheet")
+
+    flags_byte = 0x00 if h.linear_slides else 0x01
+    global_vol_taud = min(0xFF, round(h.global_vol * 255 / 128))
+    mixing_vol_taud = min(0xFF, round(h.mix_vol    * 255 / 128))
+
+    entry_kwargs = dict(
+        num_voices=C,
+        num_patterns=num_taud_pats,
+        bpm_stored=bpm_stored,
+        tick_rate=speed,
+        base_note=0xA000,   # C9
+        base_freq=8363.0,
+        flags_byte=flags_byte,
+        pat_bin_comp_size=len(pat_comp),
+        cue_sheet_comp_size=len(cue_comp),
+        global_vol=global_vol_taud,
+        mixing_vol=mixing_vol_taud,
+    )
+    return pat_comp, cue_comp, entry_kwargs
+
+
 def assemble_taud(h: ITHeader, samples: list, instruments: list,
                   patterns_rows: list, decompress: bool,
                   with_project_data: bool = True) -> bytes:
-    # ── Resolve IT recalls ───────────────────────────────────────────────────
-    vprint("  resolving IT recalls…")
-    resolve_it_recalls(patterns_rows, h.order_list, 64, h.link_gef,
-                       old_effects=h.old_effects)
+    # ── Active channels (shared across subsongs) ─────────────────────────────
+    active_channels = _active_channels(h, patterns_rows)
+    C = len(active_channels)
+    if C == 0:
+        sys.exit("error: no active channels found")
 
-    init_speed, _ = find_initial_bpm_speed(patterns_rows, h.order_list,
-                                           h.initial_speed, h.initial_tempo)
-    relocate_late_note_delays(patterns_rows, h.order_list, 64, init_speed)
-
-    # ── Check SBx chunk crossing (warn only) ─────────────────────────────────
+    # ── SBx chunk-crossing warning (informational only; pattern data is read,
+    #    not modified, so this is safe to do once over the shared template) ──
     for pi, (grid, rows) in enumerate(patterns_rows):
         if rows <= PATTERN_ROWS: continue
-        n_chunks = (rows + PATTERN_ROWS - 1) // PATTERN_ROWS
         for ch in range(64):
             if ch >= len(grid): continue
             loop_start_chunk = None
@@ -1605,41 +1948,15 @@ def assemble_taud(h: ITHeader, samples: list, instruments: list,
                                    f"chunk boundary (loops may misbehave)")
                             break
 
-    # ── Split patterns into 64-row chunks ────────────────────────────────────
-    vprint("  splitting patterns…")
-    chunks, chunk_map, chunk_lens = split_patterns(patterns_rows)
-
-    # ── Choose active channels ───────────────────────────────────────────────
-    active_channels = _active_channels(h, patterns_rows)
-    C = len(active_channels)
-    if C == 0:
-        sys.exit("error: no active channels found")
-
-    # ── Build the ordered list of (taud_chunk_idx, voice_idx) triples ────────
-    # Expand order list: each IT order → sequence of chunk indices for that pattern
-    taud_cue_list = []   # list of chunk_idx (source patterns, already chunked)
-    it_ord_to_taud_cue = {}   # first taud cue for IT order i
-
-    for oi, order in enumerate(h.order_list):
-        if order == IT_ORD_END:
-            break
-        if order == IT_ORD_SKIP:
-            continue
-        if order >= len(chunk_map):
-            continue
-        it_ord_to_taud_cue.setdefault(oi, len(taud_cue_list))
-        for ci in chunk_map[order]:
-            taud_cue_list.append(ci)
-
-    # ── Remap B effects ──────────────────────────────────────────────────────
-    _remap_bc_effects(chunks, chunk_map, h.order_list, it_ord_to_taud_cue,
-                      len(active_channels))
-
     # ── Build sample proxy list (0-indexed, slot 0 unused) ──────────────────
     # When use_instruments: map Taud instrument slots to samples via canonical_sample.
     # Pattern cells carry IT instrument numbers; for use_instruments mode, those
     # are instrument indices; we remap to samples below.
     # Taud only knows "instrument" slots (1-based, 8-bit). We lay samples in order.
+    # Map IT sample (0-based) → IXMP patch dict template used when building the
+    # per-instrument patch list. Populated by the use_instruments branch below.
+    it_sample_patch_meta = {}
+
     if h.use_instruments:
         # Build a proxy sample list where Taud inst slot = IT inst index,
         # resolved to the canonical sample. Slot 0 unused.
@@ -1734,159 +2051,167 @@ def assemble_taud(h: ITHeader, samples: list, instruments: list,
                 'dct':        inst.dct,
                 'dca':        inst.dca,
             }
-        sampleinst_raw, _, sample_ratio = build_sample_inst_bin_it(proxy, instr_data_by_slot)
+        # ── Ixmp: pool keyboard-referenced extra samples beyond slot 255 ───────
+        # IT instruments can map different IT notes to different samples via the
+        # keyboard table (IMPI+0x44). The canonical sample is already in the proxy
+        # at the instrument's Taud slot; extras (any other sample referenced in
+        # the keyboard) get appended past index 256 so build_sample_inst_bin_it
+        # pools them (its inst-record loop skips i >= 256 — see the same file).
+        # We then look up their bin offsets via the returned offsets dict and
+        # emit one Ixmp patch per (sample, contiguous-note-range) pair.
+        extras_keys = []   # ordered list of ('it_smp', si) — index into the proxy is 256 + position
+        for ii, inst in enumerate(instruments):
+            if inst is None: continue
+            canonical = inst.canonical_sample
+            kbd = getattr(inst, 'keyboard', None) or []
+            for kb_smp in kbd:
+                if kb_smp == 0 or kb_smp == canonical:
+                    continue
+                si = kb_smp - 1
+                if 0 <= si < len(samples) and samples[si] is not None and samples[si].sample_data:
+                    key = ('it_smp', si)
+                    if key not in extras_keys:
+                        extras_keys.append(key)
+        extras_base = len(proxy)
+        for key in extras_keys:
+            proxy.append(samples[key[1]])
+
+        sampleinst_raw, bin_offsets, sample_ratio, pool_order = build_sample_inst_bin_it(proxy, instr_data_by_slot)
+        # Map ('it_smp', si) → sample-bin offset.
+        extras_offsets = {key: bin_offsets.get(extras_base + j, 0)
+                          for j, key in enumerate(extras_keys)}
+        # Also include each canonical sample at its taud-slot offset so the patch
+        # builder can reuse them when an instrument's keyboard cell references the
+        # canonical sample at a non-canonical note range.
+        for ii, inst in enumerate(instruments):
+            if inst is None: continue
+            taud_slot = ii + 1
+            if taud_slot >= 256: continue
+            canon = inst.canonical_sample
+            if canon == 0: continue
+            si = canon - 1
+            if 0 <= si < len(samples) and samples[si] is not None and ('it_smp', si) not in extras_offsets:
+                # Look up the pool offset for the canonical via the proxy slot.
+                if taud_slot in bin_offsets:
+                    extras_offsets[('it_smp', si)] = bin_offsets[taud_slot]
     else:
-        # Samples referenced directly; proxy is samples list (0-based, slot 0 unused)
+        # Samples referenced directly; proxy is samples list (0-based, slot 0 unused).
+        # No instruments in the file → no multi-sample mapping → no Ixmp patches.
         proxy = [None] + list(samples)
         inst_vols = {
             i+1: min(s.vol, 0x3F)
             for i, s in enumerate(samples)
             if s is not None
         }
-        sampleinst_raw, _, sample_ratio = build_sample_inst_bin_it(proxy)
+        sampleinst_raw, bin_offsets, sample_ratio, pool_order = build_sample_inst_bin_it(proxy)
+        extras_offsets = {}
 
     assert len(sampleinst_raw) == SAMPLEINST_SIZE
 
     compressed   = compress_blob(sampleinst_raw, "sample+inst bin")
     comp_size    = len(compressed)
 
-    # ── BPM / speed ──────────────────────────────────────────────────────────
-    speed, tempo = find_initial_bpm_speed(patterns_rows, h.order_list,
-                                          h.initial_speed, h.initial_tempo)
-    tempo     = max(25, min(280, tempo))
-    bpm_stored = (tempo - 25) & 0xFF
-    vprint(f"  initial speed={speed}, tempo={tempo} BPM")
-
-    # ── Pattern bin ──────────────────────────────────────────────────────────
-    vprint("  building pattern bin…")
-    default_pans = [_it_default_pan(h.chnl_pan[ch]) for ch in active_channels]
-    total_taud_pats = len(taud_cue_list) * C
-    if total_taud_pats > NUM_PATTERNS_MAX:
-        sys.exit(
-            f"error: {len(taud_cue_list)} cues × {C} channels = "
-            f"{total_taud_pats} > {NUM_PATTERNS_MAX} Taud pattern limit."
-        )
-
-    pat_bin = bytearray()
-    for ci in taud_cue_list:
-        cg = chunks[ci]
-        for vi, ch in enumerate(active_channels):
-            pat_bin += build_pattern_it(cg, ch, default_pans[vi], inst_vols,
-                                          amiga_mode=not h.linear_slides)
-
-    # Rescale TOP_O sample-offset args per channel using the active slot's
-    # ratio (combined global + per-sample). Walks pat_bin in cue-major /
-    # channel-minor order, tracking the most recent inst byte seen on each
-    # channel — must run before deduplication so the channel state stays
-    # linear.
-    pat_bin = rescale_offset_effects_per_slot(
-        bytes(pat_bin), len(taud_cue_list), C, sample_ratio)
-
-    orig_count   = len(taud_cue_list) * C
-    pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(pat_bin, orig_count)
-    vprint(f"  patterns: {orig_count} → {num_taud_pats} unique "
-           f"({orig_count - num_taud_pats} deduplicated)")
-
-    # ── Cue sheet ────────────────────────────────────────────────────────────
-    vprint("  building cue sheet…")
-    song_offset = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY
-    sheet       = bytearray(NUM_CUES * CUE_SIZE)
-    for c in range(NUM_CUES):
-        sheet[c*CUE_SIZE:c*CUE_SIZE+CUE_SIZE] = encode_cue([], 0)
-
-    last_active = -1
-    len_cue_count = 0
-    for cue_idx, ci in enumerate(taud_cue_list):
-        if cue_idx >= NUM_CUES: break
-        base_pat = cue_idx * C
-        pats = [pat_remap[base_pat + vi] for vi in range(C)]
-        clen = chunk_lens[ci] if ci < len(chunk_lens) else PATTERN_ROWS
-        if clen < PATTERN_ROWS:
-            instr = cue_instruction_len(clen)
-            len_cue_count += 1
-        else:
-            instr = CUE_INST_NOP
-        sheet[cue_idx*CUE_SIZE:(cue_idx+1)*CUE_SIZE] = encode_cue(pats, instr)
-        last_active = cue_idx
-
-    if last_active >= 0:
-        # Halt overlays whatever LEN was on this cue. If both apply
-        # (the song terminates on a partial-tail chunk), the LEN is
-        # mooted by halt — warn so the user is aware.
-        b30_existing = sheet[last_active * CUE_SIZE + 30]
-        if b30_existing == CUE_INST_LEN:
-            vprint(f"  warning: last active cue {last_active} had LEN; "
-                   f"replaced with HALT (partial tail at song terminus)")
-        sheet[last_active * CUE_SIZE + 30] = CUE_INST_HALT
-        sheet[last_active * CUE_SIZE + 31] = 0x00
+    # ── Detect subsongs ──────────────────────────────────────────────────────
+    subsongs = detect_subsongs(h.order_list, _per_pattern_bxx_it(patterns_rows),
+                               terminators=(IT_ORD_END,),
+                               skip_marker=IT_ORD_SKIP)
+    if not subsongs:
+        # Degenerate file: every order is a terminator. Emit one empty subsong.
+        vprint("  warning: no traversable orders in source; emitting empty song")
+        subsongs = [{'entry': 0, 'positions': []}]
+    n_songs = len(subsongs)
+    if n_songs == 1:
+        vprint(f"  detected 1 song ({len(subsongs[0]['positions'])} orders)")
     else:
-        sheet[30] = CUE_INST_HALT
-    if len_cue_count:
-        vprint(f"  emitted {len_cue_count} LEN cue instruction(s) "
-               f"for partial-length patterns")
+        vprint(f"  detected {n_songs} subsongs:")
+        for i, ss in enumerate(subsongs):
+            vprint(f"    song {i}: entry@{ss['entry']}, {len(ss['positions'])} orders")
 
-    # ── Header ───────────────────────────────────────────────────────────────
-    sig    = (SIGNATURE + b' ' * 14)[:14]
+    # ── Build per-song payloads ──────────────────────────────────────────────
+    song_payloads = []   # list of (pat_comp, cue_comp, entry_kwargs)
+    for i, ss in enumerate(subsongs):
+        label = f"song {i}" if n_songs > 1 else "song"
+        song_payloads.append(_build_song_payload(
+            h, patterns_rows, ss['positions'],
+            sample_ratio, inst_vols, active_channels,
+            song_label=label))
 
-    # Compress pattern bin and cue sheet (per Taud spec)
-    pat_comp = compress_blob(bytes(pat_bin), "pattern bin")
-    cue_comp = compress_blob(bytes(sheet),   "cue sheet")
+    # ── Compute layout offsets and assemble song table ───────────────────────
+    song_table_off = TAUD_HEADER_SIZE + comp_size
+    first_song_off = song_table_off + TAUD_SONG_ENTRY * n_songs
 
-    # flags byte: bits 0-1 (ff) = tone mode. ff=1 (Amiga period slides) when IT's
-    # linear_slides flag is clear; ff=0 otherwise. Pan law is fixed engine-wide to
-    # the equal-energy — no `p` bit any more. Bit 2 was the old 'm' fadeout-zero
-    # policy flag and is now reserved (always 0); fadeout scaling is done per-instrument
-    # in this converter — see the fadeout pass-through below.
-    flags_byte = 0x00 if h.linear_slides else 0x01
-    # IT global/mix volumes are 0..128; rescale to Taud's 0..255 (clamped).
-    global_vol_taud = min(0xFF, round(h.global_vol * 255 / 128))
-    mixing_vol_taud = min(0xFF, round(h.mix_vol    * 255 / 128))
-    song_table = encode_song_entry(
-        song_offset=song_offset,
-        num_voices=C,
-        num_patterns=num_taud_pats,
-        bpm_stored=bpm_stored,
-        tick_rate=speed,
-        base_note=0xA000,   # C9
-        base_freq=8363.0,
-        flags_byte=flags_byte,
-        pat_bin_comp_size=len(pat_comp),
-        cue_sheet_comp_size=len(cue_comp),
-        global_vol=global_vol_taud,
-        mixing_vol=mixing_vol_taud,
-    )
-    assert len(song_table) == TAUD_SONG_ENTRY
+    song_table = bytearray()
+    cur_off = first_song_off
+    for pat_comp, cue_comp, entry_kwargs in song_payloads:
+        entry = encode_song_entry(song_offset=cur_off, **entry_kwargs)
+        assert len(entry) == TAUD_SONG_ENTRY
+        song_table += entry
+        cur_off += len(pat_comp) + len(cue_comp)
 
-    # Project Data (optional). IT distinguishes instruments from samples, so
-    # both INam and SNam can carry distinct content. Slot 0 is unused, so the
-    # tables are 1-indexed with an empty slot-0 entry.
+    # ── Project Data (optional) ──────────────────────────────────────────────
+    # IT distinguishes instruments from samples, so both INam and SNam can carry
+    # distinct content. Slot 0 is unused, so the tables are 1-indexed with an
+    # empty slot-0 entry.
     proj_data = b''
     proj_off  = 0
     if with_project_data:
         inst_names = [''] + [(inst.name if inst is not None else '')
                              for inst in instruments[:255]]
-        smp_names  = [''] + [(s.name if s is not None else '')
-                             for s in samples[:255]]
+        # SNam mirrors the deduplicated sample pool: one entry per distinct
+        # sample, in pool order, named after the sample itself. taut.js dedupes
+        # instrument records by (ptr,len), sorts ascending by ptr, and matches
+        # SNam[i+1] positionally to that list, so this ordering labels every
+        # sample correctly and a shared sample (e.g. "ChipBass.looped") appears
+        # exactly once instead of once per referencing instrument slot.
+        smp_names  = [''] + [(getattr(s, 'name', '') or '')
+                             for s in pool_order[:255]]
+
+        # Ixmp patches — only the use_instruments branch maps IT notes to multiple
+        # samples; the sample-mode branch has nothing to emit because there's no
+        # keyboard table on a raw IT sample.
+        ixmp_patches = {}
+        if h.use_instruments and extras_offsets:
+            for ii, inst in enumerate(instruments):
+                if inst is None: continue
+                taud_slot = ii + 1
+                if taud_slot >= 256: continue
+                patches = _build_it_ixmp_patches(inst, samples, extras_offsets)
+                if patches:
+                    ixmp_patches[taud_slot] = patches
+            if ixmp_patches:
+                vprint(f"  ixmp: {sum(len(p) for p in ixmp_patches.values())} "
+                       f"patches across {len(ixmp_patches)} instruments")
+
         proj_data = build_project_data(
             project_name=h.title,
             instrument_names=inst_names,
             sample_names=smp_names,
+            ixmp_patches=ixmp_patches or None,
         )
         if proj_data:
-            proj_off = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY \
-                       + len(pat_comp) + len(cue_comp)
+            proj_off = cur_off
             vprint(f"  project data: {len(proj_data)} bytes @ offset {proj_off}")
 
+    # ── Header ───────────────────────────────────────────────────────────────
+    sig = (SIGNATURE + b' ' * 14)[:14]
     header = (
         TAUD_MAGIC +
-        bytes([TAUD_VERSION, 1]) +
+        bytes([TAUD_VERSION, n_songs & 0xFF]) +
         struct.pack('<I', comp_size) +
         struct.pack('<I', proj_off) +
         sig
     )
     assert len(header) == TAUD_HEADER_SIZE
 
-    return header + compressed + song_table + pat_comp + cue_comp + proj_data
+    out = bytearray()
+    out += header
+    out += compressed
+    out += song_table
+    for pat_comp, cue_comp, _ in song_payloads:
+        out += pat_comp
+        out += cue_comp
+    out += proj_data
+    return bytes(out)
 
 
 # ── Main ──────────────────────────────────────────────────────────────────────

mod2taud.py

@@ -24,6 +24,7 @@ Effect support:
 """
 
 import argparse
+import copy
 import math
 import struct
 import sys
@@ -40,7 +41,7 @@ from taud_common import (
     J_SEMI_TABLE,
     d_arg_to_col, resample_linear, rescale_offset_effects, encode_cue, deduplicate_patterns,
     encode_song_entry, compress_blob,
-    build_project_data,
+    build_project_data, detect_subsongs,
 )
 
