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

@@ -62,9 +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/hopper/*

.idea/libraries/badlogicgames_gdx.xml

@@ -0,0 +1,11 @@
+<component name="libraryTable">
+  <library name="badlogicgames.gdx" type="repository">
+    <properties maven-id="com.badlogicgames.gdx:gdx:1.12.1" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/com/badlogicgames/gdx/gdx/1.12.1/gdx-1.12.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/badlogicgames/gdx/gdx-jnigen-loader/2.3.1/gdx-jnigen-loader-2.3.1.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/libraries/badlogicgames_gdx_backend_lwjgl3.xml

@@ -0,0 +1,62 @@
+<component name="libraryTable">
+  <library name="badlogicgames.gdx.backend.lwjgl3" type="repository">
+    <properties maven-id="com.badlogicgames.gdx:gdx-backend-lwjgl3:1.12.1" />
+    <CLASSES>
+      <root url="jar://$MAVEN_REPOSITORY$/com/badlogicgames/gdx/gdx-backend-lwjgl3/1.12.1/gdx-backend-lwjgl3-1.12.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/badlogicgames/gdx/gdx/1.12.1/gdx-1.12.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/badlogicgames/gdx/gdx-jnigen-loader/2.3.1/gdx-jnigen-loader-2.3.1.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3-natives-linux.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3-natives-linux-arm32.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3-natives-linux-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3-natives-macos.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3-natives-macos-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3-natives-windows.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl/3.3.3/lwjgl-3.3.3-natives-windows-x86.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3-natives-linux.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3-natives-linux-arm32.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3-natives-linux-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3-natives-macos.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3-natives-macos-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3-natives-windows.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-glfw/3.3.3/lwjgl-glfw-3.3.3-natives-windows-x86.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3-natives-linux.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3-natives-linux-arm32.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3-natives-linux-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3-natives-macos.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3-natives-macos-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3-natives-windows.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-jemalloc/3.3.3/lwjgl-jemalloc-3.3.3-natives-windows-x86.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3-natives-linux.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3-natives-linux-arm32.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3-natives-linux-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3-natives-macos.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3-natives-macos-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3-natives-windows.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-openal/3.3.3/lwjgl-openal-3.3.3-natives-windows-x86.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3-natives-linux.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3-natives-linux-arm32.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3-natives-linux-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3-natives-macos.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3-natives-macos-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3-natives-windows.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-opengl/3.3.3/lwjgl-opengl-3.3.3-natives-windows-x86.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3-natives-linux.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3-natives-linux-arm32.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3-natives-linux-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3-natives-macos.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3-natives-macos-arm64.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3-natives-windows.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/lwjgl/lwjgl-stb/3.3.3/lwjgl-stb-3.3.3-natives-windows-x86.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/com/badlogicgames/jlayer/jlayer/1.0.1-gdx/jlayer-1.0.1-gdx.jar!/" />
+      <root url="jar://$MAVEN_REPOSITORY$/org/jcraft/jorbis/0.0.17/jorbis-0.0.17.jar!/" />
+    </CLASSES>
+    <JAVADOC />
+    <SOURCES />
+  </library>
+</component>

.idea/markdown.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="MarkdownSettings">
+    <option name="previewPanelProviderInfo">
+      <ProviderInfo name="Compose (experimental)" className="com.intellij.markdown.compose.preview.ComposePanelProvider" />
+    </option>
+    <option name="splitLayout" value="SHOW_EDITOR" />
+  </component>
+</project>

.idea/runConfigurations/AppLoader.xml

@@ -3,7 +3,7 @@
     <option name="ALTERNATIVE_JRE_PATH" value="21" />
     <option name="MAIN_CLASS_NAME" value="net.torvald.tsvm.AppLoader" />
     <module name="tsvm_executable" />
-    <option name="VM_PARAMETERS" value="-ea --upgrade-module-path=lib/compiler-23.1.10.jar:lib/compiler-management-23.1.10.jar:lib/truffle-compiler-23.1.10.jar:lib/truffle-api-23.1.10.jar:lib/truffle-runtime-23.1.10.jar:lib/polyglot-23.1.10.jar:lib/collections-23.1.10.jar:lib/word-23.1.10.jar:lib/nativeimage-23.1.10.jar:lib/jniutils-23.1.10.jar -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI --add-exports=java.base/jdk.internal.misc=jdk.internal.vm.compiler" />
+    <option name="VM_PARAMETERS" value="-ea --upgrade-module-path=lib/compiler-23.1.10.jar:lib/compiler-management-23.1.10.jar:lib/truffle-compiler-23.1.10.jar:lib/truffle-api-23.1.10.jar:lib/truffle-runtime-23.1.10.jar:lib/polyglot-23.1.10.jar:lib/collections-23.1.10.jar:lib/word-23.1.10.jar:lib/nativeimage-23.1.10.jar:lib/jniutils-23.1.10.jar -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -XX:+UseZGC -XX:+UseDynamicNumberOfGCThreads --add-exports=java.base/jdk.internal.misc=jdk.internal.vm.compiler" />
     <extension name="coverage">
       <pattern>
         <option name="PATTERN" value="net.torvald.tsvm.*" />

.idea/runConfigurations/TsvmEmulator.xml

@@ -2,7 +2,7 @@
   <configuration default="false" name="TsvmEmulator" type="Application" factoryName="Application" nameIsGenerated="true">
     <option name="MAIN_CLASS_NAME" value="net.torvald.tsvm.TsvmEmulator" />
     <module name="tsvm_executable" />
-    <option name="VM_PARAMETERS" value="-ea --upgrade-module-path=lib/compiler-23.1.10.jar:lib/compiler-management-23.1.10.jar:lib/truffle-compiler-23.1.10.jar:lib/truffle-api-23.1.10.jar:lib/truffle-runtime-23.1.10.jar:lib/polyglot-23.1.10.jar:lib/collections-23.1.10.jar:lib/word-23.1.10.jar:lib/nativeimage-23.1.10.jar:lib/jniutils-23.1.10.jar -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI --add-exports=java.base/jdk.internal.misc=jdk.internal.vm.compiler" />
+    <option name="VM_PARAMETERS" value="-ea --upgrade-module-path=lib/compiler-23.1.10.jar:lib/compiler-management-23.1.10.jar:lib/truffle-compiler-23.1.10.jar:lib/truffle-api-23.1.10.jar:lib/truffle-runtime-23.1.10.jar:lib/polyglot-23.1.10.jar:lib/collections-23.1.10.jar:lib/word-23.1.10.jar:lib/nativeimage-23.1.10.jar:lib/jniutils-23.1.10.jar -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -XX:+UseZGC -XX:+UseDynamicNumberOfGCThreads --add-exports=java.base/jdk.internal.misc=jdk.internal.vm.compiler" />
     <extension name="coverage">
       <pattern>
         <option name="PATTERN" value="net.torvald.tsvm.*" />

2taud.sh

@@ -0,0 +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

@@ -18,6 +18,31 @@ Documentation for TSVM and TVDOS are available on `./doc/*.tex` as machine-reada
 
 Documentatino for TSVM architecture is available on `terranmon.txt`
 
+## Reference Materials
+
+Third-party source-code references that inform TSVM implementations live in
+`reference_materials/<topic>/`. Each topic folder has a `README.md` that
+summarises the takeaway and points back into the verbatim source files.
+**Consult these before reimplementing tracker / codec / DSP behaviour from
+memory** — TSVM aims to match the audible behaviour of the originals.
+
+Current topics:
+
+- `reference_materials/tracker_filter/` — Impulse Tracker / OpenMPT / Schism
+  Tracker resonant low-pass filter source. Defines the cutoff formula, the
+  resonance damping curve, and the **IIR-only 2-pole topology** (NOT a
+  biquad — no feedforward x[n−1] / x[n−2] terms) that `AudioAdapter.kt` uses
+  for Taud playback.
+- `reference_materials/ft2-clone` — Modernised clone for the original FastTracker 2
+- `reference_materials/impulse-tracker` — The original source code for ImpulseTracker
+- `reference_materials/MilkyTracker` — FastTracker 2 compatible tracker
+- `reference_materials/schismtracker` — Open-source re-implementation of ImpulseTracker
+- `reference_materials/pt2-clone` — Open-source re-implementation of ProTracker 2
+
+When fetching new references, copy the relevant upstream files verbatim into
+a topic folder, write a `README.md` summarising the relevant maths /
+algorithms with file:line citations, and add an entry here.
+
 ## Architecture
 
 ### Core Components
@@ -68,12 +93,12 @@ Use the build scripts in `buildapp/`:
 
 ### Prerequisites
 
-1. Download JDK 17 runtimes to `~/Documents/openjdk/*` with specific naming:
-   - `jdk-17.0.1-x86` (Linux AMD64)
-   - `jdk-17.0.1-arm` (Linux Aarch64) 
-   - `jdk-17.0.1-windows` (Windows AMD64)
-   - `jdk-17.0.1.jdk-arm` (macOS Apple Silicon)
-   - `jdk-17.0.1.jdk-x86` (macOS Intel)
+1. Download JDK 21 runtimes to `~/Documents/openjdk/*` with specific naming:
+   - `jdk-21.0.1-x86` (Linux AMD64)
+   - `jdk-21.0.1-arm` (Linux Aarch64) 
+   - `jdk-21.0.1-windows` (Windows AMD64)
+   - `jdk-21.0.1.jdk-arm` (macOS Apple Silicon)
+   - `jdk-21.0.1.jdk-x86` (macOS Intel)
 
 2. Run `jlink` commands to create custom Java runtimes in `out/runtime-*` directories
 
@@ -91,6 +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:
@@ -130,6 +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
@@ -393,3 +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.