 
@@ -249,7 +250,7 @@ def period_to_taud_note(period: int) -> int:
     if period <= 0:
         return NOTE_NOP
     val = round(TAUD_C4 + 4096.0 * math.log2(PT_REFERENCE_PERIOD / period))
-    return max(1, min(0xFFFD, val))
+    return max(0x20, min(0xFFFF, val))
 
 
 # ── PT effect → Taud effect ──────────────────────────────────────────────────
@@ -591,7 +592,7 @@ def build_sample_inst_bin(samples: list) -> tuple:
 # PT hard-pans channels in LRRL order: 0=L 1=R 2=R 3=L (and tile for >4).
 def _default_channel_pan(ch_idx: int) -> int:
     side = (ch_idx % 4)
-    return 16 if side in (0, 3) else 47
+    return 8 if side in (0, 3) else 55
 
 
 def build_pattern(grid: list, ch_idx: int, default_pan: int,
@@ -702,99 +703,133 @@ def find_initial_bpm_speed(patterns: list, order_list: list) -> tuple:
     return speed, tempo
 
 
-def assemble_taud(mod: dict, with_project_data: bool = True) -> bytes:
-    samples    = mod['samples']
-    patterns   = mod['patterns']
-    order_list = mod['order_list']
-    n_channels = mod['n_channels']
-    n_patterns = mod['n_patterns']
-
-    if n_channels > NUM_VOICES:
-        vprint(f"  warning: MOD has {n_channels} channels; truncating to {NUM_VOICES}")
-        n_channels = NUM_VOICES
-
-    if n_patterns * n_channels > NUM_PATTERNS_MAX:
-        sys.exit(
-            f"error: {n_patterns} MOD patterns × {n_channels} channels = "
-            f"{n_patterns*n_channels} > {NUM_PATTERNS_MAX} Taud pattern limit.\n"
-            f"  Reduce the MOD to ≤ {NUM_PATTERNS_MAX // max(n_channels,1)} patterns."
-        )
-
-    vprint(f"  channels: {n_channels}, mod patterns: {n_patterns}, "
-           f"taud patterns: {n_patterns * n_channels}")
-
-    # Fold Cxx into row.vol_set so the volume column carries explicit set-volume.
-    # This is done in-place before recall resolution so Cxx with arg 0 still
-    # resolves to vol 0 (silence) rather than recalling another effect's memory.
-    for grid in patterns:
+def _per_pattern_bxx_mod(patterns: list, n_channels: int):
+    """Return callable(pat_idx) → (set_of_bxx_target_orders, kills_fallthrough)
+    for `detect_subsongs`. MOD patterns are 64 rows × n_channels; Bxx is
+    raw effect digit 0xB.
+    """
+    def fn(pat_idx: int):
+        if pat_idx < 0 or pat_idx >= len(patterns):
+            return set(), False
+        grid = patterns[pat_idx]
+        targets = set()
+        last_row_has_b = False
         for ch in range(min(n_channels, len(grid))):
-            for row in grid[ch]:
-                if row.effect == 0xC:
-                    row.vol_set = min(row.effect_arg, 0x3F)
-                    row.effect = 0
-                    row.effect_arg = 0
+            ch_rows = grid[ch]
+            for r in range(min(PATTERN_ROWS, len(ch_rows))):
+                cell = ch_rows[r]
+                if cell.effect == 0xB:
+                    targets.add(cell.effect_arg & 0xFF)
+                    if r == PATTERN_ROWS - 1:
+                        last_row_has_b = True
+        return targets, last_row_has_b
+    return fn
 
-    vprint("  resolving PT per-effect recalls…")
-    resolve_pt_recalls(patterns, order_list, n_channels)
 
-    init_speed, _ = find_initial_bpm_speed(patterns, order_list)
-    relocate_late_note_delays(patterns, order_list, n_channels, init_speed)
+def _build_song_payload_mod(mod: dict, patterns_template: list,
+                            positions: list, sample_ratio: dict,
+                            inst_vols: dict, n_channels: int,
+                            *, song_label: str = 'song') -> tuple:
+    """Build pattern bin + cue sheet + song-entry kwargs for one MOD subsong.
 
-    vprint("  building sample/instrument bin…")
-    sampleinst_raw, _offsets, sample_ratio = build_sample_inst_bin(samples)
-    assert len(sampleinst_raw) == SAMPLEINST_SIZE
+    `patterns_template` is deep-copied so per-song stateful transforms
+    (recall resolution, late-note-delay relocation, Bxx remap) don't leak
+    into the next subsong.
+    """
+    patterns = copy.deepcopy(patterns_template)
+    order_list = mod['order_list']
+    virtual_orders = [order_list[pos] for pos in positions]
 
-    compressed = compress_blob(sampleinst_raw, "sample+inst bin")
-    comp_size  = len(compressed)
+    vprint(f"  [{song_label}] resolving PT per-effect recalls…")
+    resolve_pt_recalls(patterns, virtual_orders, n_channels)
 
-    speed, tempo = find_initial_bpm_speed(patterns, order_list)
+    init_speed, _ = find_initial_bpm_speed(patterns, virtual_orders)
+    relocate_late_note_delays(patterns, virtual_orders, n_channels, init_speed)
+
+    speed, tempo = find_initial_bpm_speed(patterns, virtual_orders)
     tempo = max(25, min(280, tempo))
     bpm_stored = (tempo - 25) & 0xFF
-    vprint(f"  initial speed={speed}, tempo(BPM)={tempo}")
+    vprint(f"  [{song_label}] initial speed={speed}, tempo(BPM)={tempo}")
 
-    song_offset = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY
+    n_patterns = mod['n_patterns']
 
-    sig = (SIGNATURE + b' ' * 14)[:14]
+    # Cue list and pos→cue mapping, skipping orders that aren't valid pattern refs.
+    cue_list = []
+    pos_to_cue = {}
+    for pos in positions:
+        order = order_list[pos]
+        if order >= n_patterns:
+            continue
+        pos_to_cue[pos] = len(cue_list)
+        cue_list.append(order)
+
+    # Densely renumber the patterns this song uses.
+    used_ordered = []
+    seen = set()
+    for src_pat in cue_list:
+        if src_pat not in seen:
+            used_ordered.append(src_pat)
+            seen.add(src_pat)
+    pat_idx_remap = {src: i for i, src in enumerate(used_ordered)}
+    P_used = len(used_ordered)
+
+    if P_used * n_channels > NUM_PATTERNS_MAX:
+        sys.exit(f"error: [{song_label}] {P_used} patterns × {n_channels} channels = "
+                 f"{P_used*n_channels} > {NUM_PATTERNS_MAX} Taud pattern limit.")
+
+    # Bxx remap on the patterns this song actually emits.
+    crossings = 0
+    for src_pat in used_ordered:
+        if src_pat >= len(patterns): continue
+        grid = patterns[src_pat]
+        for ch in range(min(n_channels, len(grid))):
+            for row in grid[ch]:
+                if row.effect == 0xB:
+                    if row.effect_arg in pos_to_cue:
+                        row.effect_arg = pos_to_cue[row.effect_arg] & 0xFF
+                    else:
+                        crossings += 1
+                        row.effect_arg = 0
+    if crossings:
+        vprint(f"  warning: [{song_label}]: {crossings} Bxx target(s) cross "
+               f"subsong boundary; clamped to cue 0")
 
-    vprint("  building pattern bin…")
-    inst_vols = {
-        i + 1: min(s.volume, 0x3F)
-        for i, s in enumerate(samples)
-        if s.sample_data
-    }
     pat_bin = bytearray()
-    for pi in range(n_patterns):
-        grid = patterns[pi]
+    for src_pat in used_ordered:
+        grid = patterns[src_pat]
         for ch in range(n_channels):
             default_pan = _default_channel_pan(ch)
             pat_bin += build_pattern(grid, ch, default_pan, inst_vols)
-    assert len(pat_bin) == n_patterns * n_channels * PATTERN_BYTES
-
-    # Rescale TOP_O sample-offset args if samples were globally downsampled.
     pat_bin = rescale_offset_effects(bytes(pat_bin), sample_ratio)
 
-    vprint("  deduplicating patterns…")
-    orig_count = n_patterns * n_channels
+    orig_count = P_used * n_channels
     pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(pat_bin, orig_count)
-    vprint(f"  patterns: {orig_count} → {num_taud_pats} unique "
+    vprint(f"  [{song_label}] patterns: {orig_count} → {num_taud_pats} unique "
            f"({orig_count - num_taud_pats} deduplicated)")
 
-    vprint("  building cue sheet…")
-    cue_sheet = build_cue_sheet(order_list, n_patterns, n_channels, pat_remap)
-    assert len(cue_sheet) == NUM_CUES * CUE_SIZE
+    sheet = bytearray(NUM_CUES * CUE_SIZE)
+    for c in range(NUM_CUES):
+        sheet[c*CUE_SIZE:c*CUE_SIZE+CUE_SIZE] = encode_cue([], 0)
 
-    pat_comp = compress_blob(bytes(pat_bin),   "pattern bin")
-    cue_comp = compress_blob(bytes(cue_sheet), "cue sheet")
+    last_active = -1
+    for cue_idx, src_pat in enumerate(cue_list):
+        if cue_idx >= NUM_CUES: break
+        new_pat_idx = pat_idx_remap[src_pat]
+        orig_pats = [new_pat_idx * n_channels + v for v in range(n_channels)]
+        sheet[cue_idx*CUE_SIZE:(cue_idx+1)*CUE_SIZE] = encode_cue(
+            [pat_remap[p] for p in orig_pats], 0)
+        last_active = cue_idx
+
+    if last_active >= 0:
+        sheet[last_active * CUE_SIZE + 30] = 0x01
+    else:
+        sheet[30] = 0x01
+
+    pat_comp = compress_blob(bytes(pat_bin), f"[{song_label}] pattern bin")
+    cue_comp = compress_blob(bytes(sheet),   f"[{song_label}] cue sheet")
 
-    # ProTracker is Amiga-period-based by definition, so we set ff=1 (bits 0-1) so
-    # the engine applies coarse pitch slides in period space (recovers PT's
-    # characteristic non-linear pitch character). Pan law is fixed to the
-    # equal-energy engine-wide. PT has no instrument-level fadeout, so every Taud
-    # instrument carries fadeout=0 ("no fade") — notes retire on sample-end or
-    # pattern note-cut instead, which matches PT semantics.
     flags_byte = GLOBAL_FLAGS_AMIGA_FREQ | GLOBAL_FLAGS_A500_INTP
-    song_table = encode_song_entry(
-        song_offset=song_offset,
+    entry_kwargs = dict(
         num_voices=n_channels,
         num_patterns=num_taud_pats,
         bpm_stored=bpm_stored,
@@ -807,7 +842,82 @@ def assemble_taud(mod: dict, with_project_data: bool = True) -> bytes:
         global_vol=0xFF,
         mixing_vol=180,
     )
-    assert len(song_table) == TAUD_SONG_ENTRY
+    return pat_comp, cue_comp, entry_kwargs
+
+
+def assemble_taud(mod: dict, with_project_data: bool = True) -> bytes:
+    samples    = mod['samples']
+    patterns   = mod['patterns']
+    order_list = mod['order_list']
+    n_channels = mod['n_channels']
+    n_patterns = mod['n_patterns']
+
+    if n_channels > NUM_VOICES:
+        vprint(f"  warning: MOD has {n_channels} channels; truncating to {NUM_VOICES}")
+        n_channels = NUM_VOICES
+    vprint(f"  channels: {n_channels}, mod patterns: {n_patterns}")
+
+    # Fold Cxx into row.vol_set so the volume column carries explicit set-volume.
+    # This is non-stateful (doesn't depend on order list) so it runs once on the
+    # shared template; per-song deepcopies inherit the folded form.
+    for grid in patterns:
+        for ch in range(min(n_channels, len(grid))):
+            for row in grid[ch]:
+                if row.effect == 0xC:
+                    row.vol_set = min(row.effect_arg, 0x3F)
+                    row.effect = 0
+                    row.effect_arg = 0
+
+    vprint("  building sample/instrument bin…")
+    sampleinst_raw, _offsets, sample_ratio = build_sample_inst_bin(samples)
+    assert len(sampleinst_raw) == SAMPLEINST_SIZE
+    compressed = compress_blob(sampleinst_raw, "sample+inst bin")
+    comp_size  = len(compressed)
+
+    inst_vols = {
+        i + 1: min(s.volume, 0x3F)
+        for i, s in enumerate(samples)
+        if s.sample_data
+    }
+
+    # ── Detect subsongs ──────────────────────────────────────────────────────
+    # MOD shares IT/S3M's 0xFF-end / 0xFE-skip convention; orders ≥ n_patterns
+    # are also unplayable and treated as skips by the player (build_cue_sheet).
+    skip_set = set([0xFE]) | set(range(n_patterns, 256))
+    subsongs = detect_subsongs(order_list,
+                               _per_pattern_bxx_mod(patterns, n_channels),
+                               terminators=(0xFF,),
+                               skip_marker=skip_set)
+    if not subsongs:
+        vprint("  warning: no traversable orders in source; emitting empty song")
+        subsongs = [{'entry': 0, 'positions': []}]
+    n_songs = len(subsongs)
+    if n_songs == 1:
+        vprint(f"  detected 1 song ({len(subsongs[0]['positions'])} orders)")
+    else:
+        vprint(f"  detected {n_songs} subsongs:")
+        for i, ss in enumerate(subsongs):
+            vprint(f"    song {i}: entry@{ss['entry']}, {len(ss['positions'])} orders")
+
+    # ── Build per-song payloads ──────────────────────────────────────────────
+    song_payloads = []
+    for i, ss in enumerate(subsongs):
+        label = f"song {i}" if n_songs > 1 else "song"
+        song_payloads.append(_build_song_payload_mod(
+            mod, patterns, ss['positions'], sample_ratio, inst_vols,
+            n_channels, song_label=label))
+
+    # ── Layout offsets and song table ────────────────────────────────────────
+    song_table_off = TAUD_HEADER_SIZE + comp_size
+    first_song_off = song_table_off + TAUD_SONG_ENTRY * n_songs
+
+    song_table = bytearray()
+    cur_off = first_song_off
+    for pat_comp, cue_comp, entry_kwargs in song_payloads:
+        entry = encode_song_entry(song_offset=cur_off, **entry_kwargs)
+        assert len(entry) == TAUD_SONG_ENTRY
+        song_table += entry
+        cur_off += len(pat_comp) + len(cue_comp)
 
     # Project Data (optional). MOD samples *are* its instruments — the names
     # populate both INam and SNam (1-based; slot 0 empty).
@@ -821,20 +931,28 @@ def assemble_taud(mod: dict, with_project_data: bool = True) -> bytes:
             sample_names=names,
         )
         if proj_data:
-            proj_off = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY \
-                       + len(pat_comp) + len(cue_comp)
+            proj_off = cur_off
             vprint(f"  project data: {len(proj_data)} bytes @ offset {proj_off}")
 
+    sig = (SIGNATURE + b' ' * 14)[:14]
     header = (
         TAUD_MAGIC +
-        bytes([TAUD_VERSION, 1]) +
+        bytes([TAUD_VERSION, n_songs & 0xFF]) +
         struct.pack('<I', comp_size) +
         struct.pack('<I', proj_off) +
         sig
     )
     assert len(header) == TAUD_HEADER_SIZE
 
-    return header + compressed + song_table + pat_comp + cue_comp + proj_data
+    out = bytearray()
+    out += header
+    out += compressed
+    out += song_table
+    for pat_comp, cue_comp, _ in song_payloads:
+        out += pat_comp
+        out += cue_comp
+    out += proj_data
+    return bytes(out)
 
 
 # ── Main ─────────────────────────────────────────────────────────────────────

mon2taud.py

@@ -22,6 +22,7 @@ Limits: numVoices ≤ 20, numPatterns × numVoices ≤ 4095.
 """
 
 import argparse
+import copy
 import struct
 import sys
 
@@ -35,7 +36,7 @@ from taud_common import (
     SEL_SET, SEL_FINE,
     J_SEMI_TABLE,
     encode_cue, deduplicate_patterns, encode_song_entry, compress_blob,
-    build_project_data,
+    build_project_data, detect_subsongs,
 )
 
 
@@ -138,7 +139,7 @@ def mon_note_to_taud(mon_note: int) -> int:
     if mon_note == 0x7F:
         return NOTE_CUT
     val = TAUD_C4 + round((mon_note - MON_NOTE_C4) * 4096.0 / 12.0)
-    return max(1, min(0xFFFD, val))
+    return max(0x20, min(0xFFFF, val))
 
 
 # ── Effect mapping (Monotone 3-bit code + 6-bit data → Taud) ─────────────────
@@ -219,8 +220,8 @@ def build_sample_inst_bin() -> bytes:
     inst_bin[base + 183] = 0xFF                                          # filter resonance off
     inst_bin[base + 186] = 0x01                                          # NNA: cut
     # Monotone has no per-sample default volume concept (only one synth
-    # voice, no V column overrides). Set DNV to full so triggers get the
-    # full 0x3F rowVolume; the IGV above provides the actual attenuation.
+    # voice, no V column overrides). Set DNV to full so triggers seed
+    # noteVolume at 0x3F; the IGV above provides the actual attenuation.
     inst_bin[base + 196] = 0xFF                                          # DNV: full
 
     return bytes(sample_bin) + bytes(inst_bin)
@@ -304,6 +305,130 @@ def find_initial_speed(patterns: list, order_list: list, num_voices: int) -> int
 
 # ── Top-level assembly ───────────────────────────────────────────────────────
 
+def _per_pattern_bxx_mon(patterns: list, num_voices: int):
+    """Return callable(pat_idx) → (set_of_bxx_target_orders, kills_fallthrough)
+    for `detect_subsongs`. Monotone effect index 5 is 'B' (position jump);
+    arg is 6 bits (0..63). Patterns are 64 rows × num_voices. `grid[v][r]`.
+    """
+    def fn(pat_idx: int):
+        if pat_idx < 0 or pat_idx >= len(patterns):
+            return set(), False
+        grid = patterns[pat_idx]
+        targets = set()
+        last_row_has_b = False
+        for v in range(min(num_voices, len(grid))):
+            v_rows = grid[v]
+            for r in range(min(MON_PATTERN_ROWS, len(v_rows))):
+                cell = v_rows[r]
+                if cell.effect == 5:
+                    targets.add(cell.effect_arg & 0x3F)
+                    if r == MON_PATTERN_ROWS - 1:
+                        last_row_has_b = True
+        return targets, last_row_has_b
+    return fn
+
+
+def _build_song_payload_mon(mon: dict, patterns_template: list,
+                            positions: list, num_voices: int,
+                            *, song_label: str = 'song') -> tuple:
+    """Build pattern bin + cue sheet + song-entry kwargs for one Monotone
+    subsong. Mutates a deepcopy of the patterns to remap Bxx targets to
+    per-song cue indices.
+    """
+    patterns = copy.deepcopy(patterns_template)
+    order_list = mon['order_list']
+    n_patterns = mon['n_patterns']
+    virtual_orders = [order_list[pos] for pos in positions]
+
+    speed = find_initial_speed(patterns, virtual_orders, num_voices)
+    vprint(f"  [{song_label}] initial speed (ticks/row): {speed}")
+
+    cue_list = []
+    pos_to_cue = {}
+    for pos in positions:
+        order = order_list[pos]
+        if order >= n_patterns:
+            continue
+        pos_to_cue[pos] = len(cue_list)
+        cue_list.append(order)
+
+    used_ordered = []
+    seen = set()
+    for src_pat in cue_list:
+        if src_pat not in seen:
+            used_ordered.append(src_pat)
+            seen.add(src_pat)
+    pat_idx_remap = {src: i for i, src in enumerate(used_ordered)}
+    P_used = len(used_ordered)
+
+    if P_used * num_voices > NUM_PATTERNS_MAX:
+        sys.exit(f"error: [{song_label}] {P_used} patterns × {num_voices} voices = "
+                 f"{P_used*num_voices} > {NUM_PATTERNS_MAX} Taud pattern limit.")
+
+    # Bxx remap: source position → cue index. Cross-song clamps to cue 0.
+    crossings = 0
+    for src_pat in used_ordered:
+        if src_pat >= len(patterns): continue
+        grid = patterns[src_pat]
+        for v in range(min(num_voices, len(grid))):
+            for row in grid[v]:
+                if row.effect == 5:
+                    if row.effect_arg in pos_to_cue:
+                        row.effect_arg = pos_to_cue[row.effect_arg] & 0x3F
+                    else:
+                        crossings += 1
+                        row.effect_arg = 0
+    if crossings:
+        vprint(f"  warning: [{song_label}]: {crossings} Bxx target(s) cross "
+               f"subsong boundary; clamped to cue 0")
+
+    pat_bin = bytearray()
+    for src_pat in used_ordered:
+        grid = patterns[src_pat]
+        for v in range(num_voices):
+            pat_bin += build_taud_pattern(grid, v)
+
+    orig_count = P_used * num_voices
+    pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(bytes(pat_bin), orig_count)
+    vprint(f"  [{song_label}] patterns: {orig_count} → {num_taud_pats} unique "
+           f"({orig_count - num_taud_pats} deduplicated)")
+
+    sheet = bytearray(NUM_CUES * CUE_SIZE)
+    for c in range(NUM_CUES):
+        sheet[c*CUE_SIZE:(c+1)*CUE_SIZE] = encode_cue([], 0)
+
+    last_active = -1
+    for cue_idx, src_pat in enumerate(cue_list):
+        if cue_idx >= NUM_CUES: break
+        new_pat_idx = pat_idx_remap[src_pat]
+        orig_pats = [new_pat_idx * num_voices + v for v in range(num_voices)]
+        sheet[cue_idx*CUE_SIZE:(cue_idx+1)*CUE_SIZE] = encode_cue(
+            [pat_remap[p] for p in orig_pats], 0)
+        last_active = cue_idx
+    if last_active >= 0:
+        sheet[last_active * CUE_SIZE + 30] = 0x01
+
+    pat_comp = compress_blob(bytes(pat_bin), f"[{song_label}] pattern bin")
+    cue_comp = compress_blob(bytes(sheet),   f"[{song_label}] cue sheet")
+
+    flags_byte = GLOBAL_FLAGS_LINEAR_FREQ | GLOBAL_FLAGS_NO_INTERPOLATION
+    bpm_stored = 150 - 25
+    entry_kwargs = dict(
+        num_voices=num_voices,
+        num_patterns=num_taud_pats,
+        bpm_stored=bpm_stored,
+        tick_rate=speed,
+        base_note=0xA000,
+        base_freq=SQUARE_C2SPD,
+        flags_byte=flags_byte,
+        pat_bin_comp_size=len(pat_comp),
+        cue_sheet_comp_size=len(cue_comp),
+        global_vol=0xFF,
+        mixing_vol=round(180 / num_voices),
+    )
+    return pat_comp, cue_comp, entry_kwargs
+
+
 def assemble_taud(mon: dict, with_project_data: bool = True) -> bytes:
     num_voices = mon['num_voices']
     patterns   = mon['patterns']
@@ -313,18 +438,7 @@ def assemble_taud(mon: dict, with_project_data: bool = True) -> bytes:
     if num_voices > NUM_VOICES:
         vprint(f"  warning: {num_voices} voices > {NUM_VOICES}; truncating")
         num_voices = NUM_VOICES
-
-    if n_patterns * num_voices > NUM_PATTERNS_MAX:
-        sys.exit(
-            f"error: {n_patterns} patterns × {num_voices} voices = "
-            f"{n_patterns*num_voices} > {NUM_PATTERNS_MAX} Taud limit"
-        )
-
-    vprint(f"  voices: {num_voices}, mon patterns: {n_patterns}, "
-           f"taud patterns: {n_patterns * num_voices}")
-
-    speed = find_initial_speed(patterns, order_list, num_voices)
-    vprint(f"  initial speed (ticks/row): {speed}")
+    vprint(f"  voices: {num_voices}, mon patterns: {n_patterns}")
 
     vprint("  building sample/instrument bin…")
     sampleinst_raw = build_sample_inst_bin()
@@ -332,53 +446,44 @@ def assemble_taud(mon: dict, with_project_data: bool = True) -> bytes:
     compressed = compress_blob(sampleinst_raw, "sample+inst bin")
     comp_size  = len(compressed)
 
-    vprint("  building pattern bin…")
-    pat_bin = bytearray()
-    for pi in range(n_patterns):
-        grid = patterns[pi]
-        for v in range(num_voices):
-            pat_bin += build_taud_pattern(grid, v)
-    assert len(pat_bin) == n_patterns * num_voices * PATTERN_BYTES
+    # ── Detect subsongs ──────────────────────────────────────────────────────
+    # Monotone strips 0xFF (skip) markers during parse, so the order list is
+    # already a clean sequence of pattern indices. No terminator/skip values
+    # to feed the detector — subsongs only emerge from the Bxx graph.
+    skip_set = set(range(n_patterns, 256))   # invalid pattern refs → skip
+    subsongs = detect_subsongs(order_list,
+                               _per_pattern_bxx_mon(patterns, num_voices),
+                               terminators=(),
+                               skip_marker=skip_set)
+    if not subsongs:
+        vprint("  warning: no traversable orders in source; emitting empty song")
+        subsongs = [{'entry': 0, 'positions': []}]
+    n_songs = len(subsongs)
+    if n_songs == 1:
+        vprint(f"  detected 1 song ({len(subsongs[0]['positions'])} orders)")
+    else:
+        vprint(f"  detected {n_songs} subsongs:")
+        for i, ss in enumerate(subsongs):
+            vprint(f"    song {i}: entry@{ss['entry']}, {len(ss['positions'])} orders")
 
-    vprint("  deduplicating patterns…")
-    orig_count = n_patterns * num_voices
-    pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(bytes(pat_bin), orig_count)
-    vprint(f"  patterns: {orig_count} → {num_taud_pats} unique "
-           f"({orig_count - num_taud_pats} deduplicated)")
+    # ── Build per-song payloads ──────────────────────────────────────────────
+    song_payloads = []
+    for i, ss in enumerate(subsongs):
+        label = f"song {i}" if n_songs > 1 else "song"
+        song_payloads.append(_build_song_payload_mon(
+            mon, patterns, ss['positions'], num_voices, song_label=label))
 
-    vprint("  building cue sheet…")
-    cue_sheet = build_cue_sheet(order_list, num_voices, pat_remap)
-    assert len(cue_sheet) == NUM_CUES * CUE_SIZE
+    # ── Layout offsets and song table ────────────────────────────────────────
+    song_table_off = TAUD_HEADER_SIZE + comp_size
+    first_song_off = song_table_off + TAUD_SONG_ENTRY * n_songs
 
-    pat_comp = compress_blob(bytes(pat_bin),   "pattern bin")
-    cue_comp = compress_blob(bytes(cue_sheet), "cue sheet")
-
-    sig = (SIGNATURE + b' ' * 14)[:14]
-    song_offset = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY
-
-    # BPM 150 + ticks=mon_speed → row rate = 60/mon_speed (matches Monotone).
-    bpm_stored = 150 - 25
-    # Linear-frequency tone mode (ff=2) so 1xx/2xx/3xx Hz/tick semantics survive verbatim.
-    # Pan law is fixed engine-wide to the equal-energy (no flag). Monotone has no
-    # instrument-level fadeout, so every Taud instrument carries fadeout=0 ("no fade") —
-    # notes retire on sample-end or pattern note-cut instead.
-    flags_byte = GLOBAL_FLAGS_LINEAR_FREQ | GLOBAL_FLAGS_NO_INTERPOLATION
-
-    song_table = encode_song_entry(
-        song_offset       = song_offset,
-        num_voices        = num_voices,
-        num_patterns      = num_taud_pats,
-        bpm_stored        = bpm_stored,
-        tick_rate         = speed,
-        base_note         = 0xA000,
-        base_freq         = SQUARE_C2SPD,
-        flags_byte        = flags_byte,
-        pat_bin_comp_size = len(pat_comp),
-        cue_sheet_comp_size = len(cue_comp),
-        global_vol        = 0xFF,
-        mixing_vol        = round(180 / num_voices),
-    )
-    assert len(song_table) == TAUD_SONG_ENTRY
+    song_table = bytearray()
+    cur_off = first_song_off
+    for pat_comp, cue_comp, entry_kwargs in song_payloads:
+        entry = encode_song_entry(song_offset=cur_off, **entry_kwargs)
+        assert len(entry) == TAUD_SONG_ENTRY
+        song_table += entry
+        cur_off += len(pat_comp) + len(cue_comp)
 
     # Project Data (optional). Monotone has no title, no user instruments and
     # no per-sample names, but we still emit one identifying entry so the
@@ -391,21 +496,28 @@ def assemble_taud(mon: dict, with_project_data: bool = True) -> bytes:
             sample_names=['', 'PC speaker square'],
         )
         if proj_data:
-            proj_off = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY \
-                       + len(pat_comp) + len(cue_comp)
+            proj_off = cur_off
             vprint(f"  project data: {len(proj_data)} bytes @ offset {proj_off}")
 
-    # Header: magic, version, num_songs=1, comp_size of sample+inst, projOff, sig.
+    sig = (SIGNATURE + b' ' * 14)[:14]
     header = (
         TAUD_MAGIC
-        + bytes([TAUD_VERSION, 1])
+        + bytes([TAUD_VERSION, n_songs & 0xFF])
         + struct.pack('<I', comp_size)
         + struct.pack('<I', proj_off)
         + sig
     )
     assert len(header) == TAUD_HEADER_SIZE
 
-    return header + compressed + song_table + pat_comp + cue_comp + proj_data
+    out = bytearray()
+    out += header
+    out += compressed
+    out += song_table
+    for pat_comp, cue_comp, _ in song_payloads:
+        out += pat_comp
+        out += cue_comp
+    out += proj_data
+    return bytes(out)
 
 
 # ── Main ─────────────────────────────────────────────────────────────────────

s3m2taud.py

@@ -25,6 +25,7 @@ Effect support:
 """
 
 import argparse
+import copy
 import math
 import struct
 import sys
@@ -44,7 +45,7 @@ from taud_common import (
     J_SEMI_TABLE,
     d_arg_to_col, resample_linear, rescale_offset_effects, encode_cue, deduplicate_patterns,
     normalise_sample, encode_song_entry, compress_blob,
-    build_project_data,
+    build_project_data, detect_subsongs,
 )
 
 
@@ -137,7 +138,11 @@ def parse_instruments(data: bytes, h: S3MHeader) -> list:
             continue
         inst = S3MInstrument()
         inst.itype    = data[ptr]
-        inst.filename = data[ptr+1:ptr+13].rstrip(b'\x00').decode('latin-1', errors='replace')
+        # 12-byte DOS filename field; null-terminated with possible trailing
+        # garbage after the terminator (ST3 doesn't zero the tail). Truncate at
+        # the first null. This field carries the per-sample short name (e.g.
+        # 'HIT1') as distinct from the 28-byte title at 0x30.
+        inst.filename = data[ptr+1:ptr+13].split(b'\x00', 1)[0].decode('latin-1', errors='replace')
         # memseg: 3 bytes at offsets 0x0D,0x0E,0x0F — high byte first (quirk)
         memseg_hi  = data[ptr + 0x0D]
         memseg_lo  = struct.unpack_from('<H', data, ptr + 0x0E)[0]
@@ -233,7 +238,7 @@ def encode_note(s3m_note: int) -> int:
         return NOTE_NOP
     semitones = (octave - 4) * 12 + pitch
     val = round(TAUD_C4 + semitones * 4096 / 12)
-    return max(1, min(0xFFFD, val))
+    return max(0x20, min(0xFFFF, val))
 
 
 def encode_effect(cmd: int, arg: int, ch: int = 0, row: int = 0,
@@ -724,101 +729,146 @@ def find_initial_bpm_speed(patterns: list, order_list: list,
     return speed, tempo
 
 
-def assemble_taud(h: S3MHeader, instruments: list, patterns: list,
-                  with_project_data: bool = True) -> bytes:
-    # Determine active channels (bit7 clear = enabled)
-    active_channels = [i for i, cs in enumerate(h.channel_settings)
-                       if i < 32 and not (cs & 0x80)][:NUM_VOICES]
-    C = len(active_channels)
-    P = len(patterns)
+def _per_pattern_bxx_s3m(patterns: list):
+    """Return callable(pat_idx) → (set_of_bxx_target_orders, kills_fallthrough)
+    for `detect_subsongs`. `kills_fallthrough` is True iff the pattern carries
+    a Bxx on its absolute last row (the unconditional terminating-jump idiom).
+    S3M patterns are always 64 rows.
+    """
+    def fn(pat_idx: int):
+        if pat_idx < 0 or pat_idx >= len(patterns):
+            return set(), False
+        grid = patterns[pat_idx]
+        targets = set()
+        last_row_has_b = False
+        for ch in range(min(32, len(grid))):
+            ch_rows = grid[ch]
+            for r in range(min(PATTERN_ROWS, len(ch_rows))):
+                cell = ch_rows[r]
+                if getattr(cell, 'effect', 0) == EFF_B:
+                    targets.add(cell.effect_arg)
+                    if r == PATTERN_ROWS - 1:
+                        last_row_has_b = True
+        return targets, last_row_has_b
+    return fn
 
-    if P * C > NUM_PATTERNS_MAX:
-        sys.exit(
-            f"error: {P} S3M patterns × {C} channels = {P*C} > {NUM_PATTERNS_MAX} Taud pattern limit.\n"
-            f"  Reduce the S3M to ≤ {NUM_PATTERNS_MAX // max(C,1)} patterns, or mute "
-            f"channels to bring active count below {NUM_PATTERNS_MAX // max(P,1) + 1}."
-        )
 
-    vprint(f"  channels: {C}, s3m patterns: {P}, taud patterns: {P*C}")
+def _build_song_payload_s3m(h: S3MHeader, patterns_template: list,
+                            positions: list, sample_ratio: dict,
+                            inst_vols: dict, active_channels: list,
+                            *, song_label: str = 'song') -> tuple:
+    """Build pattern bin + cue sheet + song-entry kwargs for one subsong.
 
-    # Resolve ST3 shared-memory recalls (D/E/F/I/J/K/L/Q/R/S with $00 arg)
-    # before any per-row encoding, so cohort-aware Taud effects see explicit
-    # arguments. Mutates patterns in place.
-    vprint("  resolving ST3 shared-memory recalls…")
-    resolve_st3_recalls(patterns, h.order_list, 32)
-    warn_st3_quirks(patterns, h.order_list, 32)
+    Returns (pat_comp, cue_comp, entry_kwargs). The caller fills in
+    `song_offset` from the global layout. `patterns_template` is deep-copied
+    so per-song stateful walks (recall resolution, late-note-delay
+    relocation, Bxx remap) don't leak into the next subsong.
+    """
+    pats = copy.deepcopy(patterns_template)
+    virtual_orders = [h.order_list[pos] for pos in positions]
 
-    init_speed, _ = find_initial_bpm_speed(patterns, h.order_list,
+    vprint(f"  [{song_label}] resolving ST3 shared-memory recalls…")
+    resolve_st3_recalls(pats, virtual_orders, 32)
+    warn_st3_quirks(pats, virtual_orders, 32)
+
+    init_speed, _ = find_initial_bpm_speed(pats, virtual_orders,
                                            h.initial_speed, h.initial_tempo)
-    relocate_late_note_delays(patterns, h.order_list, 32, init_speed)
+    relocate_late_note_delays(pats, virtual_orders, 32, init_speed)
 
-    # Build sample+instrument bin
-    vprint("  building sample/instrument bin…")
-    sampleinst_raw, _offsets, sample_ratio = build_sample_inst_bin(instruments)
-    assert len(sampleinst_raw) == SAMPLEINST_SIZE
-
-    # Compress
-    compressed = compress_blob(sampleinst_raw, "sample+inst bin")
-    comp_size  = len(compressed)
-
-    # Initial BPM / speed
-    speed, tempo = find_initial_bpm_speed(patterns, h.order_list,
+    speed, tempo = find_initial_bpm_speed(pats, virtual_orders,
                                           h.initial_speed, h.initial_tempo)
     tempo = max(25, min(280, tempo))
     bpm_stored = (tempo - 25) & 0xFF
-    vprint(f"  initial speed={speed}, tempo(BPM)={tempo}")
+    vprint(f"  [{song_label}] initial speed={speed}, tempo(BPM)={tempo}")
 
-    # Song offset = header(32) + compressed + song_table(8)
-    song_offset = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY
-    num_taud_pats = P * C
+    # Cue list (source pattern indices) and pos→cue mapping. Skip orders that
+    # already terminate (S3M_ORDER_END) or point past the pattern table.
+    cue_list = []
+    pos_to_cue = {}
+    for pos in positions:
+        order = h.order_list[pos]
+        if order >= S3M_ORDER_END or order >= len(pats):
+            continue
+        pos_to_cue[pos] = len(cue_list)
+        cue_list.append(order)
 
-    sig = (SIGNATURE + b' ' * 14)[:14]
+    # Densely renumber the patterns this song actually emits.
+    used_ordered = []
+    seen = set()
+    for src_pat in cue_list:
+        if src_pat not in seen:
+            used_ordered.append(src_pat)
+            seen.add(src_pat)
+    pat_idx_remap = {src: i for i, src in enumerate(used_ordered)}
+    P_used = len(used_ordered)
 