README.md

@@ -1,8 +1,222 @@
 ![tsvm](tsvm_screenshot.png)
 
-**tsvm** /tiː.ɛs.viː.ɛm/ is a virtual machine with the architecture that mimics the 8-bit era of
-computers, and runs programs written in Javascript.
+# tsvm
 
-**tsvm** repository includes the virtual machine itself, the reference BIOS
-implementation and a DOS; BASIC is provided by the [TerranBASIC](https://github.com/curioustorvald/TerranBASIC)
-repository.
+**tsvm** /tiː.ɛs.viː.ɛm/ is a fantasy computer platform: a virtual machine whose
+architecture is inspired by the 8-bit and early 16-bit home computers, built
+from the ground up around running JavaScript as its native machine code.
+
+What started as "an 8-bit-flavoured VM that runs JS" has grown into a complete,
+self-hosted retro computing ecosystem — with its own BIOS, operating system,
+filesystem, video and audio codecs, video display coprocessor with its own
+assembly language, tracker music format, and a stack of userland tools that
+together come closer to a small alternate-history computer line than a
+single-binary emulator.
+
+This repository contains the virtual machine core, the reference BIOS
+implementations, the **TVDOS** operating system, the **Videotron2K** video
+display controller, hardware-accelerated codec backends for the **TEV / TAV /
+TAD** media formats, and the multi-platform packaging scripts. The
+[TerranBASIC](https://github.com/curioustorvald/TerranBASIC) repository
+provides the matching BASIC dialect that ships on the system disk.
+
+## What's actually in here
+
+### The virtual machine
+
+- **VM core** (`tsvm_core/`) — memory model, peripheral bus, MMIO, JS
+  sandboxing through GraalVM, watchdog, DMA engine, and cooperative scheduling.
+  Up to 8 hot-pluggable peripheral slots, each with a dedicated MMIO window
+  and memory-space window mapped into the VM's negative address range.
+- **Multiple BIOS implementations** (`assets/bios/`) — including the reference
+  `tsvmbios.js`, an OpenBIOS variant, the TBM-BIOS for TerranBASIC machines,
+  and the Pip-Boy-style `pipboot.rom`. BIOSes are first-class swappable
+  components, not a fixed boot blob.
+- **Reference monitor / debugger** (`mon.js`) for poking at memory and
+  peripherals from a running machine.
+- **Multi-platform packaging** (`buildapp/`) — scripts to produce Linux x86_64
+  / ARM64 AppImages, macOS Intel / Apple Silicon bundles, and Windows builds,
+  each with its own `jlink`-trimmed JDK 21 runtime.
+
+### Peripherals (the "hardware")
+
+Living under `tsvm_core/src/net/torvald/tsvm/peripheral/`:
+
+- **Graphics adapters** — the standard `GraphicsAdapter`, plus `TexticsAdapter`
+  for text-mode framebuffers, `ExtDisp` for external displays, and a
+  `RemoteGraphicsAdapter` for networked rendering.
+- **Audio devices** — `AudioAdapter` (the main programmable sound chip with
+  PCM channels, an Impulse Tracker-style resonant low-pass filter, and a
+  hardware-accelerated **TAD** decoder), `OpenALBufferedAudioDevice`, and the
+  `MP2Env` MPEG audio environment.
+- **Disk drives** — `TevdDiskDrive` (TEVD custom filesystem),
+  `ClusteredDiskDrive`, `TestDiskDrive`, and a latency-simulator script for
+  testing slow-storage behaviour.
+- **Networking and serial** — `HttpModem`, `HSDPA` / `HostFileHSDPA` for
+  high-speed packet I/O, `SerialStdioHost`, `BlockTransferInterface` /
+  `BlockTransferPort`.
+- **Terminals and displays** — `TTY`, `GlassTty`, `TermSim`, and a
+  `CharacterLCDdisplay` for HD44780-flavoured projects.
+- **Memory expansion** — `RamBank` for bank-switched memory, plus a
+  programmable `TestFunctionGenerator`.
+
+### Videotron2K — the video coprocessor
+
+Videotron2K is a programmable video display controller with its **own
+assembly-like language**, six general registers (`r1`–`r6`), special registers
+(`tmr`, `frm`, `px`, `py`, `c1`–`c6`), a scene-based programming model, and
+conditional postfixes (`zr`, `nz`, `gt`, `ls`, `ge`, `le`). Programs declare
+`SCENE` blocks and dispatch them with `perform`. Drawing primitives include
+`plot`, `fillin`, `fillscr`, and `goto`. See `Videotron2K.md` and the VDC
+implementation under `tsvm_core/.../vdc/`.
+
+### TVDOS — the operating system
+
+`assets/disk0/tvdos/` is a complete DOS-style userland:
+
+- **Kernel and drivers** — `TVDOS.SYS`, `HSDPADRV.SYS`, `hyve.SYS`,
+  installable drivers under `moviedev/` and `tuidev/`.
+- **Custom filesystem** — TEVD, with the on-disk format documented in
+  `tvdos/filesystem.md`.
+- **Internationalisation** — Colemak / Dvorak / QWERTY keymaps and an `i18n/`
+  resource tree.
+- **Userland binaries** (`tvdos/bin/`) — a shell (`command.js`), file tools
+  (`hexdump`, `less`, `tee`, `touch`, `printfile`, `writeto`, `defrag`,
+  `lfs`, `drives`), an editor (`edit.js`), a file manager (`zfm.js`), a
+  network fetcher (`geturl`), gzip/Zstd helpers, palette tools, and a battery
+  of media players (`playmp2`, `playpcm`, `playwav`, `playmv1`, `playtev`,
+  `playtav`, `playtad`, `playucf`).
+- **Taut tracker** — a full in-VM tracker (`taut.js`,
+  `taut_instredit.js`, `taut_sampleedit.js`, `taut_notationedit.js`,
+  `taut_fileop.js`) with its own font and chrome assets.
+
+### Codecs and media formats
+
+tsvm ships a small but serious codec lab. Encoders are written in C and live
+in `video_encoder/`; decoders are split between JavaScript players in TVDOS
+and hardware-accelerated Kotlin backends in the VM core.
+
+- **iPF (Type 1 / 2 / 1-delta)** — picture and legacy movie format. Encoders:
+  `encodeipf.js`, `encodemov.js`, `encodemov2.js`. Documented in
+  `terranmon.txt`.
+- **TEV (TSVM Enhanced Video)** — modern DCT codec with motion compensation,
+  16×16 blocks, YCoCg-R 4:2:0, and either quality-mode or bitrate-mode rate
+  control. Encoder: `video_encoder/encoder_tev.c`. Decoder: `playtev.js`,
+  with `tevDecode` / `tevIdct8x8` / `tevMotionCopy8x8` accelerated in
+  `GraphicsJSR223Delegate.kt`.
+- **TAV (TSVM Advanced Video)** — successor to TEV based on the Discrete
+  Wavelet Transform. Five wavelet types (5/3 reversible, 9/7 irreversible,
+  CDF 13/7, DD-4, Haar), 6-level decomposition, EZBC sparsity coding,
+  perceptual quantisation, and an optional **3D temporal DWT** that encodes
+  whole groups of pictures as one unified wavelet tree. Includes a packet
+  inspector (`tav_inspector.c`) and coefficient visualiser
+  (`tav_visualise_coefficients.c`).
+- **TAD (TSVM Advanced Audio)** — perceptual audio codec at 32 kHz stereo,
+  using CDF 9/7 wavelets, M/S decorrelation, gamma compression, pre-emphasis,
+  EZBC, and Zstd. Achieves ~2.5:1 compression vs. PCMu8 at quality 3 while
+  preserving the full 0–16 kHz band. Designed to be embeddable inside TAV so
+  audio chunks can align with video GOP boundaries.
+- **Taud** — tracker module format with conversion tools from
+  the major formats: `it2taud.py` (Impulse Tracker), `mod2taud.py`
+  (ProTracker / FastTracker), `s3m2taud.py` (Scream Tracker 3), plus
+  `2taud.sh` and shared helpers in `taud_common.py`. Note effects are
+  documented in `TAUD_NOTE_EFFECTS.md`. The `AudioAdapter` runs the same
+  IIR-only 2-pole resonant low-pass topology used by Impulse Tracker /
+  OpenMPT / Schism.
+- **MP2** — reference MPEG-1 Layer II environment via `MP2Env.kt` and
+  `playmp2.js`.
+
+### Languages and runtimes
+
+- **JavaScript** is the VM's native code, executed by GraalVM in a sandboxed
+  context with a curated set of host bindings (graphics, audio, filesystem,
+  DMA, compression, networking, low-level peek/poke).
+- **TerranBASIC** is provided by the
+  [TerranBASIC](https://github.com/curioustorvald/TerranBASIC) repository and
+  shipped as `tbas` on the system disk. The `TerranBASICexecutable/` subproject
+  packages a BASIC-only flavour of the machine.
+- **Videotron2K assembly** for VDC programs.
+
+### Documentation
+
+- `terranmon.txt` — the architecture reference (memory map, peripheral
+  protocol, codec bitstreams).
+- `doc/*.tex` — machine-readable LaTeX sources for the TSVM and TVDOS manuals,
+  built with `doc/makepdf.sh`.
+- `Videotron2K.md` — VDC programming guide.
+- `TAUD_NOTE_EFFECTS.md` — tracker effect reference.
+- `CLAUDE.md` — a condensed map of the project for collaborators (and
+  language-model assistants) working in the tree.
+
+## Building and running
+
+### Prerequisites
+
+JDK 21 runtimes laid out under `~/Documents/openjdk/` with platform-specific
+names:
+
+- `jdk-21.0.1-x86` — Linux AMD64
+- `jdk-21.0.1-arm` — Linux Aarch64
+- `jdk-21.0.1-windows` — Windows AMD64
+- `jdk-21.0.1.jdk-x86` — macOS Intel
+- `jdk-21.0.1.jdk-arm` — macOS Apple Silicon
+
+`jlink` is then used to produce trimmed runtimes under `out/runtime-*`.
+
+### Common entry points
+
+- **Run the emulator** — `TsvmEmulator.java` (in `tsvm_executable/`).
+- **Run TerranBASIC-only build** — `TerranBASIC.java` (in
+  `TerranBASICexecutable/`).
+- **Package an installable bundle** — pick the right script in `buildapp/`:
+    - `build_app_linux_x86.sh`
+    - `build_app_linux_arm.sh`
+    - `build_app_mac_x86.sh`
+    - `build_app_mac_arm.sh`
+    - `build_app_windows_x86.sh`
+- **Build C encoders** — in `video_encoder/`: `make` (TEV), `make tav`,
+  `make tad`.
+
+### Encoding sample media
+
+```bash
+# Quality-mode TEV encode
+./encoder_tev -i input.mp4 -o clip.tev -q 3
+
+# TAV with 9/7 wavelet, quality 4
+./encoder_tav -i input.mp4 -w 1 -q 4 -o clip.tav
+
+# TAV with 3D temporal DWT (GOP-unified encoding)
+./encoder_tav -i input.mp4 --temporal-dwt -o clip.tav
+
+# TAD audio at the highest quality
+./encoder_tad -i input.mp4 -o track.tad -q 5
+```
+
+Then, inside TVDOS:
+
+```
+A:\> playtev clip.tev
+A:\> playtav clip.tav
+A:\> playtad track.tad
+```
+
+## Repository layout
+
+```
+tsvm_core/             VM core, peripherals, VDC, JS bindings (Kotlin)
+tsvm_executable/       Main emulator GUI (LibGDX)
+TerranBASICexecutable/ For creatingTerranBASIC executable
+assets/bios/           BIOS ROMs and source
+assets/disk0/          Boot disk image, including all of TVDOS
+video_encoder/         C encoders, decoder libs, inspectors (TEV / TAV / TAD)
+ipf_encoder/           Reference iPF encoder
+doc/                   LaTeX sources for the TSVM / TVDOS manuals
+buildapp/              Per-platform packaging scripts
+My_BASIC_Programs/     Example BASIC programs
+*.py, *.sh, *.kts      Conversion tools and ad-hoc utilities
+```
+
+## Licence
+
+See `COPYING`.