-    # Pattern bin: for each s3m pattern, for each active channel, 512 bytes
-    vprint("  building pattern bin…")
-    default_pans = [_default_channel_pan(h.channel_settings[ch]) for ch in active_channels]
-    # 1-based inst index → default volume (0..63) for note-trigger vol injection.
-    inst_vols = {
-        i + 1: min(inst.volume, 0x3F)
-        for i, inst in enumerate(instruments)
-        if inst is not None and inst.itype == S3M_TYPE_PCM
-    }
+    C = len(active_channels)
+    if P_used * C > NUM_PATTERNS_MAX:
+        sys.exit(
+            f"error: [{song_label}] {P_used} patterns × {C} channels = "
+            f"{P_used*C} > {NUM_PATTERNS_MAX} Taud pattern limit."
+        )
+
+    # Bxx remap: target source-position → cue-index. Cross-subsong jumps
+    # clamp to cue 0 (loop the subsong rather than jump out of bounds). Walk
+    # only the patterns this song actually emits.
+    crossings = 0
+    for src_pat in used_ordered:
+        if src_pat >= len(pats): continue
+        grid = pats[src_pat]
+        for ch in range(min(32, len(grid))):
+            for row in grid[ch]:
+                if row.effect == EFF_B:
+                    if row.effect_arg in pos_to_cue:
+                        row.effect_arg = pos_to_cue[row.effect_arg] & 0xFF
+                    else:
+                        crossings += 1
+                        row.effect_arg = 0
+    if crossings:
+        vprint(f"  warning: [{song_label}]: {crossings} Bxx target(s) cross "
+               f"subsong boundary; clamped to cue 0")
+
+    # Pattern bin: emit only patterns this song uses (densely indexed).
+    default_pans = [_default_channel_pan(h.channel_settings[ch])
+                    for ch in active_channels]
     pat_bin = bytearray()
-    for pi in range(P):
-        grid = patterns[pi]
+    for src_pat in used_ordered:
+        grid = pats[src_pat]
         for vi, ch in enumerate(active_channels):
-            pat_bin += build_pattern(grid, ch, default_pans[vi], h.linear_slides,
-                                      inst_vols, amiga_mode=not h.linear_slides)
-    assert len(pat_bin) == num_taud_pats * PATTERN_BYTES
+            pat_bin += build_pattern(grid, ch, default_pans[vi],
+                                      h.linear_slides, inst_vols,
+                                      amiga_mode=not h.linear_slides)
 
-    # Rescale TOP_O sample-offset args if samples were globally downsampled.
     pat_bin = rescale_offset_effects(bytes(pat_bin), sample_ratio)
-
-    # Deduplicate identical patterns
-    vprint("  deduplicating patterns…")
-    orig_count = num_taud_pats
+    orig_count = P_used * C
     pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(pat_bin, orig_count)
-    vprint(f"  patterns: {orig_count} → {num_taud_pats} unique ({orig_count - num_taud_pats} deduplicated)")
+    vprint(f"  [{song_label}] patterns: {orig_count} → {num_taud_pats} unique "
+           f"({orig_count - num_taud_pats} deduplicated)")
 
-    # Cue sheet (using remapped pattern indices)
-    vprint("  building cue sheet…")
-    cue_sheet = build_cue_sheet(h.order_list, P, C, pat_remap)
-    assert len(cue_sheet) == NUM_CUES * CUE_SIZE
+    # Cue sheet
+    sheet = bytearray(NUM_CUES * CUE_SIZE)
+    for c in range(NUM_CUES):
+        sheet[c*CUE_SIZE:c*CUE_SIZE+CUE_SIZE] = encode_cue([], 0)
 
-    # Compress pattern bin and cue sheet (per Taud spec)
-    pat_comp = compress_blob(bytes(pat_bin),   "pattern bin")
-    cue_comp = compress_blob(bytes(cue_sheet), "cue sheet")
+    last_active = -1
+    for cue_idx, src_pat in enumerate(cue_list):
+        if cue_idx >= NUM_CUES: break
+        new_pat_idx = pat_idx_remap[src_pat]
+        orig_pats = [new_pat_idx * C + v for v in range(C)]
+        sheet[cue_idx*CUE_SIZE:(cue_idx+1)*CUE_SIZE] = encode_cue(
+            [pat_remap[p] for p in orig_pats], 0)
+        last_active = cue_idx
+
+    if last_active >= 0:
+        sheet[last_active * CUE_SIZE + 30] = 0x01
+    else:
+        sheet[30] = 0x01
+
+    pat_comp = compress_blob(bytes(pat_bin), f"[{song_label}] pattern bin")
+    cue_comp = compress_blob(bytes(sheet),   f"[{song_label}] cue sheet")
 
-    # Song table row (32 bytes; see encode_song_entry).
-    # flags byte: bits 0-1 (ff) = tone mode. ff=1 (Amiga period slides) when S3M's
-    # linear_slides flag is clear; ff=0 otherwise. Pan law is fixed engine-wide to
-    # the equal-energy — no `p` bit any more. Bit 2 reserved (was 'm' fadeout-zero
-    # policy; removed). S3M has no instrument-level fadeout, so every Taud instrument
-    # carries fadeout=0 ("no fade") — notes retire on sample-end or pattern note-cut
-    # effects (SCx) instead, which matches ST3 semantics.
     flags_byte = (0x00 if h.linear_slides else 0x01)
-    song_table = encode_song_entry(
-        song_offset=song_offset,
+    entry_kwargs = dict(
         num_voices=C,
         num_patterns=num_taud_pats,
         bpm_stored=bpm_stored,
@@ -831,36 +881,108 @@ def assemble_taud(h: S3MHeader, instruments: list, patterns: list,
         global_vol=0xFF,
         mixing_vol=180,
     )
-    assert len(song_table) == TAUD_SONG_ENTRY
+    return pat_comp, cue_comp, entry_kwargs
 
-    # Project Data (optional). S3M instruments and samples share the same slot
-    # space, so the names go into both INam and SNam (1-based; slot 0 empty).
+
+def assemble_taud(h: S3MHeader, instruments: list, patterns: list,
+                  with_project_data: bool = True) -> bytes:
+    # Determine active channels (bit7 clear = enabled)
+    active_channels = [i for i, cs in enumerate(h.channel_settings)
+                       if i < 32 and not (cs & 0x80)][:NUM_VOICES]
+    C = len(active_channels)
+    P = len(patterns)
+    vprint(f"  channels: {C}, s3m patterns: {P}")
+
+    # Build sample+instrument bin (shared across subsongs)
+    vprint("  building sample/instrument bin…")
+    sampleinst_raw, _offsets, sample_ratio = build_sample_inst_bin(instruments)
+    assert len(sampleinst_raw) == SAMPLEINST_SIZE
+    compressed = compress_blob(sampleinst_raw, "sample+inst bin")
+    comp_size  = len(compressed)
+
+    # 1-based inst index → default volume (0..63) for note-trigger vol injection.
+    inst_vols = {
+        i + 1: min(inst.volume, 0x3F)
+        for i, inst in enumerate(instruments)
+        if inst is not None and inst.itype == S3M_TYPE_PCM
+    }
+
+    # ── Detect subsongs ──────────────────────────────────────────────────────
+    subsongs = detect_subsongs(h.order_list, _per_pattern_bxx_s3m(patterns),
+                               terminators=(S3M_ORDER_END,),
+                               skip_marker=S3M_ORDER_SKIP)
+    if not subsongs:
+        vprint("  warning: no traversable orders in source; emitting empty song")
+        subsongs = [{'entry': 0, 'positions': []}]
+    n_songs = len(subsongs)
+    if n_songs == 1:
+        vprint(f"  detected 1 song ({len(subsongs[0]['positions'])} orders)")
+    else:
+        vprint(f"  detected {n_songs} subsongs:")
+        for i, ss in enumerate(subsongs):
+            vprint(f"    song {i}: entry@{ss['entry']}, {len(ss['positions'])} orders")
+
+    # ── Build per-song payloads ──────────────────────────────────────────────
+    song_payloads = []
+    for i, ss in enumerate(subsongs):
+        label = f"song {i}" if n_songs > 1 else "song"
+        song_payloads.append(_build_song_payload_s3m(
+            h, patterns, ss['positions'], sample_ratio, inst_vols,
+            active_channels, song_label=label))
+
+    # ── Layout offsets and song table ────────────────────────────────────────
+    song_table_off = TAUD_HEADER_SIZE + comp_size
+    first_song_off = song_table_off + TAUD_SONG_ENTRY * n_songs
+
+    song_table = bytearray()
+    cur_off = first_song_off
+    for pat_comp, cue_comp, entry_kwargs in song_payloads:
+        entry = encode_song_entry(song_offset=cur_off, **entry_kwargs)
+        assert len(entry) == TAUD_SONG_ENTRY
+        song_table += entry
+        cur_off += len(pat_comp) + len(cue_comp)
+
+    # ── Project Data (optional) ──────────────────────────────────────────────
+    # S3M instruments and samples share the same slot space, but carry two
+    # distinct name fields: the 28-byte title (inst.name → INam) and the
+    # 12-byte DOS filename (inst.filename → SNam). e.g. WHEN.s3m instrument #1
+    # is titled "(c) Purple Motion / 1994" with sample name 'HIT1'.
     proj_data = b''
     proj_off  = 0
     if with_project_data:
-        names = [''] + [(inst.name if inst is not None else '')
-                        for inst in instruments[:255]]
+        inst_names   = [''] + [(inst.name     if inst is not None else '')
+                               for inst in instruments[:255]]
+        sample_names = [''] + [(inst.filename if inst is not None else '')
+                               for inst in instruments[:255]]
         proj_data = build_project_data(
             project_name=h.title,
-            instrument_names=names,
-            sample_names=names,
+            instrument_names=inst_names,
+            sample_names=sample_names,
         )
         if proj_data:
-            proj_off = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY \
-                       + len(pat_comp) + len(cue_comp)
+            proj_off = cur_off
             vprint(f"  project data: {len(proj_data)} bytes @ offset {proj_off}")
 
-    # Header (32 bytes): magic(8)+ver(1)+numSongs(1)+compSize(4)+projOff(4)+sig(14)
+    # ── Header ───────────────────────────────────────────────────────────────
+    sig = (SIGNATURE + b' ' * 14)[:14]
     header = (
         TAUD_MAGIC +
-        bytes([TAUD_VERSION, 1]) +
+        bytes([TAUD_VERSION, n_songs & 0xFF]) +
         struct.pack('<I', comp_size) +
         struct.pack('<I', proj_off) +
         sig
     )
     assert len(header) == TAUD_HEADER_SIZE
 
-    return header + compressed + song_table + pat_comp + cue_comp + proj_data
+    out = bytearray()
+    out += header
+    out += compressed
+    out += song_table
+    for pat_comp, cue_comp, _ in song_payloads:
+        out += pat_comp
+        out += cue_comp
+    out += proj_data
+    return bytes(out)
 
 
 # ── Main ─────────────────────────────────────────────────────────────────────

taud_common.py

@@ -96,9 +96,9 @@ NUM_VOICES       = 20
 SAMPLE_LEN_LIMIT = 65535
 
 # Note word sentinels
-NOTE_NOP    = 0xFFFF
-NOTE_KEYOFF = 0x0000
-NOTE_CUT    = 0xFFFE
+NOTE_NOP    = 0x0000
+NOTE_KEYOFF = 0x0001
+NOTE_CUT    = 0x0002
 TAUD_C4     = 0x5000   # The audio engine's Middle C
 
 # Cue sheet instruction byte (cue offset 30; offset 31 = arg byte for 2-byte forms).
@@ -411,6 +411,117 @@ def encode_song_entry(song_offset: int, num_voices: int, num_patterns: int,
     return entry
 
 
+# ── Subsong detection (multi-song .taud emission) ────────────────────────────
+#
+# Modules and trackers don't natively carry a subsong table; subsongs emerge
+# from the order-list flow graph. OpenMPT-style: take the lowest unvisited
+# non-terminator order as the next subsong entry, do forward reachability via
+# fall-through (oi→oi+1) plus pattern-Bxx targets, mark all reached orders
+# visited, repeat until no entries remain.
+#
+# Fall-through is treated as dead when the pattern at oi has a Bxx on its
+# absolute last row — the convention every tracker uses for "song ends here,
+# loop back" — which lets non-looping subsongs separated by Bxx-terminated
+# predecessors be detected even without an explicit 0xFF marker.
+#
+# WHEN.s3m → 4 subsongs (0xFF separators); Insaniq2.it → 8 subsongs (Bxx-row-63
+# terminators, no 0xFF separators). Single-song files collapse to 1 subsong.
+
+def detect_subsongs(orders, pattern_bxx_fn, *,
+                    terminators=(0xFF,), skip_marker=0xFE):
+    """Detect subsongs by repeated forward reachability.
+
+    Args:
+        orders: list of raw order bytes from the source file. Each element is
+            either a pattern index (0..n-1), a skip value (transparently
+            skipped), or a terminator value (ends a path).
+        pattern_bxx_fn: callable(pattern_idx) → (set_of_bxx_target_order_indices,
+            kills_fallthrough). `kills_fallthrough` is True when the pattern's
+            last row carries a Bxx (unconditional terminator); when False,
+            fall-through to oi+1 is kept as a graph edge.
+        terminators: int, or iterable of ints. Order values that end a path
+            (default 0xFF). Pass an empty iterable for formats without a
+            terminator marker (XM).
+        skip_marker: int, or iterable of ints. Order values that are
+            transparently passed during traversal (default 0xFE). XM passes
+            `range(pattern_count, 256)` to skip out-of-range pattern refs.
+
+    Returns:
+        List of subsongs in entry-order. Each subsong is a dict:
+            'entry': original order-list position of the entry (int)
+            'positions': list of original order-list positions belonging to this
+                subsong, in cue-sheet order (entry first, then ascending index
+                wrap-around). Each position's pattern index = orders[pos].
+        For a single-song file the result has one element whose 'positions'
+        covers the whole order list (minus terminators/skips). For files where
+        every order is a terminator/skip, the result is empty.
+    """
+    n = len(orders)
+    term = {terminators} if isinstance(terminators, int) else set(terminators)
+    skips = ({skip_marker} if isinstance(skip_marker, int)
+             else set(skip_marker))
+
+    def _is_traversable(pos: int) -> bool:
+        if pos < 0 or pos >= n:
+            return False
+        v = orders[pos]
+        return v not in term and v not in skips
+
+    visited = set()
+    songs = []
+
+    while True:
+        # Lowest unvisited traversable position = next subsong entry.
+        entry = next((i for i in range(n)
+                      if i not in visited and _is_traversable(i)), None)
+        if entry is None:
+            break
+
+        # Reachability claims orders for this subsong, stopping at orders
+        # already owned by a previous subsong.
+        owned = set()
+        stack = [entry]
+        while stack:
+            oi = stack.pop()
+            if oi in owned or oi in visited:
+                continue
+            if oi < 0 or oi >= n:
+                continue
+            v = orders[oi]
+            if v in term:
+                continue
+            if v in skips:
+                if oi + 1 < n:
+                    stack.append(oi + 1)
+                continue
+            owned.add(oi)
+            tgts, kills = pattern_bxx_fn(v)
+            for t in tgts:
+                if 0 <= t < n:
+                    stack.append(t)
+            if not kills and oi + 1 < n:
+                stack.append(oi + 1)
+
+        if not owned:
+            # Avoid infinite loop on a degenerate entry (shouldn't happen
+            # since _is_traversable already filtered terminators / skips).
+            visited.add(entry)
+            continue
+        visited |= owned
+
+        # Cue-sheet order: ascending index, rotated so entry comes first.
+        # The natural order-list traversal is sequential, so increasing index
+        # matches the play sequence when fall-through is alive; rotation
+        # ensures cue 0 is the entry order.
+        sorted_owned = sorted(owned)
+        rot = sorted_owned.index(entry)
+        positions = sorted_owned[rot:] + sorted_owned[:rot]
+
+        songs.append({'entry': entry, 'positions': positions})
+
+    return songs
+
+
 # ── Project Data section (terranmon.txt:2601+) ───────────────────────────────
 
 PROJECT_DATA_MAGIC = bytes([0x1E, 0x54, 0x61, 0x75, 0x64, 0x50, 0x72, 0x4A])  # \x1ETaudPrJ
@@ -432,13 +543,93 @@ def _name_table_blob(names) -> bytes:
     return b'\x1E'.join((n or '').encode('utf-8', 'replace') for n in names[:end])
 
 
+# ── Ixmp encoder (terranmon.txt §Project Data → Ixmp) ───────────────────────
+
+# Per-patch byte layout. Field offsets must match AudioJSR223Delegate.uploadInstrumentPatches
+# (Kotlin parser) and terranmon.txt "Ixmp. Instrument extra samples".
+IXMP_PATCH_SIZE     = 31
+IXMP_PAN_NO_OVERRIDE = 0xFF
+IXMP_DNV_NO_OVERRIDE = 0
+IXMP_VIBWAVE_NO_OVERRIDE = 0xFF
+
+
+def encode_ixmp_patch(p: dict) -> bytes:
+    """Encode a single patch dict into 31 bytes.
+
+    Expected keys (numeric values; defaults are applied for missing optional fields):
+        pitch_start, pitch_end        : Taud 4096-TET noteVal (Uint16)
+        volume_start, volume_end      : 0..63 (Uint8)
+        sample_ptr                    : Uint32 (sample bin offset)
+        sample_length                 : Uint16
+        play_start, loop_start, loop_end : Uint16
+        sampling_rate                 : Uint16 (same encoding as base inst byte 6-7)
+        sample_detune                 : Int16, signed 4096-TET (default 0)
+        loop_mode                     : Uint8 (default 0)
+        default_pan                   : Uint8, 0xFF = no override (default 0xFF)
+        default_note_volume           : Uint8 IT-scaled (0 = no override, default 0)
+        vibrato_speed/sweep/depth/rate: Uint8 (default 0)
+        vibrato_waveform              : Uint8 (0..7 or 0xFF for no override, default 0xFF)
+    """
+    pitch_start = max(0, min(0xFFFF, int(p['pitch_start'])))
+    pitch_end   = max(0, min(0xFFFF, int(p['pitch_end'])))
+    vol_start   = max(0, min(63,     int(p.get('volume_start', 0))))
+    vol_end     = max(0, min(63,     int(p.get('volume_end', 63))))
+    sample_ptr  = int(p['sample_ptr']) & 0xFFFFFFFF
+    sample_len  = max(0, min(0xFFFF, int(p['sample_length'])))
+    play_start  = max(0, min(0xFFFF, int(p.get('play_start', 0))))
+    loop_start  = max(0, min(0xFFFF, int(p.get('loop_start', 0))))
+    loop_end    = max(0, min(0xFFFF, int(p.get('loop_end',   0))))
+    rate        = max(0, min(0xFFFF, int(p.get('sampling_rate', 0))))
+    detune      = max(-0x8000, min(0x7FFF, int(p.get('sample_detune', 0))))
+    return struct.pack(
+        '<BHHBBIHHHHHhBBBBBBBB',
+        1,                                       # patch version
+        pitch_start, pitch_end,
+        vol_start,   vol_end,
+        sample_ptr,
+        sample_len,
+        play_start, loop_start, loop_end,
+        rate,
+        detune,
+        int(p.get('loop_mode', 0))            & 0x07,
+        int(p.get('default_pan', IXMP_PAN_NO_OVERRIDE))     & 0xFF,
+        int(p.get('default_note_volume', IXMP_DNV_NO_OVERRIDE)) & 0xFF,
+        int(p.get('vibrato_speed', 0))        & 0xFF,
+        int(p.get('vibrato_sweep', 0))        & 0xFF,
+        int(p.get('vibrato_depth', 0))        & 0xFF,
+        int(p.get('vibrato_rate',  0))        & 0xFF,
+        int(p.get('vibrato_waveform', IXMP_VIBWAVE_NO_OVERRIDE)) & 0xFF,
+    )
+
+
+def encode_ixmp_payload(patches_by_inst: dict) -> bytes:
+    """Encode a dict {instrument_id: [patch_dict, ...]} as one Ixmp section payload
+    (the body that follows the FourCC + length header). Instruments are written in
+    ascending id order. Overlapping pitch+volume rectangles within one instrument
+    are INVALID per spec and the caller is responsible for keeping them disjoint."""
+    if not patches_by_inst:
+        return b''
+    out = bytearray()
+    for inst_id in sorted(patches_by_inst):
+        patches = patches_by_inst[inst_id]
+        if not patches:
+            continue
+        out.append(int(inst_id) & 0xFF)
+        cnt = len(patches)
+        out += bytes([cnt & 0xFF, (cnt >> 8) & 0xFF, (cnt >> 16) & 0xFF])  # Uint24 LE
+        for patch in patches:
+            out += encode_ixmp_patch(patch)
+    return bytes(out)
+
+
 def build_project_data(*, project_name: str = '',
                        author: str = '',
                        copyright_str: str = '',
                        sample_names=None,
                        instrument_names=None,
                        pattern_names=None,
-                       song_metadata=None) -> bytes:
+                       song_metadata=None,
+                       ixmp_patches=None) -> bytes:
     """Build the optional PROJECT DATA section payload.
 
     Returns the full block (8-byte magic + 8 reserved bytes + concatenated
@@ -493,6 +684,9 @@ def build_project_data(*, project_name: str = '',
             smet += payload
         add(b'sMet', bytes(smet))
 
+    if ixmp_patches:
+        add(b'Ixmp', encode_ixmp_payload(ixmp_patches))
+
     if not sections:
         return b''
 
@@ -503,31 +697,44 @@ def build_project_data(*, project_name: str = '',
 
 def normalise_sample(raw: bytes, signed: bool, is_16bit: bool,
                      is_stereo: bool, name: str) -> bytes:
-    """Return unsigned 8-bit mono sample bytes, downmixing/depthing as needed."""
+    """Return unsigned 8-bit mono sample bytes, downmixing/depthing as needed.
+
+    Stereo samples are stored as a split (non-interleaved) layout — the full
+    left channel block followed by the full right channel block — matching the
+    on-disk format used by IT, S3M, and XM (Schism's SF_SS).
+    """
     out = []
-    stride = (2 if is_16bit else 1) * (2 if is_stereo else 1)
-    i = 0
-    while i + stride <= len(raw):
+    bps     = 2 if is_16bit else 1
+    chans   = 2 if is_stereo else 1
+    n_frames = len(raw) // (bps * chans)
+    chan_bytes = n_frames * bps
+
+    for i in range(n_frames):
         if is_16bit:
             if is_stereo:
-                l16 = struct.unpack_from('<h', raw, i)[0]
-                r16 = struct.unpack_from('<h', raw, i+2)[0]
+                l16 = struct.unpack_from('<h', raw, i*2)[0]
+                r16 = struct.unpack_from('<h', raw, chan_bytes + i*2)[0]
                 s = (l16 + r16) >> 1
             else:
-                s = struct.unpack_from('<h', raw, i)[0]
+                s = struct.unpack_from('<h', raw, i*2)[0]
             v = (s >> 8) + 128
         else:
             if is_stereo:
-                l8 = raw[i]; r8 = raw[i+1]
-                raw_s = (l8 + r8) // 2
+                l8 = raw[i]
+                r8 = raw[chan_bytes + i]
+                if signed:
+                    l_s = l8 - 256 if l8 >= 0x80 else l8
+                    r_s = r8 - 256 if r8 >= 0x80 else r8
+                    v = ((l_s + r_s) >> 1) + 128
+                else:
+                    v = (l8 + r8) >> 1
             else:
                 raw_s = raw[i]
-            if signed:
-                v = (raw_s ^ 0x80) & 0xFF
-            else:
-                v = raw_s
+                if signed:
+                    v = (raw_s ^ 0x80) & 0xFF
+                else:
+                    v = raw_s
         out.append(v & 0xFF)
-        i += stride
     if is_16bit or is_stereo:
         vprint(f"  info: '{name}' converted to unsigned 8-bit mono ({len(out)} samples)")
     return bytes(out)

terranmon.txt

@@ -49,7 +49,13 @@ MMIO
 0..31 RO: Raw Keyboard Buffer read. Won't shift the key buffer
 32..33 RO: Mouse X pos
 34..35 RO: Mouse Y pos
-36 RO: Mouse down? (1 for TRUE, 0 for FALSE)
+36 RO: Mouse down?
+    bit 0: left
+    bit 1: right
+    bit 2: middle
+
+    bit 6: wheel up
+    bit 7: wheel down
 37 RW: Read/Write single key input. Key buffer will be shifted. Manual writing is
     usually unnecessary as such action must be automatically managed via LibGDX
     input processing.
@@ -2144,8 +2150,9 @@ from source.
         * Continuous multiplier applied on every output sample (matches IT's
           `chan->instrument_volume`, see Schism player/csndfile.c:1317 and
           player/sndmix.c:1171). Independent of the volume column / Mxx /
-          Nxx — those operate on rowVolume/channelVolume, while IGV scales
-          the final mix unconditionally.
+          Nxx — the volume column writes the per-note axis (noteVolume),
+          Mxx/Nxx write the per-channel axis (channelVolume); IGV scales
+          the final mix unconditionally and is orthogonal to both.
         * ImpulseTracker has separate `inst.gv` (0..128) and samplewise
           `sample.gv` (0..64). Since Taud has no samplewise record, fold
           the two factors into a single 0..255 value:
@@ -2254,7 +2261,7 @@ from source.
         * Semantics (matches IT/Schism player/effects.c:1664-1764 csf_check_nna):
             - Fires on every fresh foreground note trigger on a channel, BEFORE the
               NNA-spawn step that would ghost the existing voice. Does NOT fire on
-              tone portamento, on note-off (0x0000), on note-cut (0xFFFE), or on
+              tone portamento, on note-off (0x0001), on note-cut (0x0002), or on
               empty cells.
             - The DCT/DCA values consulted belong to the EXISTING voice's instrument
               (i.e. the OLD note's instrument, not the incoming note's). Different
@@ -2282,15 +2289,17 @@ from source.
               spawns inherits that DCA-modified state (e.g. noteFading carries over).
             - The new note then triggers normally on the foreground channel.
 196 Uint8  Default Note Volume (0..255)
-        * Per-trigger default for `channelVolume` / `rowVolume` when the row
-          carries a fresh note + instrument byte but no explicit volume column
-          (matches IT's `chan->volume = psmp->volume` on note-on, Schism
+        * Per-trigger default for the per-note volume axis (`noteVolume` in
+          the engine, analog of IT's `chan->volume`) when the row carries a
+          fresh note + instrument byte but no explicit volume column (matches
+          IT's `chan->volume = psmp->volume` on note-on, Schism
           player/effects.c:1302 and :1432). The 8-bit value rescales to
-          Taud's 0..63 row volume range:
-              row_default = round(default_note_volume * 63 / 255)
-          Any explicit V column on the trigger row OVERRIDES this — i.e.
-          rowVolume = vol_value, exactly mirroring IT's "V column replaces
-          chan->volume" rule.
+          Taud's 0..63 note-volume range:
+              note_default = round(default_note_volume * 63 / 255)
+          Any explicit V column SET on the trigger row OVERRIDES this — i.e.
+          noteVolume = vol_value, exactly mirroring IT's "V column replaces
+          chan->volume" rule. The per-channel axis (`channelVolume`, set by
+          Mxx / Nxx) is independent and is NOT reset on re-trigger.
         * Source-format mapping:
             - IT:  taud_dnv = round(sample.vol * 255 / 64)        # 0..64 → 0..255
             - XM:  taud_dnv = round(sample.volume * 255 / 64)     # 0..64 → 0..255
@@ -2396,6 +2405,14 @@ TODO:
         previous "row volume default = 63" behaviour.
     [x] physical_presence order 0x1F chn 2: note cuts unexpectedly fast — engine fix
     [x] GSLINGER order 0x03 chn 1: L 0100 fades unexpectedly fast? — converter fix
+    [x] do not reset tickspeed on pattern view play / add key to modify tick speed ('[' down/']' up)
+    [x] expose song table on UI (test with `insaniq2.taud`)
+    [x] 0x0000 - no-op; 0x0001 - key-off; 0x0002 - note-cut 0x0010..0x001F - INT0..INTF
+        [ ] establish hooks for the interrupts
+    [x] Samples and Instruments view (viewer on taut.js; editor on separate .js)
+        follow the ImpulseTracker design first, then improve from there
+    [?] Sample desig for instrument in Pitch-Volume space (one rectangle = one patch). If undefined, the old sample pointer falls thru
+        [ ] Needs .it and .xm test file to complete it2taud and xm2taud
 
 TODO - list of demo songs that MUST ship with Microtone:
     * 4THSYM (rename to Fourth Symmetriad) — excellent piece for demonstrating NNAs and filter envelopes
@@ -2416,13 +2433,14 @@ Play Data: play data are series of tracker-like instructions, visualised as:
 rr||NOTE|Ins|E.Vol|E.Pan|EE.ff|
 63||FFFF|255|3 63|3 63|FF FFFF| (8 bytes per line, 512 bytes per pattern, 128 patterns on 64 kB bank, 32 banks available (pattern 0xFFF -- bank 31, pattern 127 is a sentinel value for no-pattern))
 
-notes are tuned as 4096 Tone-Equal Temperament. Tuning is set per-sample using their Sampling rate value.
+notes are tuned as 4096 Tone-Equal Temperament. Tuning is set per-sample using their Sampling rate value. 0x1000: C at zeroth octave; 0xF000: C at 14th octave; 0xFFFF: ~C at 15th octave; 0x0000..0x001F: reserved for sentinels (valid playable note range is 0x0020..0xFFFF)
 
 Special values:
 
-note 0xFFFF: no-op
-note 0xFFFE: note cut
-note 0x0000: key-off
+note 0x0000: no-op
+note 0x0001: key-off
+note 0x0002: note cut
+note 0x0010..0x001F: Interrupt 0..F (notation: Int0..IntF) — reserved interrupt slots; engine has no default handler.
 
 inst 0: no instrument change
 
@@ -2453,7 +2471,7 @@ Audio Adapter MMIO
     Write 16 to initialise the MP2 context (call this before the decoding of NEW music)
     Write 1 to decode the frame as MP2
 
-    Calling with more than one bit set will result in UNDEFINED BEHAVIOUR
+    Calling with more than one bit set will result in UNDEFINED BEHAVIOUR — except for the flag 0x11, in which the hardware must initialise then immediately start decoding.
 
 41 RO: MP2 Decoder Status
     Non-zero value indicates the decoder is busy. Different value may indicate different decoder status.
@@ -2470,6 +2488,11 @@ Audio Adapter MMIO
 2368..4095 RW: MP2 Frame to be decoded
 4096..4097 RO: MP2 Frame guard bytes; always return 0 on read
 
+4098..4353 RW: tracker per-voice fader (0: full volume, 255: full silence) for playhead #0
+4354..4609 RW: tracker per-voice fader (0: full volume, 255: full silence) for playhead #1
+4610..4865 RW: tracker per-voice fader (0: full volume, 255: full silence) for playhead #2
+4866..5121 RW: tracker per-voice fader (0: full volume, 255: full silence) for playhead #3
+
 Sound Hardware Info
     - Sampling rate: 32000 Hz
     - Bit depth: 8 bits/sample, unsigned
@@ -2598,6 +2621,17 @@ This is a file format for Taud tracker data. Taud can be extended with Microtone
 
 Endianness: Little
 
+# Conformance language
+(RFC 2119+8174)
+- **MUST** / **MUST NOT** / **REQUIRED** / **SHALL** / **SHALL NOT** — absolute requirements / prohibitions. A conforming implementation **SHALL** observe every such rule; an implementation that violates one is non-conforming.
+- **SHOULD** / **SHOULD NOT** / **RECOMMENDED** / **NOT RECOMMENDED** — strong guidance. An implementation **MAY** deviate in particular circumstances, but the full implications **MUST** be understood and weighed before doing so.
+- **MAY** / **OPTIONAL** — truly optional. Implementations that include the feature and implementations that omit it are equally conforming, and each **MUST** be prepared to interoperate with the other (with reduced functionality where the optional feature is the means of interoperation).
+(IMPLEMENTATION DETAILS)
+- **INVALID.** Blame the encoder; decoder MUST stop decoding with appropriate errors.
+- **UNDEFINED BEHAVIOUR.** Encoder MAY encode it; decoder MAY do whatever it wants to, including spawning a daemon out of your nose.
+- **IGNORED.** Encoder MAY encode it; decoder MUST skip past it.
+- **RESERVED.** Encoder MUST NOT encode it. Decoder MUST skip past it.
+
 # File Structure
 \x1F T S V M a u d
 [HEADER]
@@ -2634,15 +2668,16 @@ Endianness: Little
     Uint16  Current Tuning base note (1..65533). A4 (western default) is 0x5C00. C9 (tracker default) is 0xA000. If zero, assume the tracker default value
     Float32 Frequency at the base note. Tracker default is 8363.0. If zero, assume the tracker default
     Uint8   Flags for Global Behaviour (effect symbol '1')
-        0b 0000 00ff
-            ff: tone mode          (0: linear pitch slides, 1: Amiga period slides, 2: linear-frequency slides, 3: reserved)
+        0b 000 rrr ff
+            ff: tone mode          (0: linear pitch slides, 1: Amiga period slides, 2: linear-frequency slides, 3: RESERVED)
+            rrr: interpolation mode (0: default, 1: none, 2: Amiga 500, 3: Amiga 1200, 4: SNES 4-tap Gaussian, 5: NES DPCM simulation)
     Uint8   Song global volume
         * ImpulseTracker has range of 0..128; multiply by (255/128) then round to int
     Uint8   Song mixing volume
         * ImpulseTracker has range of 0..128; multiply by (255/128) then round to int
     Uint32  Compressed size of PATTERN BIN for this song
     Uint32  Compressed size of CUE SHEET for this song
-    Byte[6] Reserved
+    Byte[6] RESERVED
 
     Taud device can queue up to 2 "playdata" in its buffer, which can be interpreted as a song.
 
@@ -2664,7 +2699,7 @@ Endianness: Little
 Project Data is just a concatenation of blocks identified by their FourCC.
 
     Byte[8] Magic (\x1E T a u d P r J)
-    Byte[8] Reserved
+    Byte[8] RESERVED
     * Repetition of
     Byte[4] Title of the section (fourcc)
     Uint32  Section length
@@ -2683,6 +2718,7 @@ prefixes:
 * PCom. Project author. Encoding: UTF-8
 * PCpr. Project copyright string. Encoding: UTF-8
 * PNam. Project name. Encoding: UTF-8
+* Pmsg. Project message. Encoding: UTF-8
 
 * INam. Instrument name table. Strings separated by 0x1E
 
@@ -2714,10 +2750,11 @@ prefixes:
     * Repetition of:
     Uint8   Notation index (starting from zero) used by songs
     Uint32  Size of this notation following this field
-    Uint16   Reserved for flags
-    Float32 Interval size (octave system = 2.0f). If you are not using an interval system (which means you are responsible for defining every note expressible), this must be NaN. 0f and Infinity are considered illegal
-    Uint16  Notes between interval MINUS ONE (or octave); 12-TET will have value 11
-    Byte[8] Reserved
+    Uint16  RESERVED for flags
+    Uint16  Interval size in 4096-TET lattice (octave = 0x1000, tritave = 0x195C). If you are not using an interval system (which means you are responsible for defining every note expressible), this must be 0.
+    Uint16  RESERVED for float32 interval size (should it be in 4096-TET which is inexact or frequency multiplier which is exact but difficult to implement?)
+    Uint16  Notes between interval (or octave) MINUS ONE; 12-TET will have value 11
+    Byte[8] RESERVED
     Byte[*]     Name, null terminated. Encoding: UTF-8
     Byte[*]     Notation table. 0xFF-separated and null-terminated. Encoding: Taud charset
     Uint16[*]  Frequency table. Size of the table is defined by "Notes between interval MINUS ONE". This is a lookup table of relative pitch offsets (against the base tuning note) in 4096-TET space. Index zero of this table will be 0x0 if you read the spec right
@@ -2738,6 +2775,45 @@ prefixes:
     Uint8   Version (Ascii 'a')
     Bytes   Notation definitions (see above)
 
+* Ixmp. Instrument extra samples
+    * Repetition of:
+    Uint8   Instrument ID
+    Uint24  Count of patches
+        ** Repetition of:
+        Uint8  Patch definition version (always 1)
+        Uint16 Pitch start                 ; Taud 4096-TET noteVal (same scale as pattern-cell note)
+        Uint16 Pitch end (inclusive)
+        Uint8  Volume start                ; 0..63
+        Uint8  Volume end (inclusive)      ; 0..63
+            - Above four parameters define a rectangle over the Pitch-Volume space. See Notes 4 and 5
+        Uint32 Sample pointer
+        Uint16 Sample length
+        Uint16 Play Start (usually 0 but not always)
+        Uint16 Loop Start (can be smaller than Play Start)
+        Uint16 Loop End
+        Uint16 samplingRate                ; per-sample C-5 speed; same encoding as base instrument byte 6-7
+        Int16  sampleDetune                ; per-sample fine detune in signed 4096-TET units (XM finetune; IT samples leave 0)
+        Uint8  loopMode                    ; same encoding as base instrument byte 14 (bits 0-1 = mode, bit 2 = sustain loop)
+        Uint8  defaultPan                  ; per-sample default pan (0..255; 0x80 = centre); 0xFF = "no override"
+        Uint8  defaultNoteVolume           ; per-sample default note volume (0..255 scaled from IT 0..64); 0 = "no override"
+        Uint8  vibratoSpeed                ; per-sample auto-vibrato (mirrors base inst byte 175)
+        Uint8  vibratoSweep                ; per-sample auto-vibrato (mirrors base inst byte 176)
+        Uint8  vibratoDepth                ; per-sample auto-vibrato (mirrors base inst byte 187)
+        Uint8  vibratoRate                 ; per-sample auto-vibrato (mirrors base inst byte 188)
+        Uint8  vibratoWaveform             ; bits 0-2 only (mirrors instrumentFlag bits 2-4); 0xFF = "no override"
+
+    Notes:
+    0. this extension is made to support IT/XM instrument spec as well as partial compatibility to SF2 (Soundfont format two)
+    1. Envelopes (vol/pan/pf), fadeout, NNA / DCT / DCA, pitch-pan, filter, IGV and any other "instrument-scope" parameters all follow the base instrument definition. Only sample-scope parameters (the patch fields listed above) override.
+    2. overlapping regions are considered INVALID
+    3. multiple Ixmp blocks pointing the same instrument are considered INVALID
+    4. IT and XM does not define volumes. Keep the Volume rectangle at 0..63 — the engine clamps to that range when matching.
+    5. SF2 does define volumes (because MIDI). Convert it using `round(velocity * (63/127))`
+        On import, `initialAttenuation`, filters and ADSR shall be ignored
+    6. Patch selection at trigger time walks the patch list in order; the first patch whose rectangle contains the trigger's (noteVal, rowVolume) wins. When no patch matches, the base instrument's sample fields are used unchanged.
+    7. Sentinel values listed above ("no override") let a patch defer to the base instrument for a given field — used by converters that don't carry per-sample data for one of the dimensions (e.g. SF2 ignoring per-sample pan).
+    8. Total per-patch payload is 31 bytes.
+
 --------------------------------------------------------------------------------
 