TerranBASICexecutable/TerranBASICexecutable.iml

@@ -10,5 +10,7 @@
     <orderEntry type="module" module-name="tsvm_core" />
     <orderEntry type="library" name="TerranVirtualDisk" level="project" />
     <orderEntry type="library" name="lib" level="project" />
+    <orderEntry type="library" name="badlogicgames.gdx" level="project" />
+    <orderEntry type="library" name="badlogicgames.gdx.backend.lwjgl3" level="project" />
   </component>
 </module>

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

@@ -122,8 +122,39 @@ class VMGUI(val loaderInfo: EmulInstance, val viewportWidth: Int, val viewportHe
     private var rebootRequested = false
 
     private fun reboot() {
-        vmRunner.close()
-        coroutineJob.interrupt()
+        // Order is critical: stop ALL execution first, then dispose peripherals
+        // before re-initialising. Without this, the old JS thread races the new
+        // one on shared VM memory / IO state and can SIGSEGV on disposed peripherals.
+
+        // 1. Stop parallel/child contexts. park() interrupts and joins them.
+        vm.park()
+        vm.poke(-90L, -128)
+
+        // 2. Interrupt the main runner thread and cancel the GraalVM context.
+        if (::coroutineJob.isInitialized) coroutineJob.interrupt()
+        try { if (::vmRunner.isInitialized) vmRunner.close() } catch (_: Throwable) {}
+
+        // 3. Wait for the main runner thread to actually finish.
+        if (::coroutineJob.isInitialized && coroutineJob !== Thread.currentThread()) {
+            try {
+                coroutineJob.join(2000L)
+                if (coroutineJob.isAlive) {
+                    System.err.println("[VMGUI] runner ${vm.id} did not exit within 2s; proceeding anyway")
+                    coroutineJob.interrupt()
+                }
+            }
+            catch (_: InterruptedException) {
+                Thread.currentThread().interrupt()
+            }
+        }
+
+        // 4. Now it's safe to release native resources held by peripherals.
+        for (i in 1 until vm.peripheralTable.size) {
+            try {
+                vm.peripheralTable[i].peripheral?.dispose()
+            }
+            catch (_: Throwable) {}
+        }
 
         vm.init()
         init()

assets/bios/tsvmbios.js

@@ -1,5 +1,5 @@
 con.reset_graphics();con.curs_set(0);con.clear();
-graphics.resetPalette();graphics.setBackground(0,0,0);
+graphics.resetPalette();graphics.setPalette(0, 0, 0, 0, 15);graphics.setBackground(0,0,0);
 
 let logo = gzip.decomp(base64.atob("H4sICJoBTGECA3Rzdm1sb2dvLnJhdwDtneu2nCoQhPf7v6xLEMUL5lxyVk6yhxm7mmZGpfqnK7uC+gkN1TA/fhTFF+Ni8eOjwedPXsgLeSEvDPLCIC8M8sIgL+SFvJAX8kJeGOSFQV4Y5IVBXsgLeSEv5IW8MMgLow1e1i4XfH/kJR8deSEvcl48eSEvAC+RvJAXgJedvJAXOS9DR17Ii5yXSF7IC8DLTl7Ii5yX0JEX8iLnZSUv5EXOy7Nsl7yQF6h7IS/kBcheyAt5eYx+Jy/kRc7L0pEX8iLmZezIC3kR8zJ05IW8iHnxO3khL2JeDnAhL+Tlj8HoABfyQl6kqS55IS9/rrssHXkhL1Jewt6RF/Ii5GVYO4vYctouxGVLe2cXXvHg3TeN3eeu6rR9lRafl5ewGr3I6RHEOXXmMSse/PeSwTV7Vac9V2nxSXkZotmnv/ffvulYAZZ//h8HP/f+e0tC9qpK2+01WnxSXtZq372bu1oxwc/9u+mesld12lOVFp+Ul65SXtHHrl5s8HNfs+9vNdHeqrT4/rz8/kxC6mrGUJiR/hwfvIn2UKXFDfAyIhlgWSyFGenyopWo9lKlxffn5f9s122VcUHzx4casCF7VaXt9hotboCX+OsJpq56ROipj9mRczTRjlVa3AAvTmhym0QqykjHl3kqpp2qtPj+vKxY/1waoSAj/TlyDibaoUqLG+AlvG8w+h1PTUY6H+SpiPZapcX35yX18sWIN5tIDz2eP+oH5dq+Sosb4GV6z0RaY8lM2Q99MtGeq7S4AV4cOJqbm1XyjDQc5qli7X6v0uL787J8PfHv6sVobh3h2mOVFjfAi4fWIt5qIq3ZhZDVRHur0uL787J95auPTmAiPSwHOckikUx7qNLiBngZ35zsApZMzP5VNNFeqrT4/rz8zOTe3L3ILBnIOgK14aVJ3ES6Jy/z+7OX3+bwmHXUy/JUifZUpcUN8OIhJ+WtJhJmHWHaqUqL78/Lqkr+3mIi+ezI6U20Q5UWN8BL+ES2K7Nk5uzIOZtor1VafH9e/rOO0vt56RyakXp5nnqoXaXFDfAyfWLx5fe1N3lGugF5agQn6jYtboCXt1tHj664NCMdgZ7wQFvpfaS+dV6Wr8/MpgWWzJB9WYOJ9lilxQ3wMujWOt9hIi3ZwWAx0d6qtPj+vGyFz89k6UeY7TpsVdYbFUrJVS+wfxrBp2DxalIUf0gwXMytI5n2Ujp+t87LbrsQLk0TXlkye3adSG76vNAuqGqHTKT78vL6L3stL4cvZpIXSvXoPG4ytI503w55QeNoLTaJh7IJzrOSoXWkM5E4HqFxmFgO5tbRsXaZVzaQl2r57rFNswo7pkXhcq2G1pHKRLovL2Xz6T1tSwxOZQM7WaGUhwv6n2qXeh+OvNis16V5wBfeo6xQSrUqGw2tI42JdF9erPyAFB2onLdkZIVSq0b7kOBN1eK2eDH0G2eH9f5BkJHm99jvXqN9eKuDRrUxXkzrGWKPDHWr2jqKKu2jTmlRqTbGi229VArI7NVrC6W8Rlsww1eoNseLcT3mDKA4H2ZT69OruLZkBRFXbY4X63rvzYlX3x93ssv22AeNdi9xKPAWN8eLeQFvcmoTSWYd/XsV1j5EwZXZXs3wYl5ht3vpELAdZKTTi6uo9iYaalDVBnmxr/j+Zf2DJpLPLqjmr6LawlRWbXu1w0uFHUi/hiSsbEpWKLWotBdhx1FS6NUILxW2lGzS6mr3KiMdnl9FtQ/vcdSotslLjT0CMzApwayjDZrwwFO13iTjvTcvNc4jC7iJJLOORo1BBZifOturKV5qbFr777ECRo/QOurlC7ZBfoNeo9osLzU23Ue0bEp2PPOsKslCire0hV4t8VJjG5LDvmyxdfSF9xpQnwH0Re3yUuE8+BkzkWTHM6/Q0vSsKj43MJFuz0uN35tw0MxEbh3Bsx5wzmNgIt2flwq/ZxNlII7ZbDe/x/7b5ESoDW6eE6o2zov9kJSQlVXZ8cwRrD7eVGu20rXgtnmx/z2+QebcDLn1V/f19CriCg3SfwSrkpdatVOSzxuzjuTzukXVXRSbSI3wYvx7wklmyfydPz6svw7ZVdnhcPtJThtPRwSq5OXnVMLUS3LS6cmYJW18Oe2VaiumO8UmUjO8/J0zGA5KQbj80cv22E+KITT1muWUY1Xy8j8x0WpUisLl1Sk7wfWvp71C7cMO02tUA3n5Y4YwmyCzCC2ZlP3kZ9G66pH20dCymp4W0Cgv//QyIS5bKlvE25T+t3++897cWw86VUde8OgnoS+TFJhNwlWysp4wKVUjedHEa2B2XQXfUaGUZXVgVKq+znjJy7MeRvY/O/wHWQfpmkeRU/r0FMMyE+navPQf5wU6ZubZHvtnUXKEzaJWXa/MS61T6KzGI2jXrc9aR77Kjt5Br+ovzEu1U+iM8l2kgO/5Hnv74sCtQHW+MC8fOtUdeB3yk29D1joK6k5O2/OWlE2dnZflnLwsgCXzZ58UhNNeTBvyDUtMpLPzEs/JS1TUSrzaY29dhzEXqW7X5SWck5eAWDKwdQRrQylr0d77s/PizsmLw3Os/PHMS5X8bStUXS7Ly0d+tRNca5edoft6j/2z0P1q2lio+rzXOz0v8xl5mfGs9GCPvWnGe1gld6gaL8vLcEZeBjwpx6yjsoQ/Fqumy/JyxgEp4UkWaB2VJXCuXDVclpcTzqgjWoQk2WP/LPCfHlkNVNfL8nLCGZLDZ/2odVSyohAMVHd/VV7Ol/E+9gqHpdcpuxAvOoUdPvNIdO5Pr9x7fwFe3Om7F6ElA1lHehNpMlF9klpdgJezZTBRw/SIWkf678XZqI6X5aU/1RQp391LtqauAvDKPdfFSHW7LC/nMpGC1pIBrSOtieStVIfL8nKmlHdWWzJR2RFgJtJmprpcl5fzlE1takvGJ8n3W2wijWaq2f7vIry4k6QwyaktmUXdESAm0t7bqU7X5aXGKXQaI8/ZjZnyjgDRng1V04V5qXAKnQIXb1fatCOV6nJtb6kaLszLCYak5AyNHqQjkGuvpqrrlXmxP4UOTXWd5azfQ/cu1Q6mqpnh90K8fHhafdghQMuKG3bnQu3U26rGa/NifAodNBYJvlzE6Angncu0J2PVxyTrWrwYn0IHeEaSDxcwenZ0X6ZM21mrjhfnxfYUOvFQJHwPcqMnwvct0V7MVbfL82J5Cp1sJIrir1Zca7w7+K4l2oO9qr8+L19mp9AJYJmhdyCdwa2Kez7W3iqozrfg5cvmFLpXPUDalhjQbkBq9ATFDR9rjxVUv/eEl+WF8ZEgLwzywiAvDPLC509eyAt5IS8M8sIgLwzywiAv5IW8kBfyQl4Y5IVBXhjkhUFeyAt5IS/khbwwyAuDvDDIC+OWvPwFgd7gz8BmAQA="));
 