 **S3M (ScreamTracker 3) to Taud conversion notes**

tsvm_core/src/net/torvald/tsvm/AudioJSR223Delegate.kt

@@ -23,7 +23,9 @@ import net.torvald.tsvm.peripheral.MP2Env
  * 8. Call `setCuePosition(playhead, 0)` then `play(playhead)`.
  *
  * Note values: 0x4000 = C3 (sample's native pitch), 4096 steps per octave.
- * Empty row: note = 0xFFFF (no trigger). All 256 instrument slots (0-255) are valid.
+ * Empty row: note = 0x0000 (no trigger). Note sentinels (0x0000..0x001F): 0x0000 = no-op,
+ * 0x0001 = key-off, 0x0002 = note cut, 0x0010..0x001F = Int0..IntF (reserved interrupts).
+ * Valid playable notes are 0x0020..0xFFFF. All 256 instrument slots (0-255) are valid.
  *
  * ## How to upload PCM audio into a playhead
  *
@@ -91,11 +93,157 @@ class AudioJSR223Delegate(private val vm: VM) {
 
     fun getTrackerRow(playhead: Int) = getPlayhead(playhead)?.trackerState?.rowIndex ?: 0
 
+    /** Mute is now a thin wrapper over the per-voice fader: muting writes 255 (silence),
+     *  unmuting clears the fader back to 0 (unity). Callers that want a partial attenuation
+     *  should use setVoiceFader directly. */
     fun setVoiceMute(playhead: Int, voice: Int, muted: Boolean) {
-        getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19))?.muted = muted
+        getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19))?.fader = if (muted) 255 else 0
     }
     fun getVoiceMute(playhead: Int, voice: Int): Boolean =
-        getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19))?.muted ?: false
+        (getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19))?.fader ?: 0) == 255
+
+    /** Externally-controlled per-voice fader. 0 = unity, 255 = silence; values are masked to 8 bits.
+     *  Mirrors MMIO 4098.. (256 bytes per playhead, first 20 entries map to live voice slots). */
+    fun setVoiceFader(playhead: Int, voice: Int, fader: Int) {
+        getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19))?.fader = fader and 255
+    }
+    fun getVoiceFader(playhead: Int, voice: Int): Int =
+        getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19))?.fader ?: 0
+
+    /** Effective per-voice tracker volume (0.0..1.0) — what the mixer applies right now after the
+     *  envelope, fadeout, vol-column / D-slide / tremolo ramp, and the host-owned per-voice fader,
+     *  but BEFORE master/mixing/global volumes. Returns 0.0 for inactive voices. Mirrors the
+     *  perVoiceGain assembled in the per-sample mix loop (AudioAdapter.kt:3201). */
+    fun getVoiceEffectiveVolume(playhead: Int, voice: Int): Double {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 0.0
+        if (!v.active) return 0.0
+        val effEnvVol = if (v.volEnvOn) v.envVolMix else 1.0
+        val faderGain = (255 - v.fader) / 255.0
+        return (effEnvVol * v.fadeoutVolume * v.currentMixVolume * faderGain).coerceIn(0.0, 1.0)
+    }
+
+    /** Effective per-voice tracker pan (0..255, 128 = centre) — channelPan modulated by the pan
+     *  envelope when it is active. Returns 128 (centre) for inactive voices. Mirrors the pan
+     *  selection in the per-sample mix loop (AudioAdapter.kt:3205). */
+    fun getVoiceEffectivePan(playhead: Int, voice: Int): Int {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 128
+        if (!v.active) return 128
+        return if (v.hasPanEnv && v.panEnvOn) {
+            val envPanRaw = (v.envPan * 255.0).toInt().coerceIn(0, 255)
+            (v.channelPan + envPanRaw - 128).coerceIn(0, 255)
+        } else v.channelPan.coerceIn(0, 255)
+    }
+
+    /** Whether the voice slot is currently sounding (i.e. owns an active sample). Mirrors
+     *  `Voice.active` which is the source of truth for "is this voice contributing to the mix
+     *  right now". Visualisers should treat this as the authoritative on/off bit. */
+    fun getVoiceActive(playhead: Int, voice: Int): Boolean =
+        getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19))?.active == true
+
+    /** Active-note counts per instrument id (index 0..255): how many notes are sounding *right
+     *  now* for each instrument, counting ~~BOTH~~ the live foreground voices ~~and the NNA background
+     *  ghosts in the mixer-private pool~~~. Lets visualisers colour by polyphony. The ghost pool is
+     *  mutated by the render thread, so it is read defensively by index and any transient
+     *  inconsistency is tolerated (a single best-effort frame). */
+    fun getActiveNoteCounts(playhead: Int): IntArray {
+        val counts = IntArray(256)
+        val ts = getPlayhead(playhead)?.trackerState ?: return counts
+        for (v in ts.voices) {
+            if (v.active) counts[v.instrumentId and 0xFF]++
+        }
+        // disabling NNA for now
+        /*try {
+            val bg = ts.backgroundVoices
+            for (i in 0 until bg.size) {
+                val v = bg.getOrNull(i) ?: continue
+                if (v.active) counts[v.instrumentId and 0xFF]++
+            }
+        } catch (_: Exception) { /* ghost pool mutated mid-read — counts are best-effort */ }
+        */
+        return counts
+    }
+
+    /** Funk-repeat (S$Fx) speed currently driving the voice: 0 = off, otherwise the per-tick
+     *  accumulator increment. A non-zero value on an active voice means the voice is live-inverting
+     *  its instrument's loop region right now — visualisers can use this to gate the funk overlay. */
+    fun getVoiceFunkSpeed(playhead: Int, voice: Int): Int {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 0
+        if (!v.active) return 0
+        return v.funkSpeed
+    }
+
+    /** Snapshot of an instrument's funk-repeat XOR mask (one bit per loop-region byte; a set bit
+     *  flips that byte by 0xFF during playback). Returns the mask bytes as ints (0..255), or an
+     *  empty array when the instrument has never been funk-repeated. The render thread mutates the
+     *  live mask, so this returns a copy — the caller gets a stable single-frame view. */
+    fun getInstrumentFunkMask(slot: Int): IntArray {
+        val mask = getFirstSnd()?.instruments?.get(slot and 0xFF)?.funkMask ?: return IntArray(0)
+        return IntArray(mask.size) { mask[it].toInt() and 0xFF }
+    }
+
+    /** Live noteVal (0..65535, 4096-TET) of the foreground voice — the value the mixer is using
+     *  *right now* including any in-flight vibrato / arpeggio / portamento delta. Returns 0 for
+     *  inactive voices. */
+    fun getVoiceNote(playhead: Int, voice: Int): Int {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 0
+        if (!v.active) return 0
+        return v.noteVal and 0xFFFF
+    }
+
+    /** Instrument id (0..255) currently bound to the voice slot, or 0 if the voice is inactive. */
+    fun getVoiceInstrument(playhead: Int, voice: Int): Int {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 0
+        if (!v.active) return 0
+        return v.instrumentId and 0xFF
+    }
+
+    /** Current sample-frame playback position (fractional double) of the voice. Returns -1.0
+     *  when the voice is inactive so visualisers can distinguish "no cursor" from "cursor at 0". */
+    fun getVoiceSamplePos(playhead: Int, voice: Int): Double {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return -1.0
+        if (!v.active) return -1.0
+        return v.samplePos
+    }
+
+    /** Volume-envelope segment index — i.e. the node the voice is currently moving *away* from
+     *  (the next node it will hit is index + 1). Returns -1 when inactive. */
+    fun getVoiceEnvVolIndex(playhead: Int, voice: Int): Int {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return -1
+        if (!v.active) return -1
+        return v.envIndex
+    }
+    /** Seconds elapsed *into* the current volume-envelope segment (0 ≤ t < segment.offset). */
+    fun getVoiceEnvVolTime(playhead: Int, voice: Int): Double {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 0.0
+        if (!v.active) return 0.0
+        return v.envTimeSec
+    }
+
+    /** Pan-envelope segment index — see [getVoiceEnvVolIndex]. */
+    fun getVoiceEnvPanIndex(playhead: Int, voice: Int): Int {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return -1
+        if (!v.active) return -1
+        return v.envPanIndex
+    }
+    /** Seconds elapsed into the current pan-envelope segment. */
+    fun getVoiceEnvPanTime(playhead: Int, voice: Int): Double {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 0.0
+        if (!v.active) return 0.0
+        return v.envPanTimeSec
+    }
+
+    /** Pitch/filter-envelope segment index — see [getVoiceEnvVolIndex]. */
+    fun getVoiceEnvPitchIndex(playhead: Int, voice: Int): Int {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return -1
+        if (!v.active) return -1
+        return v.envPfIndex
+    }
+    /** Seconds elapsed into the current pitch/filter-envelope segment. */
+    fun getVoiceEnvPitchTime(playhead: Int, voice: Int): Double {
+        val v = getPlayhead(playhead)?.trackerState?.voices?.getOrNull(voice.coerceIn(0, 19)) ?: return 0.0
+        if (!v.active) return 0.0
+        return v.envPfTimeSec
+    }
 
     /** Set the starting row for the next play call, resetting per-row timing and silencing active voices. */
     fun setTrackerRow(playhead: Int, row: Int) {
@@ -117,6 +265,64 @@ class AudioJSR223Delegate(private val vm: VM) {
         }
     }
 
+    /** Upload an Ixmp "extra samples" block for instrument [slot] (0-255). The payload is
+     *  a flat byte array of `count × 31` patch records — see terranmon.txt "Ixmp. Instrument
+     *  extra samples" for the on-wire field layout. Passing an empty array clears any
+     *  previously-installed patches on this instrument. */
+    fun uploadInstrumentPatches(slot: Int, bytes: IntArray) {
+        val inst = getFirstSnd()?.instruments?.get(slot and 0xFF) ?: return
+        val recordSize = 31
+        if (bytes.isEmpty() || bytes.size < recordSize) {
+            inst.extraPatches = null
+            return
+        }
+        val count = bytes.size / recordSize
+        if (count == 0) { inst.extraPatches = null; return }
+        fun u8 (o: Int) = bytes[o] and 0xFF
+        fun u16(o: Int) = (bytes[o] and 0xFF) or ((bytes[o + 1] and 0xFF) shl 8)
+        fun s16(o: Int): Int { val v = u16(o); return if (v >= 0x8000) v - 0x10000 else v }
+        fun u32(o: Int) =  (bytes[o]     and 0xFF)        or
+                          ((bytes[o + 1] and 0xFF) shl 8) or
+                          ((bytes[o + 2] and 0xFF) shl 16) or
+                          ((bytes[o + 3] and 0xFF) shl 24)
+        val patches = Array(count) { i ->
+            val o = i * recordSize
+            // Patch version byte at offset 0 is parsed but only version 1 is recognised;
+            // a future version bump would gate alternate field layouts here.
+            AudioAdapter.TaudInstPatch(
+                pitchStart        = u16(o + 1),
+                pitchEnd          = u16(o + 3),
+                volumeStart       = u8 (o + 5),
+                volumeEnd         = u8 (o + 6),
+                samplePtr         = u32(o + 7),
+                sampleLength      = u16(o + 11),
+                playStart         = u16(o + 13),
+                loopStart         = u16(o + 15),
+                loopEnd           = u16(o + 17),
+                samplingRate      = u16(o + 19),
+                sampleDetune      = s16(o + 21),
+                loopMode          = u8 (o + 23),
+                defaultPan        = u8 (o + 24),
+                defaultNoteVolume = u8 (o + 25),
+                vibratoSpeed      = u8 (o + 26),
+                vibratoSweep      = u8 (o + 27),
+                vibratoDepth      = u8 (o + 28),
+                vibratoRate       = u8 (o + 29),
+                vibratoWaveform   = u8 (o + 30)
+            )
+        }
+        inst.extraPatches = patches
+    }
+
+    /** Number of Ixmp patches currently installed on instrument [slot], or 0 if none. */
+    fun getInstrumentPatchCount(slot: Int): Int =
+        getFirstSnd()?.instruments?.get(slot and 0xFF)?.extraPatches?.size ?: 0
+
+    /** Clear any Ixmp patches previously uploaded to instrument [slot]. */
+    fun clearInstrumentPatches(slot: Int) {
+        getFirstSnd()?.instruments?.get(slot and 0xFF)?.extraPatches = null
+    }
+
     /** Upload 512 bytes (64 rows × 8 bytes) defining pattern `slot` (0-4094). */
     fun uploadPattern(slot: Int, bytes: IntArray) {
         getFirstSnd()?.playdata?.get(slot and 0xFFF)?.let { pat ->
@@ -167,6 +373,13 @@ class AudioJSR223Delegate(private val vm: VM) {
         getPlayhead(playhead)?.resetParams()
     }
 
+    /** Clear funk-repeat (S$Fx) state (per-voice run-state + per-instrument loop-inversion masks)
+     *  without disturbing tempo / volume / position. Call on a fresh play-from-start so stale funk
+     *  state from a prior playback doesn't bleed into the replay. */
+    fun resetFunkState(playhead: Int) {
+        getPlayhead(playhead)?.resetFunkState()
+    }
+
     fun purgeQueue(playhead: Int) {
         getPlayhead(playhead)?.purgeQueue()
     }

tsvm_core/src/net/torvald/tsvm/GraphicsJSR223Delegate.kt

@@ -149,6 +149,90 @@ class GraphicsJSR223Delegate(private val vm: VM) {
         }
     }
 
+    fun plotRect(x: Int, y: Int, w: Int, h: Int, colour: Int) = plotRect(x, y, w, h, colour, 0)
+
+    /**
+     * @param eff plot effect. 0 — solid, 1 — 50% checkerboard, 2 — 25% checkerboard
+     */
+    fun plotRect(x: Int, y: Int, w: Int, h: Int, colour: Int, eff: Int) {
+        val xs = min(x, x+w).toLong()
+        val xe = max(x, x+w).toLong()
+        val ys = min(y, y+h).toLong()
+        val ye = max(y, y+h).toLong()
+
+        getFirstGPU()?.let {
+            val forYcond = if (eff == 2) (ys until ye step 2) else (ys until ye)
+
+            for (py in forYcond) {
+                when (eff) {
+                    0 -> for (px in xs until xe) {
+                        if (px in 0 until it.config.width && py in 0 until it.config.height) {
+                            it.poke(py * it.config.width + px, colour.toByte())
+                        }
+                    }
+                    1 -> {
+                        val parity = py % 2
+                        val forXcond = if (parity == 0L) (xs until xe step 2) else ((xs+1) until xe step 2)
+
+                        for (px in forXcond) {
+                            if (px in 0 until it.config.width && py in 0 until it.config.height) {
+                                it.poke(py * it.config.width + px, colour.toByte())
+                            }
+                        }
+                    }
+                    2 -> for (px in xs until xe step 2) {
+                        if (px in 0 until it.config.width && py in 0 until it.config.height) {
+                            it.poke(py * it.config.width + px, colour.toByte())
+                        }
+                    }
+                }
+            }
+            it.applyDelay()
+        }
+    }
+
+    fun plotRect2(x: Int, y: Int, w: Int, h: Int, colour: Int) = plotRect2(x, y, w, h, colour, 0)
+
+    /**
+     * @param eff plot effect. 0 — solid, 1 — 50% checkerboard, 2 — 25% checkerboard
+     */
+    fun plotRect2(x: Int, y: Int, w: Int, h: Int, colour: Int, eff: Int) {
+        val xs = min(x, x+w).toLong()
+        val xe = max(x, x+w).toLong()
+        val ys = min(y, y+h).toLong()
+        val ye = max(y, y+h).toLong()
+
+        getFirstGPU()?.let {
+            val forYcond = if (eff == 2) (ys until ye step 2) else (ys until ye)
+
+            for (py in forYcond) {
+                when (eff) {
+                    0 -> for (px in xs until xe) {
+                        if (px in 0 until it.config.width && py in 0 until it.config.height) {
+                            it.poke(262144 + py * it.config.width + px, colour.toByte())
+                        }
+                    }
+                    1 -> {
+                        val parity = py % 2
+                        val forXcond = if (parity == 0L) (xs until xe step 2) else ((xs+1) until xe step 2)
+
+                        for (px in forXcond) {
+                            if (px in 0 until it.config.width && py in 0 until it.config.height) {
+                                it.poke(py * it.config.width + px, colour.toByte())
+                            }
+                        }
+                    }
+                    2 -> for (px in xs until xe step 2) {
+                        if (px in 0 until it.config.width && py in 0 until it.config.height) {
+                            it.poke(py * it.config.width + px, colour.toByte())
+                        }
+                    }
+                }
+            }
+            it.applyDelay()
+        }
+    }
+
     fun plotPixelMode1(x: Int, y: Int, colour: Int, plane: Int) {
         getFirstGPU()?.let {
             val planesize = it.config.width * it.config.height / 4
@@ -159,6 +243,51 @@ class GraphicsJSR223Delegate(private val vm: VM) {
         }
     }
 
+    fun plotRectMode1(x: Int, y: Int, w: Int, h: Int, colour: Int, plane: Int) = plotRectMode1(x, y, w, h, colour, plane, 0)
+
+    /**
+     * @param eff plot effect. 0 — solid, 1 — 50% checkerboard, 2 — 25% checkerboard
+     */
+    fun plotRectMode1(x: Int, y: Int, w: Int, h: Int, colour: Int, plane: Int, eff: Int) {
+        val xs = min(x, x+w).toLong()
+        val xe = max(x, x+w).toLong()
+        val ys = min(y, y+h).toLong()
+        val ye = max(y, y+h).toLong()
+
+        getFirstGPU()?.let {
+            val halfW = it.config.width / 2
+            val halfH = it.config.height / 2
+            val planesize = it.config.width * it.config.height / 4
+            val forYcond = if (eff == 2) (ys until ye step 2) else (ys until ye)
+
+            for (py in forYcond) {
+                when (eff) {
+                    0 -> for (px in xs until xe) {
+                        if (px in 0 until halfW && py in 0 until halfH) {
+                            it.poke(py * halfW + px + planesize * plane, colour.toByte())
+                        }
+                    }
+                    1 -> {
+                        val parity = py % 2
+                        val forXcond = if (parity == 0L) (xs until xe step 2) else ((xs+1) until xe step 2)
+
+                        for (px in forXcond) {
+                            if (px in 0 until halfW && py in 0 until halfH) {
+                                it.poke(py * halfW + px + planesize * plane, colour.toByte())
+                            }
+                        }
+                    }
+                    2 -> for (px in xs until xe step 2) {
+                        if (px in 0 until halfW && py in 0 until halfH) {
+                            it.poke(py * halfW + px + planesize * plane, colour.toByte())
+                        }
+                    }
+                }
+            }
+            it.applyDelay()
+        }
+    }
+
     /**
      * Sets absolute position of scrolling
      */

tsvm_core/src/net/torvald/tsvm/VMJSR223Delegate.kt

@@ -305,7 +305,6 @@ class VMJSR223Delegate(private val vm: VM) {
     fun sleep(time: Long) {
         vm.isIdle.set(true)
         Thread.sleep(time)
-        Thread.sleep(4L)
     }
 
     fun waitForMemChg(addr: Int, andMask: Int, xorMask: Int) {

tsvm_core/src/net/torvald/tsvm/peripheral/HttpModem.kt

@@ -22,7 +22,7 @@ import java.net.URL
  */
 class HttpModem(private val vm: VM, private val artificialDelayBlockSize: Int = 1024, private val artificialDelayWaitTime: Int = -1) : BlockTransferInterface(false, true) {
 
-    private val DBGPRN = true
+    private val DBGPRN = false
 
     private fun printdbg(msg: Any) {
         if (DBGPRN) println("[WgetModem] $msg")

tsvm_core/src/net/torvald/tsvm/peripheral/IOSpace.kt

@@ -3,6 +3,8 @@ package net.torvald.tsvm.peripheral
 import com.badlogic.gdx.Gdx
 import com.badlogic.gdx.Input
 import com.badlogic.gdx.InputProcessor
+import com.badlogic.gdx.math.Vector2
+import com.badlogic.gdx.utils.viewport.Viewport
 import net.torvald.AddressOverflowException
 import net.torvald.DanglingPointerException
 import net.torvald.UnsafeHelper
@@ -10,6 +12,7 @@ import net.torvald.tsvm.CircularArray
 import net.torvald.tsvm.VM
 import net.torvald.tsvm.isNonZero
 import net.torvald.tsvm.toInt
+import java.util.concurrent.atomic.AtomicInteger
 import kotlin.experimental.and
 
 class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
@@ -18,10 +21,25 @@ class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
         return vm
     }
 
-    /** Absolute x-position of the computer GUI */
-    var guiPosX = 0
-    /** Absolute y-position of the computer GUI */
-    var guiPosY = 0
+    /**
+     * Viewport that maps screen pixels (as reported by `Gdx.input.x/y`) to the VM's
+     * logical framebuffer coordinate space. The host application owns the rendering
+     * camera, so the host is responsible for installing a viewport whose world
+     * coordinates match the VM framebuffer (origin top-left, world size = framebuffer
+     * size in pixels) and whose screen rectangle matches where the VM is drawn.
+     *
+     * If left null, `Gdx.input.x/y` is forwarded verbatim — only correct when the VM
+     * occupies the entire window at 1:1 scale.
+     */
+    var inputViewport: Viewport? = null
+    private val tmpMouseVec = Vector2()
+    // Letterbox offset and renderable area inside the inputViewport, set by the host VMGUI.
+    // After unproject, mouse pixel coords are shifted by (inputOriginX, inputOriginY) and
+    // clamped to (inputAreaW, inputAreaH) so apps see VM-screen pixel coords (0..drawWidth).
+    var inputOriginX: Int = 0
+    var inputOriginY: Int = 0
+    var inputAreaW: Int = Int.MAX_VALUE
+    var inputAreaH: Int = Int.MAX_VALUE
 
     /** Accepts a keycode */
     private val keyboardBuffer = CircularArray<Byte>(32, true)
@@ -98,7 +116,12 @@ class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
             in 0..31 -> keyboardBuffer[(addr.toInt())] ?: -1
             in 32..33 -> (mouseX.toInt() shr (adi - 32).times(8)).toByte()
             in 34..35 -> (mouseY.toInt() shr (adi - 34).times(8)).toByte()
-            36L -> mouseDown.toInt().toByte()
+            36L -> {
+                // bit 0: left, bit 1: right, bit 2: middle, bit 6: wheel up, bit 7: wheel down
+                // Wheel bits are latched on scrolled() and cleared on read so a one-shot
+                // detent fires exactly once for the polling app.
+                (mouseButtons or wheelLatch.getAndSet(0)).toByte()
+            }
             37L -> {
                 val key = keyboardBuffer.removeTail() ?: -1
                 keyPushed = !keyboardBuffer.isEmpty  // Clear flag when buffer becomes empty
@@ -280,7 +303,9 @@ class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
 
     private var mouseX: Short = 0
     private var mouseY: Short = 0
-    private var mouseDown = false
+    private var mouseButtons: Int = 0  // bit 0 = LEFT, bit 1 = RIGHT, bit 2 = MIDDLE
+    // bits 6 (wheel up) and 7 (wheel down) — set by scrolled(), cleared on MMIO[36] read
+    private val wheelLatch = AtomicInteger(0)
     private var systemUptime = 0L
     private var rtc = 0L
 
@@ -296,10 +321,28 @@ class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
             keyEventBuffers.fill(0)
 
             if (isFocused) {
-                // store mouse info
-                mouseX = (Gdx.input.x + guiPosX).toShort()
-                mouseY = (Gdx.input.y + guiPosY).toShort()
-                mouseDown = Gdx.input.isTouched
+                // store mouse info; unproject through the host-provided viewport so the
+                // VM sees logical framebuffer pixels regardless of window magnification,
+                // letterboxing or sub-region placement done by an embedding GDX app.
+                val vp = inputViewport
+                val rawX: Int
+                val rawY: Int
+                if (vp != null) {
+                    tmpMouseVec.set(Gdx.input.x.toFloat(), Gdx.input.y.toFloat())
+                    vp.unproject(tmpMouseVec)
+                    rawX = tmpMouseVec.x.toInt()
+                    rawY = tmpMouseVec.y.toInt()
+                }
+                else {
+                    rawX = Gdx.input.x
+                    rawY = Gdx.input.y
+                }
+                // Subtract the letterbox origin so apps see VM-screen pixel coords (0..drawWidth).
+                mouseX = (rawX - inputOriginX).coerceIn(0, inputAreaW - 1).toShort()
+                mouseY = (rawY - inputOriginY).coerceIn(0, inputAreaH - 1).toShort()
+                mouseButtons = (if (Gdx.input.isButtonPressed(Input.Buttons.LEFT))   1 else 0) or
+                               (if (Gdx.input.isButtonPressed(Input.Buttons.RIGHT))  2 else 0) or
+                               (if (Gdx.input.isButtonPressed(Input.Buttons.MIDDLE)) 4 else 0)
 
                 // strobe keys to fill the key read buffer
                 var keysPushed = 0
@@ -313,7 +356,7 @@ class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
                 }
             }
             else {
-                mouseDown = false
+                mouseButtons = 0
             }
         }
 
@@ -376,8 +419,15 @@ class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
         }
     }
 
-    override fun scrolled(p0: Float, p1: Float): Boolean {
-        return false
+    override fun scrolled(amountX: Float, amountY: Float): Boolean {
+        // LibGDX: amountY > 0 = scroll DOWN (toward user), amountY < 0 = scroll UP.
+        // Latch bits 6/7 of MMIO[36]; the latch is cleared the next time MMIO[36] is read.
+        if (Gdx.input.inputProcessor !== this) return false
+        when {
+            amountY < 0f -> wheelLatch.updateAndGet { it or 0x40 }
+            amountY > 0f -> wheelLatch.updateAndGet { it or 0x80 }
+        }
+        return true
     }
 
     override fun keyUp(p0: Int): Boolean {

tsvm_core/src/net/torvald/tsvm/peripheral/TestDiskDrive.kt

@@ -561,7 +561,10 @@ class TestDiskDrive(private val vm: VM, private val driveNum: Int, theRootPath:
                 statusCode.set(STATE_CODE_STANDBY)
             }
             else if (inputString.startsWith("USAGE")) {
-                recipient?.writeout(composePositiveAns("USED123456/TOTAL654321"))
+                val used = rootPath.walkTopDown().filter { it.isFile }.map { it.length() }.sum()
+                    .coerceIn(0L, Int.MAX_VALUE.toLong())
+                val total = rootPath.totalSpace.coerceIn(0L, Int.MAX_VALUE.toLong())
+                recipient?.writeout(composePositiveAns("USED$used/TOTAL$total"))
                 statusCode.set(STATE_CODE_STANDBY)
             }
             else

tsvm_executable/src/net/torvald/tsvm/VMEmuExecutable.kt

@@ -127,7 +127,9 @@ class VMEmuExecutable(val windowWidth: Int, val windowHeight: Int, var panelsX:
     internal fun moveView(oldIndex: Int, newIndex: Int?) {
         if (oldIndex != newIndex) {
             if (newIndex != null) {
-                vms[newIndex] = vms[oldIndex]
+                val moved = vms[oldIndex]
+                vms[newIndex] = moved
+                moved?.vm?.let { applyMouseInputMappingForPanel(it, newIndex) }
             }
             vms[oldIndex] = null
         }
@@ -135,6 +137,28 @@ class VMEmuExecutable(val windowWidth: Int, val windowHeight: Int, var panelsX:
 
     internal fun addVMtoView(vm: VM, profileName: String, index: Int) {
         vms[index] = VMRunnerInfo(vm, profileName)
+        applyMouseInputMappingForPanel(vm, index)
+    }
+
+    /**
+     * Wire the VM's IOSpace so the mouse pixels it sees are relative to its own
+     * GPU framebuffer rather than the whole TsvmEmulator window. Each tiled VM
+     * lives at panel (pposX, pposY) with a letterbox inside that panel, so the
+     * offset is `panel origin + (panel size − GPU size) / 2`.
+     */
+    private fun applyMouseInputMappingForPanel(vm: VM, panelIndex: Int) {
+        val gpu = vm.peripheralTable.getOrNull(1)?.peripheral as? GraphicsAdapter ?: return
+        val pposX = panelIndex % panelsX
+        val pposY = panelIndex / panelsX
+        val gpuW = gpu.config.width
+        val gpuH = gpu.config.height
+        val io = vm.getIO()
+        // TsvmEmulator draws at 1:1 pixel scale, so no GDX viewport is needed.
+        io.inputViewport = null
+        io.inputOriginX = pposX * windowWidth + (windowWidth - gpuW) / 2
+        io.inputOriginY = pposY * windowHeight + (windowHeight - gpuH) / 2
+        io.inputAreaW = gpuW
+        io.inputAreaH = gpuH
     }
 
     internal fun getCurrentlySelectedVM(): VMRunnerInfo? = if (currentVMselection == null) null else vms[currentVMselection!!]
@@ -201,6 +225,7 @@ class VMEmuExecutable(val windowWidth: Int, val windowHeight: Int, var panelsX:
         val vm1 = getVMbyProfileName("Initial VM")!!
         initVMenv(vm1, "Initial VM")
         vms[0] = VMRunnerInfo(vm1, "Initial VM")
+        applyMouseInputMappingForPanel(vm1, 0)
 
         init()
     }
@@ -307,6 +332,11 @@ class VMEmuExecutable(val windowWidth: Int, val windowHeight: Int, var panelsX:
         if (currentVMselection != null && vms[currentVMselection!!]?.vm?.id == vm.id) {
             Gdx.input.inputProcessor = vm.getIO()
         }
+
+        // peripheralTable[1] (the GPU) was disposed and re-installed; re-apply
+        // the mouse mapping so the rebooted VM keeps targeting its own panel.
+        val panelIndex = vms.indexOfFirst { it?.vm?.id == vm.id }
+        if (panelIndex >= 0) applyMouseInputMappingForPanel(vm, panelIndex)
     }
 
     private fun updateGame(delta: Float) {
@@ -434,6 +464,10 @@ class VMEmuExecutable(val windowWidth: Int, val windowHeight: Int, var panelsX:
         this.panelsX = panelsX
         this.panelsY = panelsY
         resize(windowWidth * panelsX, windowHeight * panelsY)
+        // Panel positions shifted, so every VM needs its mouse origin re-mapped.
+        vms.forEachIndexed { index, info ->
+            info?.vm?.let { applyMouseInputMappingForPanel(it, index) }
+        }
     }
 
     override fun resize(width: Int, height: Int) {

tsvm_executable/src/net/torvald/tsvm/VMGUI.kt

@@ -8,6 +8,8 @@ import com.badlogic.gdx.graphics.g2d.SpriteBatch
 import com.badlogic.gdx.graphics.g2d.TextureRegion
 import com.badlogic.gdx.graphics.glutils.FrameBuffer
 import com.badlogic.gdx.graphics.glutils.ShaderProgram
+import com.badlogic.gdx.utils.viewport.StretchViewport
+import com.badlogic.gdx.utils.viewport.Viewport
 import net.torvald.terrarum.DefaultGL32Shaders
 import net.torvald.tsvm.peripheral.*
 import net.torvald.tsvm.peripheral.GraphicsAdapter.Companion.DRAW_SHADER_VERT
@@ -48,6 +50,14 @@ class VMGUI(val loaderInfo: EmulInstance, val viewportWidth: Int, val viewportHe
     lateinit var batch: SpriteBatch
     lateinit var camera: OrthographicCamera
 
+    /**
+     * Maps window pixels to the VM framebuffer (origin top-left, world size =
+     * viewportWidth × viewportHeight). Stretches to fill the whole window so it
+     * matches the `MAGN`-scaled blit at the end of [renderGame]. Handed to
+     * [IOSpace.inputViewport] so mouse coordinates unproject correctly.
+     */
+    lateinit var inputViewport: Viewport
+
     var gpu: GraphicsAdapter? = null
     lateinit var vmRunner: VMRunner
     lateinit var coroutineJob: Thread
@@ -103,9 +113,20 @@ class VMGUI(val loaderInfo: EmulInstance, val viewportWidth: Int, val viewportHe
         gpuFBO = FrameBuffer(Pixmap.Format.RGBA8888, viewportWidth, viewportHeight, false)
         winFBO = FrameBuffer(Pixmap.Format.RGBA8888, viewportWidth, viewportHeight, false)
 
+        val inputCam = OrthographicCamera().also {
+            it.setToOrtho(true, viewportWidth.toFloat(), viewportHeight.toFloat())
+        }
+        inputViewport = StretchViewport(viewportWidth.toFloat(), viewportHeight.toFloat(), inputCam)
+        inputViewport.update(Gdx.graphics.width, Gdx.graphics.height, true)
+
         init()
     }
 
+    override fun resize(width: Int, height: Int) {
+        super.resize(width, height)
+        inputViewport.update(width, height, true)
+    }
+
     private fun init() {
         vm.init()
 
@@ -148,6 +169,11 @@ class VMGUI(val loaderInfo: EmulInstance, val viewportWidth: Int, val viewportHe
         }
 
         Gdx.input.inputProcessor = vm.getIO()
+        vm.getIO().inputViewport = inputViewport
+        vm.getIO().inputOriginX = (viewportWidth - loaderInfo.drawWidth) / 2
+        vm.getIO().inputOriginY = (viewportHeight - loaderInfo.drawHeight) / 2
+        vm.getIO().inputAreaW   = loaderInfo.drawWidth
+        vm.getIO().inputAreaH   = loaderInfo.drawHeight
 
         if (usememvwr) memvwr = Memvwr(vm)
 

xm2taud.py

@@ -16,6 +16,11 @@ Limits:
     - Multi-sample instruments use the sample selected by the *current
       note's* keymap entry; the converter materialises one Taud
       instrument slot per (XM instrument, sample-in-instrument) pair.
+      (Note: it2taud uses the alternate Ixmp project-data extension
+      instead — one Taud instrument per IT instrument, plus an Ixmp
+      patch list for the keyboard mapping. XM could be retrofitted the
+      same way to conserve Taud instrument slots; deferred until any
+      real XM file actually hits the 255-slot cap.)
 