@@ -77,7 +77,7 @@ tmr = sys.nanoTime();
 while (sys.nanoTime() - tmr < 2147483648) sys.spin();
 // clear screen
 graphics.clearPixels(255);con.color_pair(239,255);
-con.clear();con.move(1,1);
+con.clear();con.move(1,1);graphics.resetPalette();
 
 ///////////////////////////////////////////////////////////////////////////////
 

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",
-    PATHEXT: ".com;.bat;.app;.js",
+    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
         }
@@ -423,11 +427,11 @@ _TVDOS.DRV.FS.SERIAL.sread = (fd) => {
 }
 _TVDOS.DRV.FS.SERIAL.bread = (fd) => {
     let str = _TVDOS.DRV.FS.SERIAL.sread(fd)
-    let bytes = new Int8Array(str.length)
+    let bytes = []//new Int8Array(str.length)
     for (let i = 0; i < str.length; i++) {
 //        let p = str.charCodeAt(i)
 //        bytes[i] = (p > 127) ? p - 255 : p
-        bytes[i] = str.charCodeAt(i)
+        bytes.push(str.charCodeAt(i))
     }
     return bytes
 }
@@ -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!
@@ -753,6 +839,34 @@ shell.execute = function(line) {
                         shell.execute(line)
                     })
                 }
+                else if ("ALIAS" == extension) {
+                    // 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, quoteAliasArg(tokens[j]))
+                        }
+
+                        // replace $0
+                        newLine = newLine.replaceAll('$0', tokens.slice(1).map(quoteAliasArg).join(' '))
+
+                        shell.execute(newLine, cmd)
+                    })
+                }
                 else if ("APP" == extension) {
                     let appexec = `A:${_TVDOS.variables.DOSDIR}\\sbin\\appexec.js`
                     let foundFile = searchFile.fullPath
@@ -767,6 +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)
@@ -806,6 +924,9 @@ shell.execute = function(line) {
                         continue
                     }
                 }
+                } finally {
+                    shell.runningScriptPaths.pop()
+                }
             }
         }
 
@@ -865,6 +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
@@ -909,23 +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)
@@ -941,32 +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/microtone.alias

@@ -0,0 +1 @@
+taut $0

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

@@ -1,112 +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()
-const TAD_INPUT_ADDR = SND_MEM_ADDR - 262144  // TAD input buffer (matches TAV packet 0x24)
-const TAD_DECODED_ADDR = SND_MEM_ADDR - 262144 + 65536  // 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) {
@@ -114,12 +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
@@ -133,148 +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) {
@@ -282,80 +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/playtav.js

@@ -158,9 +158,6 @@ audio.purgeQueue(AUDIO_DEVICE)
 audio.setPcmMode(AUDIO_DEVICE)
 audio.setMasterVolume(AUDIO_DEVICE, 255)
 
-// set colour zero as half-opaque black
-graphics.setPalette(0, 0, 0, 0, 7)
-
 // Parse SSF-TC subtitle packet and add to event buffer (0x31)
 function parseSubtitlePacketTC(packetSize) {
     // Read subtitle index (24-bit, little-endian)
@@ -1749,7 +1746,9 @@ try {
                     tadInitialised = true
                 }
 
-                seqread.readBytes(payloadLen, SND_MEM_ADDR - 262144)
+                // tadInputBin lives at audio-local offset 917504 (post-bef85f6 memory map);
+                // the previous 262144 offset now points into the enlarged sampleBin.
+                seqread.readBytes(payloadLen, SND_MEM_ADDR - 917504)
                 audio.tadDecode()
                 audio.tadUploadDecoded(AUDIO_DEVICE, sampleLen)
             }
@@ -2463,6 +2462,6 @@ finally {
     audio.purgeQueue(AUDIO_DEVICE)
 }
 
-graphics.setPalette(0, 0, 0, 0, 0)
+graphics.resetPalette()
 con.move(cy, cx) // restore cursor
 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_fileop.js

@@ -0,0 +1,77 @@
+/**
+ * TAUT File Operations
+ * Sub-program launched by taut.js when the File tab is active.
+ * 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.
+ *
+ * Created by minjaesong on 2026-04-27
+ */
+
+const win = require("wintex")
+
+const PANEL_COUNT = 7
+const MY_PANEL   = 6 // VIEW_FILE
+
+const [SCRH, SCRW] = con.getmaxyx()
+const PANEL_Y = 4
+const PANEL_H = SCRH - PANEL_Y
+
+const colStatus  = 253
+const colContent = 240
+const colHdr     = 230
+
+function drawFileOpContents(wo) {
+    for (let y = PANEL_Y; y < SCRH; y++) {
+        con.move(y, 1)
+        con.color_pair(colContent, 255)
+        print(' '.repeat(SCRW))
+    }
+    con.move(PANEL_Y + 1, 3)
+    con.color_pair(colHdr, 255)
+    print('[ File ]')
+    con.move(PANEL_Y + 3, 3)
+    con.color_pair(colStatus, 255)
+    print('placeholder — not yet implemented')
+}
+
+function drawHints() {
+    con.move(SCRH, 1)
+    con.color_pair(colStatus, 255)
+    print(' '.repeat(SCRW - 1))
+    con.move(SCRH, 1)
+    con.color_pair(colHdr, 255); print('Tab ')
+    con.color_pair(colStatus, 255); print('Panel')
+}
+
+function fileOpInput(wo, event) {
+    // placeholder — no interaction yet
+}
+
+const panel = new win.WindowObject(1, PANEL_Y, SCRW, PANEL_H, fileOpInput, drawFileOpContents, undefined, ()=>{})
+
+panel.drawContents()
+drawHints()
+
+let done = false
+while (!done) {
+    input.withEvent(event => {
+        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
+            done = true
+            return
+        }
+
+        panel.processInput(event)
+    })
+}
+
+return 0