 Pattern length policy:
     - XM patterns ≤ 64 rows → 1 Taud cue with the LEN ($02xx)
@@ -41,6 +46,7 @@ Reference:
 """
 
 import argparse
+import copy
 import math
 import struct
 import sys
@@ -59,7 +65,7 @@ from taud_common import (
     encode_cue, deduplicate_patterns,
     normalise_sample, encode_song_entry, nearest_minifloat, compress_blob,
     CUE_INST_NOP, CUE_INST_HALT, CUE_INST_LEN, cue_instruction_len,
-    build_project_data,
+    build_project_data, detect_subsongs,
 )
 
 
@@ -386,7 +392,7 @@ def encode_note_xm(xm_note: int) -> int:
     if 1 <= xm_note <= 96:
         semis = xm_note - XM_RELNOTE_C4
         val = round(TAUD_C4 + semis * 4096 / 12)
-        return max(1, min(0xFFFD, val))
+        return max(0x20, min(0xFFFF, val))
     return NOTE_NOP
 
 
@@ -694,18 +700,42 @@ def split_patterns_xm(patterns: list):
 
 def remap_b_effects_xm(chunks: list, chunk_map: list,
                        order_list: list, xm_ord_to_taud_cue: dict,
-                       num_channels: int) -> None:
+                       num_channels: int,
+                       *, default_target: int = None,
+                       warn_label: str = '',
+                       chunk_indices=None) -> None:
     """Rewrite XM B (position jump) effects so the argument indexes Taud cues
     rather than XM order positions. (Pattern break Dxx already targets a row,
     no remap needed — the post-break behaviour is "advance to next order",
-    which Taud emulates correctly when the cue ends.)"""
-    for chunk_grid in chunks:
+    which Taud emulates correctly when the cue ends.)
+
+    `default_target`: when a Bxx target isn't in `xm_ord_to_taud_cue` (a
+    cross-subsong jump), rewrite to this cue index instead of preserving
+    the literal target. Use 0 to make cross-song jumps loop the subsong.
+
+    `chunk_indices`: optional iterable; when provided, only these chunks are
+    visited. Used by multi-song to skip unreferenced chunks (avoids spurious
+    cross-song warnings on chunks not emitted in this song).
+    """
+    crossings = 0
+    iter_indices = (chunk_indices if chunk_indices is not None
+                    else range(len(chunks)))
+    for ci in iter_indices:
+        chunk_grid = chunks[ci]
         for ch in range(min(num_channels, len(chunk_grid))):
             for row in chunk_grid[ch]:
                 if row.effect == 0x0B:
                     xm_ord = row.effect_arg & 0xFF
-                    taud_cue = xm_ord_to_taud_cue.get(xm_ord, xm_ord)
-                    row.effect_arg = taud_cue & 0xFF
+                    if xm_ord in xm_ord_to_taud_cue:
+                        row.effect_arg = xm_ord_to_taud_cue[xm_ord] & 0xFF
+                    elif default_target is not None:
+                        crossings += 1
+                        row.effect_arg = default_target & 0xFF
+                    else:
+                        row.effect_arg = xm_ord & 0xFF
+    if crossings and warn_label:
+        vprint(f"  warning: {warn_label}: {crossings} Bxx target(s) cross "
+               f"subsong boundary; clamped to cue {default_target}")
 
 
 def compute_keyoff_zero_marks_xm(taud_cue_list: list, chunks: list,
@@ -1253,6 +1283,147 @@ def _active_channels_xm(h: XMHeader, patterns: list) -> list:
 
 # ── Main assembly ─────────────────────────────────────────────────────────────
 
+def _per_pattern_bxx_xm(patterns: list):
+    """Return callable(pat_idx) → (set_of_bxx_target_orders, kills_fallthrough)
+    for `detect_subsongs`. XM patterns vary in length; `kills_fallthrough` is
+    True when a Bxx (effect 0x0B) appears on the absolute last row.
+    `patterns[pi]` is `(grid, rows)`; `grid` is `[channel][row]`.
+    """
+    def fn(pat_idx: int):
+        if pat_idx < 0 or pat_idx >= len(patterns):
+            return set(), False
+        grid, rows = patterns[pat_idx]
+        targets = set()
+        last_row_has_b = False
+        for ch_rows in grid:
+            n = min(rows, len(ch_rows))
+            for r in range(n):
+                cell = ch_rows[r]
+                if cell.effect == 0x0B:
+                    targets.add(cell.effect_arg & 0xFF)
+                    if r == rows - 1:
+                        last_row_has_b = True
+        return targets, last_row_has_b
+    return fn
+
+
+def _build_song_payload_xm(h: XMHeader, patterns_template: list,
+                           instruments: list, positions: list,
+                           sample_ratio: dict, active_channels: list,
+                           default_pans: list, resolve_inst_slot,
+                           *, song_label: str = 'song') -> tuple:
+    """Build pattern bin + cue sheet + (subset of) song-entry kwargs for
+    one subsong. The caller fills in song_offset, flags_byte, and shared
+    globals.
+
+    Patterns aren't mutated by per-order walks in XM (no recall resolution),
+    but `remap_b_effects_xm` mutates chunk grids — so we deep-copy chunks
+    per song. (`compute_keyoff_zero_marks_xm` only reads.)
+    """
+    chunks, chunk_map, chunk_lens = split_patterns_xm(patterns_template)
+
+    C = len(active_channels)
+
+    cue_list = []
+    pos_to_cue = {}
+    for pos in positions:
+        order = h.order_list[pos]
+        if order >= h.pattern_count or order >= len(chunk_map):
+            continue
+        pos_to_cue[pos] = len(cue_list)
+        for ci in chunk_map[order]:
+            cue_list.append(ci)
+
+    if not cue_list:
+        # Degenerate subsong (e.g. all orders point to invalid patterns).
+        vprint(f"  warning: [{song_label}] no playable cues; emitting halt-only song")
+
+    remap_b_effects_xm(chunks, chunk_map, h.order_list, pos_to_cue, C,
+                       default_target=0, warn_label=song_label,
+                       chunk_indices=set(cue_list))
+
+    keyoff_zero_marks = compute_keyoff_zero_marks_xm(
+        cue_list, chunks, h.channels, instruments, active_channels)
+    if any(keyoff_zero_marks.values()):
+        flagged = sum(len(s) for s in keyoff_zero_marks.values())
+        vprint(f"  [{song_label}] FT2 keyoff-gate: {flagged} key-off cell(s) "
+               f"paired with vol=0 (vol-env-off instruments)")
+
+    total_taud_pats = len(cue_list) * C
+    if total_taud_pats > NUM_PATTERNS_MAX:
+        sys.exit(f"error: [{song_label}] {len(cue_list)} cues × {C} channels = "
+                 f"{total_taud_pats} > {NUM_PATTERNS_MAX} Taud pattern limit.")
+
+    pat_bin = bytearray()
+    for ci in cue_list:
+        cg = chunks[ci]
+        chunk_marks = keyoff_zero_marks.get(ci, frozenset())
+        for vi, ch in enumerate(active_channels):
+            row_marks = {r for (mvi, r) in chunk_marks if mvi == vi}
+            pat_bin += build_pattern_xm(cg, ch, default_pans[vi],
+                                        resolve_inst_slot,
+                                        amiga_mode=not h.linear_freq,
+                                        keyoff_zero_rows=row_marks)
+    pat_bin = rescale_offset_effects_per_slot(
+        bytes(pat_bin), len(cue_list), C, sample_ratio)
+
+    orig_count = len(cue_list) * C
+    pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(pat_bin, orig_count)
+    vprint(f"  [{song_label}] patterns: {orig_count} → {num_taud_pats} unique "
+           f"({orig_count - num_taud_pats} deduplicated)")
+
+    sheet = bytearray(NUM_CUES * CUE_SIZE)
+    for c in range(NUM_CUES):
+        sheet[c * CUE_SIZE:c * CUE_SIZE + CUE_SIZE] = encode_cue([], 0)
+
+    last_active = -1
+    len_cue_count = 0
+    for cue_idx, ci in enumerate(cue_list):
+        if cue_idx >= NUM_CUES: break
+        base_pat = cue_idx * C
+        pats = [pat_remap[base_pat + vi] for vi in range(C)]
+        clen = chunk_lens[ci] if ci < len(chunk_lens) else PATTERN_ROWS
+        if clen < PATTERN_ROWS:
+            instr = cue_instruction_len(clen)
+            len_cue_count += 1
+        else:
+            instr = CUE_INST_NOP
+        sheet[cue_idx * CUE_SIZE:(cue_idx + 1) * CUE_SIZE] = encode_cue(pats, instr)
+        last_active = cue_idx
+
+    if last_active >= 0:
+        if sheet[last_active * CUE_SIZE + 30] == CUE_INST_LEN:
+            vprint(f"  [{song_label}] warning: last active cue {last_active} "
+                   f"had LEN; replaced with HALT (partial tail at song terminus)")
+        sheet[last_active * CUE_SIZE + 30] = CUE_INST_HALT
+        sheet[last_active * CUE_SIZE + 31] = 0x00
+    else:
+        sheet[30] = CUE_INST_HALT
+    if len_cue_count:
+        vprint(f"  [{song_label}] emitted {len_cue_count} LEN cue instruction(s) "
+               f"for partial-length patterns")
+
+    pat_comp = compress_blob(bytes(pat_bin), f"[{song_label}] pattern bin")
+    cue_comp = compress_blob(bytes(sheet),   f"[{song_label}] cue sheet")
+
+    # Speed/tempo are file-wide for XM; pass them through the kwargs so the
+    # outer function fills in shared header fields uniformly.
+    speed = h.default_speed if h.default_speed > 0 else 6
+    tempo = h.default_bpm  if h.default_bpm  > 0 else 125
+    tempo = max(25, min(280, tempo))
+    bpm_stored = (tempo - 25) & 0xFF
+
+    entry_kwargs = dict(
+        num_voices=C,
+        num_patterns=num_taud_pats,
+        bpm_stored=bpm_stored,
+        tick_rate=speed,
+        pat_bin_comp_size=len(pat_comp),
+        cue_sheet_comp_size=len(cue_comp),
+    )
+    return pat_comp, cue_comp, entry_kwargs
+
+
 def assemble_taud(h: XMHeader, patterns: list, instruments: list,
                   with_project_data: bool = True) -> bytes:
     # XM envelope frames advance once per row tick. Tick rate is derived
@@ -1315,139 +1486,69 @@ def assemble_taud(h: XMHeader, patterns: list, instruments: list,
     bpm_stored = (tempo - 25) & 0xFF
     vprint(f"  initial speed={speed}, tempo={tempo} BPM")
 
-    # ── Channels / cue list ─────────────────────────────────────────────────
+    # ── Channels / pattern split (shared) ───────────────────────────────────
     active_channels = _active_channels_xm(h, patterns)
     C = len(active_channels)
     if C == 0:
         sys.exit("error: no active channels found")
 
-    chunks, chunk_map, chunk_lens = split_patterns_xm(patterns)
-
-    taud_cue_list = []
-    xm_ord_to_taud_cue = {}
-    for oi, order in enumerate(h.order_list[:h.order_count]):
-        if order >= h.pattern_count:
-            continue
-        if order >= len(chunk_map):
-            continue
-        xm_ord_to_taud_cue.setdefault(oi, len(taud_cue_list))
-        for ci in chunk_map[order]:
-            taud_cue_list.append(ci)
-
-    if not taud_cue_list:
-        sys.exit("error: order list resolved to no playable cues")
-
-    remap_b_effects_xm(chunks, chunk_map, h.order_list, xm_ord_to_taud_cue, C)
-
-    # FT2 vol-env-off key-off gating: pre-compute per-(chunk, voice, row) flags
-    # for key-off cells whose bound XM instrument has volume envelope disabled.
-    # build_pattern_xm pairs each flagged key-off with `SEL_SET vol=0` so the
-    # IT-style Taud engine reproduces FT2's channel-volume zeroing gate.
-    keyoff_zero_marks = compute_keyoff_zero_marks_xm(
-        taud_cue_list, chunks, h.channels, instruments, active_channels)
-    if any(keyoff_zero_marks.values()):
-        flagged = sum(len(s) for s in keyoff_zero_marks.values())
-        vprint(f"  FT2 keyoff-gate: {flagged} key-off cell(s) paired with vol=0 "
-               f"(vol-env-off instruments)")
-
-    # ── Pattern bin ─────────────────────────────────────────────────────────
-    total_taud_pats = len(taud_cue_list) * C
-    if total_taud_pats > NUM_PATTERNS_MAX:
-        sys.exit(f"error: {len(taud_cue_list)} cues × {C} channels = "
-                 f"{total_taud_pats} > {NUM_PATTERNS_MAX} Taud pattern limit.")
-
     # Default pan per active channel: alternate L/R FT2-style (0,12,12,0,...).
     def _xm_default_pan(idx: int) -> int:
         side = idx % 4
         return 16 if side in (0, 3) else 47
     default_pans = [_xm_default_pan(i) for i in range(C)]
 
-    pat_bin = bytearray()
-    for ci in taud_cue_list:
-        cg = chunks[ci]
-        chunk_marks = keyoff_zero_marks.get(ci, frozenset())
-        for vi, ch in enumerate(active_channels):
-            row_marks = {r for (mvi, r) in chunk_marks if mvi == vi}
-            pat_bin += build_pattern_xm(cg, ch, default_pans[vi],
-                                        resolve_inst_slot,
-                                        amiga_mode=not h.linear_freq,
-                                        keyoff_zero_rows=row_marks)
-    # Rescale TOP_O sample-offset args per channel using the active slot's
-    # ratio (combined global + per-sample). Walks pat_bin in cue-major /
-    # channel-minor order, tracking the most recent inst byte seen on each
-    # channel — must run before deduplication so the channel state stays
-    # linear.
-    pat_bin = rescale_offset_effects_per_slot(
-        bytes(pat_bin), len(taud_cue_list), C, sample_ratio)
-
-    orig_count = len(taud_cue_list) * C
-    pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(pat_bin, orig_count)
-    vprint(f"  patterns: {orig_count} → {num_taud_pats} unique "
-           f"({orig_count - num_taud_pats} deduplicated)")
-
-    # ── Cue sheet ───────────────────────────────────────────────────────────
-    sheet = bytearray(NUM_CUES * CUE_SIZE)
-    for c in range(NUM_CUES):
-        sheet[c * CUE_SIZE:c * CUE_SIZE + CUE_SIZE] = encode_cue([], 0)
-
-    last_active = -1
-    len_cue_count = 0
-    for cue_idx, ci in enumerate(taud_cue_list):
-        if cue_idx >= NUM_CUES:
-            break
-        base_pat = cue_idx * C
-        pats = [pat_remap[base_pat + vi] for vi in range(C)]
-        clen = chunk_lens[ci] if ci < len(chunk_lens) else PATTERN_ROWS
-        if clen < PATTERN_ROWS:
-            instr = cue_instruction_len(clen)
-            len_cue_count += 1
-        else:
-            instr = CUE_INST_NOP
-        sheet[cue_idx * CUE_SIZE:(cue_idx + 1) * CUE_SIZE] = encode_cue(pats, instr)
-        last_active = cue_idx
-
-    if last_active >= 0:
-        if sheet[last_active * CUE_SIZE + 30] == CUE_INST_LEN:
-            vprint(f"  warning: last active cue {last_active} had LEN; "
-                   f"replaced with HALT (partial tail at song terminus)")
-        sheet[last_active * CUE_SIZE + 30] = CUE_INST_HALT
-        sheet[last_active * CUE_SIZE + 31] = 0x00
+    # ── Detect subsongs ──────────────────────────────────────────────────────
+    # XM has no terminator marker; `order_count` bounds the live order list.
+    # Out-of-range pattern refs (≥ pattern_count) are skipped during playback,
+    # so we feed the detector a slice of length `order_count` and treat
+    # everything ≥ pattern_count as a skip.
+    orders_view = list(h.order_list[:h.order_count])
+    skip_set = set(range(h.pattern_count, 256))
+    subsongs = detect_subsongs(orders_view, _per_pattern_bxx_xm(patterns),
+                               terminators=(),
+                               skip_marker=skip_set)
+    if not subsongs:
+        vprint("  warning: no traversable orders in source; emitting empty song")
+        subsongs = [{'entry': 0, 'positions': []}]
+    n_songs = len(subsongs)
+    if n_songs == 1:
+        vprint(f"  detected 1 song ({len(subsongs[0]['positions'])} orders)")
     else:
-        sheet[30] = CUE_INST_HALT
-    if len_cue_count:
-        vprint(f"  emitted {len_cue_count} LEN cue instruction(s) "
-               f"for partial-length patterns")
+        vprint(f"  detected {n_songs} subsongs:")
+        for i, ss in enumerate(subsongs):
+            vprint(f"    song {i}: entry@{ss['entry']}, {len(ss['positions'])} orders")
 
-    # ── Header / song table ─────────────────────────────────────────────────
-    song_offset = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY
-    sig    = (SIGNATURE + b' ' * 14)[:14]
+    # ── Build per-song payloads ──────────────────────────────────────────────
+    song_payloads = []
+    for i, ss in enumerate(subsongs):
+        label = f"song {i}" if n_songs > 1 else "song"
+        song_payloads.append(_build_song_payload_xm(
+            h, patterns, instruments, ss['positions'],
+            sample_ratio, active_channels, default_pans,
+            resolve_inst_slot,
+            song_label=label))
 
-    pat_comp = compress_blob(bytes(pat_bin), "pattern bin")
-    cue_comp = compress_blob(bytes(sheet),   "cue sheet")
+    # ── Layout offsets and song table ────────────────────────────────────────
+    song_table_off = TAUD_HEADER_SIZE + comp_size
+    first_song_off = song_table_off + TAUD_SONG_ENTRY * n_songs
 
-    # Flags byte:
-    #   bits 0-1 (ff) = tone mode. ff=1 (Amiga period slides) when XM uses the Amiga
-    #                   period table; ff=0 otherwise. Pan law is fixed engine-wide to
-    #                   the equal-energy — no `p` bit any more.
-    #   bit 2         = reserved (was 'm' fadeout-zero policy; removed). XM fadeout values
-    #                   are now scaled per-instrument above (÷32 with round-to-nearest), so
-    #                   the engine sees Taud-native units and uses its single divisor of 1024.
     flags_byte = (0x00 if h.linear_freq else 0x01)
-    song_table = encode_song_entry(
-        song_offset=song_offset,
-        num_voices=C,
-        num_patterns=num_taud_pats,
-        bpm_stored=bpm_stored,
-        tick_rate=speed,
-        base_note=0xA000,
-        base_freq=8363.0,
-        flags_byte=flags_byte,
-        pat_bin_comp_size=len(pat_comp),
-        cue_sheet_comp_size=len(cue_comp),
-        global_vol=0xFF,
-        mixing_vol=0x80,
-    )
-    assert len(song_table) == TAUD_SONG_ENTRY
+    song_table = bytearray()
+    cur_off = first_song_off
+    for pat_comp, cue_comp, entry_kwargs in song_payloads:
+        # Header BPM/speed go into per-song; flags is shared (XM doesn't switch
+        # period mode mid-file).
+        entry = encode_song_entry(song_offset=cur_off,
+                                  flags_byte=flags_byte,
+                                  global_vol=0xFF,
+                                  mixing_vol=0x80,
+                                  base_note=0xA000,
+                                  base_freq=8363.0,
+                                  **entry_kwargs)
+        assert len(entry) == TAUD_SONG_ENTRY
+        song_table += entry
+        cur_off += len(pat_comp) + len(cue_comp)
 
     # Project Data (optional). XM nests samples under instruments and the
     # converter creates one Taud slot per (xm_inst, sample) pair, so SNam is
@@ -1466,20 +1567,28 @@ def assemble_taud(h: XMHeader, patterns: list, instruments: list,
             sample_names=smp_names,
         )
         if proj_data:
-            proj_off = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY \
-                       + len(pat_comp) + len(cue_comp)
+            proj_off = cur_off
             vprint(f"  project data: {len(proj_data)} bytes @ offset {proj_off}")
 
+    sig = (SIGNATURE + b' ' * 14)[:14]
     header = (
         TAUD_MAGIC +
-        bytes([TAUD_VERSION, 1]) +
+        bytes([TAUD_VERSION, n_songs & 0xFF]) +
         struct.pack('<I', comp_size) +
         struct.pack('<I', proj_off) +
         sig
     )
     assert len(header) == TAUD_HEADER_SIZE
 
-    return header + compressed + song_table + pat_comp + cue_comp + proj_data
+    out = bytearray()
+    out += header
+    out += compressed
+    out += song_table
+    for pat_comp, cue_comp, _ in song_payloads:
+        out += pat_comp
+        out += cue_comp
+    out += proj_data
+    return bytes(out)
 
 
 # ── Main ──────────────────────────────────────────────────────────────────────