assets/disk0/tvdos/bin/taut_helpmsg.js

@@ -0,0 +1,171 @@
+if (!_G.TAUT) _G.TAUT = {};
+let help = {}
+
+let ts = require("typesetter")
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+/*
+Tags:
+<b> - print the text in emphasis colour (colVoiceHdr aka 230)
+<c> - centre the line. If the line spans multiple lines, centre each line
+<r> - align right
+<l> - align left
+<o> - create virtual typesetting box. Left anchor: where the text cursor is. Right anchor: end of the line
+&microtone; - replace with the brand string (<col 211>Micro</col><col 239>tone</col>)
+
+&bul; - replace with bullet (\u00F9)
+&ddot; - replace with double-dot (\u008419u)
+&mdot; - replace with BIGDOT (\u00FA)
+&updn; - up-down arrow (\u008418u)
+&udlr; - four direction arrow (\u008428u\u008429u)
+
+&keyoffsym; - pattern view key-off symbol (\u00A0\u00B1\u00B1\u00A1)
+&notecutsym; - pattern view note-cut symbol (\u00A4\u00A4\u00A4\u00A4)
+
+&demisharp;
+&sharp;
+&sesquisharp;
+&doublesharp;
+&triplesharp;
+&quadsharp;
+&demiflat;
+&flat;
+&sesquiflat;
+&doubleflat;
+&tripleflat;
+&quadflat;
+&accuptick;
+&accdntick;
+&accupup;
+&accdndn;
+
+&nbsp; - nonbreakable space (only meaningful for typesetters)
+&shy; - soft hyphen (only meaningful for typesetters)
+
+default alignment: fully justified
+ */
+
+let helpNotation = `<c>CONTROL NOTATION</c>
+<c>\u00B7${'\u00B8'.repeat(16)}\u00B9</c>
+&microtone; <O>shortcuts differentiate normal and shifted shortcuts.</O>
+&bul;<b>a</b>&ddot;<b>z</b> : <O>alphabet without shift-in</O>
+&bul;<b>A</b>&ddot;<b>Z</b> : <O>alphabet with shift-in</O>
+&bul;<b>^q</b> : <O>hit 'q' with control key</O>
+&bul;<b>^Q</b> : <O>hit 'q' with control and shift key</O>
+`
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+let helpJam = `<c>NOTE JAMMING</c>
+<c>\u00B7${'\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
+`
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+let helpCommon = `<c>COMMON CONTROLS</c>
+<c>\u00B7${'\u00B8'.repeat(15)}\u00B9</c>
+&bul;<b>!</b> : <O>show this help message</O>
+&bul;<b>Y</b> : <O>plays the entire song from the current cue</O>
+&bul;<b>U</b> : <O>plays the current cue then stop</O>
+&bul;<b>I</b> : <O>plays the current row</O>
+&bul;<b>O</b> : <O>stops the playback</O>
+&bul;<b>tab</b> : <O>switchs forward a tab</O>
+&bul;<b>TAB</b> : <O>switchs backward a tab</O>
+&bul;<b>q</b> : <O>closes &microtone;</O>
+`
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+let helpTimeline = `<c>TIMELINE VIEW</c>
+<c>\u00B7${'\u00B8'.repeat(13)}\u00B9</c>
+Timeline has two distinct modes: view and edit mode. Two modes are toggled using the space bar.
+
+<b>&nbsp;VIEW MODE</b>
+<b>\u00B7${'\u00B8'.repeat(9)}\u00B9</b>
+&bul;Note jamming : <O>plays the note</O>
+&bul;<b>&udlr;</b> : <O>moves the viewing cursor by voices and rows</O>
+&bul;<b>pg&updn;</b> : <O>goes to previous/next cue</O>
+&bul;<b>W</b>&mdot;<b>E</b>&mdot;<b>R</b> : <O>toggles timeline view mode. W-most detailed, R-most abridged</O>
+&bul;<b>n</b> : <O>toggles soloing of the selected voice</O>
+&bul;<b>m</b> : <O>toggles muting of the selected voice</O>
+&bul;<b>[</b>&mdot;<b>]</b> : <O>changes tick rate of playhead</O>
+
+<b>&nbsp;EDIT MODE</b>
+<b>\u00B7${'\u00B8'.repeat(9)}\u00B9</b>
+&bul;Note jamming : <O>(note column) inserts the note</O>
+&bul;<b>{</b>&mdot;<b>}</b> : <O>(note column) 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>moves the viewing cursor by columns and rows</O>
+&bul;<b>pg&updn;</b> : <O>goes to previous/next cue</O>
+
+<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 HRULE = '\u00B4\u00B5'.repeat((_G.TAUT.HELPMSG_WIDTH) >>> 1) + '\n'
+
+// 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
+    /* 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    = ts.COL_TEXT
+help.COL_EMPH    = ts.COL_EMPH
+
+if (!_G.TAUT.HELPMSG) _G.TAUT.HELPMSG=help;

assets/disk0/tvdos/bin/taut_instredit.js

@@ -0,0 +1,77 @@
+/**
+ * TAUT Instrument Editor
+ * Sub-program launched by taut.js when the Instrmnt tab is active.
+ * 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.
+ *
+ * Created by minjaesong on 2026-04-27
+ */
+
+const win = require("wintex")
+
+const PANEL_COUNT = 7
+const MY_PANEL   = 4 // VIEW_INSTRMNT
+
+const [SCRH, SCRW] = con.getmaxyx()
+const PANEL_Y = 4
+const PANEL_H = SCRH - PANEL_Y
+
+const colStatus  = 253
+const colContent = 240
+const colHdr     = 230
+
+function drawInstEditContents(wo) {
+    for (let y = PANEL_Y; y < SCRH; y++) {
+        con.move(y, 1)
+        con.color_pair(colContent, 255)
+        print(' '.repeat(SCRW))
+    }
+    con.move(PANEL_Y + 1, 3)
+    con.color_pair(colHdr, 255)
+    print('[ Instrument Editor ]')
+    con.move(PANEL_Y + 3, 3)
+    con.color_pair(colStatus, 255)
+    print('placeholder — not yet implemented')
+}
+
+function drawHints() {
+    con.move(SCRH, 1)
+    con.color_pair(colStatus, 255)
+    print(' '.repeat(SCRW - 1))
+    con.move(SCRH, 1)
+    con.color_pair(colHdr, 255); print('Tab ')
+    con.color_pair(colStatus, 255); print('Panel')
+}
+
+function instEditInput(wo, event) {
+    // placeholder — no interaction yet
+}
+
+const panel = new win.WindowObject(1, PANEL_Y, SCRW, PANEL_H, instEditInput, drawInstEditContents, undefined, ()=>{})
+
+panel.drawContents()
+drawHints()
+
+let done = false
+while (!done) {
+    input.withEvent(event => {
+        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
+            done = true
+            return
+        }
+
+        panel.processInput(event)
+    })
+}
+
+return 0

assets/disk0/tvdos/bin/taut_sampleedit.js

@@ -0,0 +1,181 @@
+/**
+ * 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
+ *   [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 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
+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
+
+// 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, colBack)
+        print(' '.repeat(SCRW))
+    }
+    // Title
+    con.move(PANEL_Y + 1, 3)
+    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, colBack)
+    print(' '.repeat(SCRW - 1))
+    con.move(SCRH, 1)
+    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) {
+    // wintex panel input — wired up but the loop below handles keys directly.
+}
+
+function drawAll() {
+    drawSampleEditFrame()
+    drawToolList()
+    drawHints()
+}
+
+const panel = new win.WindowObject(1, PANEL_Y, SCRW, PANEL_H, sampleEditInput, drawAll, undefined, ()=>{})
+
+panel.drawContents()
+
+let done = false
+while (!done) {
+    input.withEvent(event => {
+        if (event[0] !== 'key_down') return
+        const keysym     = event[1]
+        const keyJustHit = (1 == event[2])
+
+        if (!keyJustHit) return
+
+        if (keysym === '<ESCAPE>' || keysym === '<TAB>') {
+            _G.TAUT.UI.NEXTPANEL = PARENT_PANEL
+            done = true
+            return
+        }
+
+        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
+            }
+        }
+    })
+}
+
+return 0

assets/disk0/tvdos/bin/tautbtn.r8

@@ -0,0 +1 @@
+<EFBFBD><EFBFBD>洄洄洄洄洄泚<EFBFBD>泚<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>_<EFBFBD>_

assets/disk0/tvdos/bin/tautbtn0.r8

@@ -0,0 +1 @@
+<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD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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/gl.mjs

@@ -45,7 +45,7 @@ exports.SpriteSheet = function(tilew, tileh, tex) {
         return ty;
     };
 };
-exports.drawTexPattern = function(texture, x, y, width, height, framebuffer, fgcol, bgcol) {
+exports.drawTexPattern = function(texture, x, y, width = texture.width, height = texture.height, framebuffer = false, fgcol, bgcol) {
     if (!(texture instanceof exports.Texture) && !(texture instanceof exports.MonoTex)) throw Error("Texture is not a GL Texture types");
 
     let paint = (!framebuffer) ? graphics.plotPixel : graphics.plotPixel2

assets/disk0/tvdos/include/keysym.mjs

@@ -0,0 +1,80 @@
+/**
+ * These are key symbols returned by `input.withEvent`, NOT `con.getch()`
+ */
+
+exports = {
+NUM_0:7,
+NUM_1:8,
+NUM_2:9,
+NUM_3:10,
+NUM_4:11,
+NUM_5:12,
+NUM_6:13,
+NUM_7:14,
+NUM_8:15,
+NUM_9:16,
+A:29,
+ALT_LEFT:57,
+ALT_RIGHT:58,
+APOSTROPHE:75,
+AT:77,
+B:30,
+BACK:4,
+BACKSLASH:73,
+C:31,
+CAPS_LOCK:115,
+COMMA:55,
+D:32,
+DEL:67,
+BACKSPACE:67,
+FORWARD_DEL:112,
+DOWN:20,
+LEFT:21,
+RIGHT:22,
+UP:19,
+E:33,
+ENTER:66,
+EQUALS:70,
+F:34,
+G:35,
+GRAVE:68,
+H:36,
+HOME:3,
+I:37,
+J:38,
+K:39,
+L:40,
+LEFT_BRACKET:71,
+M:41,
+MINUS:69,
+N:42,
+O:43,
+P:44,
+PERIOD:56,
+PLUS:81,
+Q:45,
+R:46,
+RIGHT_BRACKET:72,
+S:47,
+SEMICOLON:74,
+SHIFT_LEFT:59,
+SHIFT_RIGHT:60,
+SLASH:76,
+SPACE:62,
+SYM:63, // on MacOS, this is Command (⌘)
+T:48,
+TAB:61,
+U:49,
+V:50,
+W:51,
+X:52,
+Y:53,
+Z:54,
+CONTROL_LEFT:129,
+CONTROL_RIGHT:130,
+ESCAPE:111,
+END:123,
+INSERT:124,
+PAGE_UP:92,
+PAGE_DOWN:93,
+}

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

@@ -8,16 +8,24 @@
 
 const TAUD_MAGIC        = [0x1F,0x54,0x53,0x56,0x4D,0x61,0x75,0x64]  // \x1F TSVMaud
 const TAUD_VERSION      = 1
-const TAUD_HEADER_SIZE  = 32     // magic(8) + version(1) + numSongs(1) + compSize(4) + rsvd(2) + sig(16)
-const TAUD_SONG_ENTRY   = 16     // bytes per song-table row (offset(4)+voices(1)+pats(2)+bpm(1)+tick(1)+pad(7))
-const SAMPLEINST_SIZE   = 786432 // 770047 sample + 16384 instrument
+const TAUD_HEADER_SIZE  = 32     // magic(8) + version(1) + numSongs(1) + compSize(4) + projOff(4) + sig(14)
+const TAUD_SONG_ENTRY   = 32     // see encodeSongEntry / decodeSongEntry below
+// Sample+instrument image: 8 MB sample pool (banked, 16 × 512 K) + 64 K instrument bin = 8256 kB total.
+// (terranmon.txt:1985-1997, 2533-2564 — bank-switched via MMIO 46.)
+const SAMPLE_BANK_SIZE  = 524288             // 512 K — size of the sample-bin window
+const SAMPLE_BANK_COUNT = 16                 // 16 banks × 512 K = 8 MB
+const SAMPLEBIN_SIZE    = SAMPLE_BANK_SIZE * SAMPLE_BANK_COUNT   // 8 MB
+const INSTBIN_SIZE      = 65536              // 256 inst × 256 bytes
+const SAMPLEINST_SIZE   = SAMPLEBIN_SIZE + INSTBIN_SIZE          // 8454144 = 8256 kB
+const SAMPLEBIN_WINDOW_OFFSET = 0            // peripheral memory window for the active sample bank
+const INSTBIN_WINDOW_OFFSET   = 720896       // peripheral memory offset of instrument bin
 const PATTERN_SIZE      = 512    // bytes per pattern (64 rows × 8 bytes)
 const NUM_PATTERNS_MAX  = 256
 const NUM_CUES          = 1024
 const CUE_SIZE          = 32     // bytes per cue entry (packed 12-bit×20 voices + instruction + pad)
 
-// Signature written into the file (16 bytes, space-padded)
-const CAPTURE_SIGNATURE = "LibTaud/TSVM    "
+// Signature written into the file (14 bytes, space-padded)
+const CAPTURE_SIGNATURE = "LibTaud/TSVM  "
 
 // ── Internal helpers ────────────────────────────────────────────────────────
 
@@ -43,9 +51,9 @@ function _pokeU32LE(ptr, off, v) {
  *
  * @param inFile             Full path with drive letter, e.g. "A:/music/song.taud"
  * @param songIndex          0-based index of the song in the SONG TABLE
- * @param targetPlaydataSlot Playhead number (0-3) to configure
+ * @param playhead Playhead number (0-3) to configure
  */
-function uploadTaudFile(inFile, songIndex, targetPlaydataSlot) {
+function uploadTaudFile(inFile, songIndex, playhead) {
     const drive    = inFile[0].toUpperCase()
     const diskPath = inFile.substring(2)
 
@@ -75,11 +83,13 @@ function uploadTaudFile(inFile, songIndex, targetPlaydataSlot) {
     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) {
@@ -88,17 +98,14 @@ function uploadTaudFile(inFile, songIndex, targetPlaydataSlot) {
     }
 
     // -- 4. Decompress and upload sample+instrument bin -----------------------
-    let decompPtr = sys.malloc(SAMPLEINST_SIZE)
-    gzip.decompFromTo(filePtr + pos, compressedSize, decompPtr)
+    // The decompressed image is 8256 kB (8 MB samples bank-major + 64 K instruments)
+    // which exceeds the 8 MB user-space cap, so we route through a hardware helper
+    // that decompresses straight into the adapter's native sample/instrument
+    // storage instead of staging a buffer in user memory.
+    audio.uploadSampleInstBlob(filePtr + pos, compressedSize)
+    audio.setSampleBank(0)
     pos += compressedSize
 
-    // Write decompressed data to peripheral memory (backwards addressing:
-    // peripheral byte k lives at memBase - k).
-    for (let i = 0; i < SAMPLEINST_SIZE; i++) {
-        sys.poke(memBase - i, sys.peek(decompPtr + i))
-    }
-    sys.free(decompPtr)
-
     // -- 5. Parse song-table entry for the requested song --------------------
     let entryOff   = pos + songIndex * TAUD_SONG_ENTRY
     let songOffset = _peekU32LE(filePtr, entryOff)
@@ -107,32 +114,92 @@ function uploadTaudFile(inFile, songIndex, targetPlaydataSlot) {
     let numPatsHi  = sys.peek(filePtr + entryOff + 6) & 0xFF
     let bpmStored  = sys.peek(filePtr + entryOff + 7) & 0xFF
     let tickRate   = sys.peek(filePtr + entryOff + 8) & 0xFF
+    let mixerflags = sys.peek(filePtr + entryOff + 15) & 0xFF
+    let songGlobalVolume = sys.peek(filePtr + entryOff + 16) & 0xFF
+    let songMixingVolume = sys.peek(filePtr + entryOff + 17) & 0xFF
+    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. Upload patterns ---------------------------------------------------
-    let songBase  = filePtr + songOffset
-    let patBytes  = new Array(PATTERN_SIZE)
+    // -- 6. Decompress + upload patterns --------------------------------------
+    let patBinSize  = patsToLoad * PATTERN_SIZE
+    let patBinPtr   = sys.malloc(patBinSize)
+    gzip.decompFromTo(filePtr + songOffset, patBinCompSize, patBinPtr)
+
+    let patBytes = new Array(PATTERN_SIZE)
     for (let p = 0; p < patsToLoad; p++) {
         for (let k = 0; k < PATTERN_SIZE; k++)
-            patBytes[k] = sys.peek(songBase + p * PATTERN_SIZE + k) & 0xFF
+            patBytes[k] = sys.peek(patBinPtr + p * PATTERN_SIZE + k) & 0xFF
         audio.uploadPattern(p, patBytes)
     }
+    sys.free(patBinPtr)
+
+    // -- 7. Decompress + upload cue sheet -------------------------------------
+    let cueSheetSize = NUM_CUES * CUE_SIZE
+    let cueSheetPtr  = sys.malloc(cueSheetSize)
+    gzip.decompFromTo(filePtr + songOffset + patBinCompSize, cueSheetCompSize, cueSheetPtr)
 
-    // -- 7. Upload cue sheet --------------------------------------------------
-    let cueBase  = songBase + patsToLoad * PATTERN_SIZE
     let cueBytes = new Array(CUE_SIZE)
     for (let c = 0; c < NUM_CUES; c++) {
         for (let k = 0; k < CUE_SIZE; k++)
-            cueBytes[k] = sys.peek(cueBase + c * CUE_SIZE + k) & 0xFF
+            cueBytes[k] = sys.peek(cueSheetPtr + c * CUE_SIZE + k) & 0xFF
         audio.uploadCue(c, cueBytes)
     }
+    sys.free(cueSheetPtr)
 
     // -- 8. Configure playhead ------------------------------------------------
-    audio.setTrackerMode(targetPlaydataSlot)
-    audio.setBPM(targetPlaydataSlot, bpm)
-    audio.setTickRate(targetPlaydataSlot, tickRate > 0 ? tickRate : 6)
+    audio.setTrackerMode(playhead)
+    audio.setBPM(playhead, bpm)
+    audio.setTickRate(playhead, tickRate > 0 ? tickRate : 6)
+    audio.setTrackerMixerFlags(playhead, mixerflags)
+    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()
@@ -156,14 +223,19 @@ function captureTrackerDataToFile(outFile) {
     const baseAddr = audio.getBaseAddr()
 
     // -- 1. Compress sample+instrument bin ------------------------------------
-    // sys.memcpy(negative_src, positive_dst, len) copies peripheral byte k from
-    // (memBase - k) into (sampleInstBuf + k).
-    let sampleInstBuf = sys.malloc(SAMPLEINST_SIZE)
-    sys.memcpy(memBase, sampleInstBuf, SAMPLEINST_SIZE)
-
-    let compBuf       = sys.malloc(SAMPLEINST_SIZE + 4096)  // headroom for incompressible data
-    let compressedSize = gzip.compFromTo(sampleInstBuf, SAMPLEINST_SIZE, compBuf)
-    sys.free(sampleInstBuf)
+    // The 8256 kB raw image (8 MB samples + 64 K instruments) cannot fit in the
+    // 8 MB user space, so we hand the entire compress step to a hardware helper
+    // that reads directly out of the adapter's native sample/instrument storage.
+    // Realistic sample data compresses well under both gzip and zstd; we cap the
+    // destination at "uncompressed size + 8 K" headroom which suffices for any
+    // sane musical content.
+    const COMP_BUF_CAP = 1024 * 1024 * 4   // 4 MiB cap for compressed sample+inst blob
+    let compBuf       = sys.malloc(COMP_BUF_CAP)
+    let compressedSize = audio.captureSampleInstBlob(compBuf, COMP_BUF_CAP)
+    if (compressedSize > COMP_BUF_CAP) {
+        sys.free(compBuf)
+        throw Error("taud: compressed sample+inst blob exceeded " + COMP_BUF_CAP + " bytes (got " + compressedSize + ")")
+    }
 
     // -- 2. Find last non-empty pattern in bank 0 (all-zero = uninitialized) --
     let numPatsActual = 0
@@ -181,18 +253,47 @@ function captureTrackerDataToFile(outFile) {
     let numPats    = numPatsActual  // Uint16, 1-65535
     let patsToSave = numPatsActual
 
-    // -- 3. BPM / tick-rate from playhead 0 -----------------------------------
+    // -- 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
+    if (songMixingVolume === undefined || songMixingVolume === null) songMixingVolume = 0x80
 
-    // -- 4. Compute song offset (absolute from file start) --------------------
+    // -- 4. Compress pattern bin ----------------------------------------------
+    let patBinSize = patsToSave * PATTERN_SIZE
+    let patBuf     = sys.malloc(patBinSize)
+    sys.memcpy(memBase - 131072, patBuf, patBinSize)
+
+    let patCompBuf = sys.malloc(patBinSize + 4096)
+    let patCompSize = gzip.compFromTo(patBuf, patBinSize, patCompBuf)
+    sys.free(patBuf)
+
+    // -- 5. Compress cue sheet ------------------------------------------------
+    // Cue entry c, byte k is at MMIO address 32768 + c*32 + k,
+    // accessed as sys.peek(baseAddr − (32768 + c*32 + k)).
+    let cueSheetSize = NUM_CUES * CUE_SIZE
+    let cueBuf = sys.malloc(cueSheetSize)
+    for (let c = 0; c < NUM_CUES; c++) {
+        let cueOff = 32768 + c * CUE_SIZE
+        for (let k = 0; k < CUE_SIZE; k++)
+            sys.poke(cueBuf + c * CUE_SIZE + k,
+                sys.peek(baseAddr - (cueOff + k)) & 0xFF)
+    }
+
+    let cueCompBuf  = sys.malloc(cueSheetSize + 4096)
+    let cueCompSize = gzip.compFromTo(cueBuf, cueSheetSize, cueCompBuf)
+    sys.free(cueBuf)
+
+    // -- 6. Compute song offset (absolute from file start) --------------------
     // Layout: header(32) + compressed(compressedSize) + songTable(1 × TAUD_SONG_ENTRY)
     let songOffset = TAUD_HEADER_SIZE + compressedSize + 1 * TAUD_SONG_ENTRY
 
-    // -- 5. Build header byte array (32 bytes) --------------------------------
-    let sigBytes = new Array(16)
-    for (let i = 0; i < 16; i++)
+    // -- 7. Build header byte array (32 bytes) --------------------------------
+    let sigBytes = new Array(14)
+    for (let i = 0; i < 14; i++)
         sigBytes[i] = i < CAPTURE_SIGNATURE.length ? CAPTURE_SIGNATURE.charCodeAt(i) : 0
 
     let header = [
@@ -200,16 +301,16 @@ function captureTrackerDataToFile(outFile) {
         0x1F, 0x54, 0x53, 0x56, 0x4D, 0x61, 0x75, 0x64,
         // version, numSongs
         TAUD_VERSION, 1,
-        // compressedSize uint32 LE (4)
+        // compressedSize uint32 LE (4) -- sample+inst bin
         (compressedSize        ) & 0xFF,
         (compressedSize >>>  8) & 0xFF,
         (compressedSize >>> 16) & 0xFF,
         (compressedSize >>> 24) & 0xFF,
-        // reserved (2)
-        0x00, 0x00,
-    ].concat(sigBytes)  // 8 + 2 + 4 + 2 + 16 = 32 bytes
+        // project data offset (4) -- not emitted
+        0x00, 0x00, 0x00, 0x00,
+    ].concat(sigBytes)  // 8 + 2 + 4 + 4 + 14 = 32 bytes
 
-    // -- 6. Build song-table row (16 bytes) -----------------------------------
+    // -- 8. Build song-table row (32 bytes) -----------------------------------
     let songTable = [
         (songOffset        ) & 0xFF,
         (songOffset >>>  8) & 0xFF,
@@ -217,40 +318,47 @@ 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
-        0,0,0,0,0,0,0,        // 7 bytes padding
+        0x00,0xA0,                             // basenote (0xA000 -- C9)
+        0x00,0xAC,0x02,0x46,                   // basefreq (8363 Hz)
+        sys.peek(baseAddr - 7),                // mixer flags
+        songGlobalVolume & 0xFF,               // global volume
+        songMixingVolume & 0xFF,               // mixing volume
+        // pattern bin compressed size (4)
+        (patCompSize        ) & 0xFF,
+        (patCompSize >>>  8) & 0xFF,
+        (patCompSize >>> 16) & 0xFF,
+        (patCompSize >>> 24) & 0xFF,
+        // cue sheet compressed size (4)
+        (cueCompSize        ) & 0xFF,
+        (cueCompSize >>>  8) & 0xFF,
+        (cueCompSize >>> 16) & 0xFF,
+        (cueCompSize >>> 24) & 0xFF,
+        // reserved (6)
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     ]
 
-    // -- 7. Write header (creates / truncates file) ---------------------------
+    // -- 9. Write header (creates / truncates file) ---------------------------
     const fileHandle = files.open(outFile)
     fileHandle.bwrite(header)
 
-    // -- 8. Append compressed sample+inst bin ---------------------------------
-    fileHandle.pwrite(compBuf, compressedSize, 32)
+    // -- 10. Append compressed sample+inst bin --------------------------------
+    fileHandle.pwrite(compBuf, compressedSize, TAUD_HEADER_SIZE)
     sys.free(compBuf)
 
-    // -- 9. Write song table --------------------------------------------------
+    // -- 11. Write song table -------------------------------------------------
     fileHandle.bwrite(songTable)
 
-    // -- 10. Append pattern bin -----------------------------------------------
-    let patBuf = sys.malloc(patsToSave * PATTERN_SIZE)
-    sys.memcpy(memBase - 131072, patBuf, patsToSave * PATTERN_SIZE)
-    fileHandle.pwrite(patBuf, patsToSave * PATTERN_SIZE, 32 + compressedSize + songTable.length)
-    sys.free(patBuf)
+    // -- 12. Append compressed pattern bin ------------------------------------
+    fileHandle.pwrite(patCompBuf, patCompSize,
+        TAUD_HEADER_SIZE + compressedSize + songTable.length)
+    sys.free(patCompBuf)
 
-    // -- 11. Append cue sheet (all 1024 entries from MMIO space) --------------
-    // Cue entry c, byte k is at MMIO address 32768 + c*32 + k,
-    // accessed as sys.peek(baseAddr − (32768 + c*32 + k)).
-    let cueBuf = sys.malloc(NUM_CUES * CUE_SIZE)
-    for (let c = 0; c < NUM_CUES; c++) {
-        let cueOff = 32768 + c * CUE_SIZE
-        for (let k = 0; k < CUE_SIZE; k++)
-            sys.poke(cueBuf + c * CUE_SIZE + k,
-                sys.peek(baseAddr - (cueOff + k)) & 0xFF)
-    }
-    fileHandle.pwrite(cueBuf, NUM_CUES * CUE_SIZE, 32 + compressedSize + songTable.length + patsToSave * PATTERN_SIZE)
-    sys.free(cueBuf)
+    // -- 13. Append compressed cue sheet --------------------------------------
+    fileHandle.pwrite(cueCompBuf, cueCompSize,
+        TAUD_HEADER_SIZE + compressedSize + songTable.length + patCompSize)
+    sys.free(cueCompBuf)
 
 
     fileHandle.flush(); fileHandle.close()

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`)
             }
 
 
@@ -96,8 +96,6 @@ class WindowObject {
  * @return [new cursor pos, new scroll pos]
  */
 function scrollVert(dy, listSize, listHeight, currentCursorPos, currentScrollPos, scrollPeek) {
-    let peek = 1
-
     // clamp dy
     if (currentCursorPos + dy > listSize - 1)
         dy = (listSize - 1) - currentCursorPos
@@ -108,13 +106,13 @@ function scrollVert(dy, listSize, listHeight, currentCursorPos, currentScrollPos
     
     // update vertical scroll stats
     if (dy != 0) {
-        let visible = listHeight - 1 - peek
+        let visible = listHeight - 1 - scrollPeek
 
         if (nextRow - currentScrollPos > visible) {
             currentScrollPos = nextRow - visible
         }
-        else if (nextRow - currentScrollPos < 0 + peek) {
-            currentScrollPos = nextRow - peek // nextRow is less than zero
+        else if (nextRow - currentScrollPos < 0 + scrollPeek) {
+            currentScrollPos = nextRow - scrollPeek // nextRow is less than zero
         }
 
         // NOTE: future-proofing here -- scroll clamping is moved outside of go-up/go-down
@@ -145,8 +143,6 @@ function scrollVert(dy, listSize, listHeight, currentCursorPos, currentScrollPos
  * @return [new cursor pos, new scroll pos]
  */
 function scrollHorz(dx, stringSize, stringViewSize, currentCursorPos, currentScrollPos, scrollPeek) {
-    let peek = 1
-
     // clamp dx
     if (currentCursorPos + dx > stringSize - 1)
         dx = (stringSize - 1) - currentCursorPos
@@ -157,13 +153,13 @@ function scrollHorz(dx, stringSize, stringViewSize, currentCursorPos, currentScr
 
     // update vertical scroll stats
     if (dx != 0) {
-        let visible = stringViewSize - 1 - peek
+        let visible = stringViewSize - 1 - scrollPeek
 
         if (nextCol - currentScrollPos > visible) {
             currentScrollPos = nextCol - visible
         }
-        else if (nextCol - currentScrollPos < 0 + peek) {
-            currentScrollPos = nextCol - peek // nextCol is less than zero
+        else if (nextCol - currentScrollPos < 0 + scrollPeek) {
+            currentScrollPos = nextCol - scrollPeek // nextCol is less than zero
         }
 
         // NOTE: future-proofing here -- scroll clamping is moved outside of go-up/go-down
@@ -184,4 +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

doc/implementation.tex

@@ -662,7 +662,7 @@ TODO
 \endlastfoot
 \centering
 \begin{tabulary}{\textwidth}{rl}
-{\ttfamily 0} & {\ttfamily \#000F} \\
+{\ttfamily 0} & {\ttfamily \#0007} \\
 {\ttfamily 1} & {\ttfamily \#004F} \\
 {\ttfamily 2} & {\ttfamily \#008F} \\
 {\ttfamily 3} & {\ttfamily \#00BF} \\

mod2taud.py

@@ -0,0 +1,995 @@
+#!/usr/bin/env python3
+"""mod2taud.py — Convert ProTracker (.mod) to TSVM Taud (.taud)
+
+Usage:
+    python3 mod2taud.py input.mod output.taud [-v]
+
+Limits:
+    - Up to 20 MOD channels (excess disabled; hard error if pattern count
+      × channel count > 4095).
+    - Sample bin is 8 MB (8388608 bytes); if all samples together exceed
+      this, every sample is globally resampled down (with c2spd adjusted)
+      so pitch is preserved.
+
+Effect support:
+    Full PT effect dispatch per TAUD_NOTE_EFFECTS.md "ProTracker to Taud
+    conversion table". PT recalls (effect $00 args) are eagerly resolved
+    per channel using PT's per-effect private memory model. Cxx folds
+    into the volume column (0.$xx). Axy / EAx / EBx fold into the volume
+    column. 8xx and E8x fold into the pan column. Periods convert to Taud
+    units via log2 against PT period 428 (≡ Taud C3). Sample finetune is
+    pre-baked into the per-instrument c2spd. Amiga-mode flag is set in
+    the song-table flags byte so the engine applies coarse pitch slides
+    in period space.
+"""
+
+import argparse
+import copy
+import math
+import struct
+import sys
+
+from taud_common import (
+    set_verbose, vprint,
+    TAUD_MAGIC, TAUD_VERSION, TAUD_HEADER_SIZE, TAUD_SONG_ENTRY,
+    SAMPLEBIN_SIZE, INSTBIN_SIZE, SAMPLEINST_SIZE,
+    PATTERN_ROWS, PATTERN_BYTES, NUM_PATTERNS_MAX, NUM_CUES, CUE_SIZE, NUM_VOICES,
+    NOTE_NOP, NOTE_KEYOFF, NOTE_CUT, TAUD_C4,
+    TOP_NONE, TOP_A, TOP_B, TOP_C, TOP_D, TOP_E, TOP_F, TOP_G, TOP_H, TOP_I,
+    TOP_J, TOP_K, TOP_L, TOP_O, TOP_Q, TOP_R, TOP_S, TOP_T, TOP_U, TOP_V, TOP_Y,
+    SEL_SET, SEL_UP, SEL_DOWN, SEL_FINE,
+    J_SEMI_TABLE,
+    d_arg_to_col, resample_linear, rescale_offset_effects, encode_cue, deduplicate_patterns,
+    encode_song_entry, compress_blob,
+    build_project_data, detect_subsongs,
+)
+
+
+# ── MOD constants ────────────────────────────────────────────────────────────
+
+MOD_NUM_SAMPLES = 31
+MOD_PATTERN_ROWS = 64
+
+# PT effect numbers (single hex digit 0..F). Effect $E uses sub-nibbles.
+PT_E_BASE = 0xE
+PT_F = 0xF
+
+# PT effects that have private memory and therefore recall their last
+# non-zero argument when re-issued with $00. Top-level effects:
+PT_MEM_TOP = frozenset({0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0xA})
+# E sub-effects with memory (key is sub-nibble of the E command):
+PT_MEM_E_SUB = frozenset({0x1, 0x2, 0xA, 0xB})
+
+GLOBAL_FLAGS_AMIGA_FREQ = 0b01
+GLOBAL_FLAGS_A500_INTP = 0b1000
+
+
+# ── Taud constants (mod-specific) ────────────────────────────────────────────
+
+SIGNATURE        = b"mod2taud/TSVM "    # 14 bytes
+
+# PT period 428 (PT "C-2") corresponds to OpenMPT/IT C-4 which s3m2taud
+# anchors to Taud C4 (0x5000). We use the same anchor so MOD/S3M imports
+# share a pitch reference.
+PT_REFERENCE_PERIOD = 428.0
+
+
+# ── MOD parser ───────────────────────────────────────────────────────────────
+
+class ModSample:
+    __slots__ = ('name','length','finetune','volume','loop_begin','loop_end',
+                 'sample_data','c2spd','flags')
+
+class ModRow:
+    __slots__ = ('period','inst','effect','effect_arg','vol_set')
+    def __init__(self):
+        self.period     = 0      # 0 = empty / no trigger
+        self.inst       = 0      # 0 = no instrument set
+        self.effect     = 0      # PT effect digit ($0..$F)
+        self.effect_arg = 0
+        # PT has no volume column; Cxx folds into vol_set during parsing.
+        # -1 = no explicit volume.
+        self.vol_set    = -1
+
+
+def _parse_magic(magic: bytes) -> int:
+    """Return number of channels declared by the 4-byte MOD magic."""
+    if magic in (b'M.K.', b'M!K!', b'FLT4', b'M&K!', b'N.T.'):
+        return 4
+    if magic == b'FLT8':
+        return 8
+    if magic == b'OCTA' or magic == b'CD81':
+        return 8
+    # xCHN (1..9 channels)
+    if len(magic) == 4 and magic[1:] == b'CHN' and 0x31 <= magic[0] <= 0x39:
+        return magic[0] - 0x30
+    # xxCH (10..32 channels)
+    if len(magic) == 4 and magic[2:] == b'CH' and magic[:2].isdigit():
+        return int(magic[:2].decode('ascii'))
+    # xxCN (e.g., 16CN — rare)
+    if len(magic) == 4 and magic[2:] == b'CN' and magic[:2].isdigit():
+        return int(magic[:2].decode('ascii'))
+    return 0
+
+
+def parse_mod(data: bytes):
+    if len(data) < 0x43C:
+        sys.exit("error: file too short to be a ProTracker module")
+
+    title = data[0x00:0x14].rstrip(b'\x00').decode('latin-1', errors='replace')
+
+    # 31 sample headers
+    samples = []
+    for i in range(MOD_NUM_SAMPLES):
+        base = 0x14 + i * 30
+        s = ModSample()
+        s.name        = data[base:base+22].rstrip(b'\x00').decode('latin-1', errors='replace')
+        s.length      = struct.unpack_from('>H', data, base + 22)[0] * 2
+        s.finetune    = data[base + 24] & 0x0F     # signed nibble 0..15
+        s.volume      = data[base + 25]            # 0..64
+        s.loop_begin  = struct.unpack_from('>H', data, base + 26)[0] * 2
+        loop_len_w    = struct.unpack_from('>H', data, base + 28)[0]
+        loop_len      = loop_len_w * 2
+        s.loop_end    = s.loop_begin + loop_len
+        # Flag bit 0 = looped (loop_len > 2 by convention; loop_len_w == 1 means no loop)
+        s.flags       = 1 if loop_len_w > 1 else 0
+        if not s.flags:
+            s.loop_begin = 0
+            s.loop_end   = 0
+        s.sample_data = b''
+        s.c2spd       = round(8363.0 * (2.0 ** (_signed4(s.finetune) / 96.0)))
+        samples.append(s)
+
+    song_length = data[0x3B6]
+    # 0x3B7 = restart byte (unused by us)
+    order_table = list(data[0x3B8:0x438])
+
+    magic = data[0x438:0x43C]
+    n_channels = _parse_magic(magic)
+    if n_channels == 0:
+        # Some very old MODs have only 15 samples and no magic. Detect 15-sample MOD.
+        # Header is 0x14 (title) + 15*30 (samples) = 0x14 + 0x1C2 = 0x1D6.
+        # Order table at 0x1D6, then 0x1D6+0x80 = 0x256, then patterns directly.
+        # We don't auto-detect that; require a magic.
+        sys.exit(f"error: unrecognised MOD magic {magic!r} at 0x438; "
+                 f"expected M.K., M!K!, FLT4, FLT8, xCHN or xxCH")
+
+    # Order list: only the first song_length entries are part of the song.
+    # Pattern count = 1 + max(order_table[0..127]) (scan all 128).
+    n_patterns = 1 + max(order_table)
+
+    pat_data_off = 0x43C
+    cell_size    = 4
+    pattern_size = MOD_PATTERN_ROWS * n_channels * cell_size
+
+    # Parse patterns
+    patterns = []   # patterns[pat_idx][channel][row] -> ModRow
+    for pi in range(n_patterns):
+        grid = [[ModRow() for _ in range(MOD_PATTERN_ROWS)] for _ in range(n_channels)]
+        base = pat_data_off + pi * pattern_size
+        if base + pattern_size > len(data):
+            vprint(f"  warning: pattern {pi} truncated; padding with empty rows")
+            patterns.append(grid)
+            continue
+        for r in range(MOD_PATTERN_ROWS):
+            row_off = base + r * n_channels * cell_size
+            for ch in range(n_channels):
+                cell_off = row_off + ch * cell_size
+                b0 = data[cell_off]
+                b1 = data[cell_off + 1]
+                b2 = data[cell_off + 2]
+                b3 = data[cell_off + 3]
+                period = ((b0 & 0x0F) << 8) | b1
+                inst   = (b0 & 0xF0) | ((b2 >> 4) & 0x0F)
+                effect = b2 & 0x0F
+                arg    = b3
+                # MT-style PT-strict cell rewrites (LoaderMOD.cpp:354-365):
+                # PT does not recall arg for portamento up/down (1xx, 2xx) or
+                # volume slide (Axx); the literal arg is read every tick. The
+                # vol-slide nibbles in 5xx/6xx likewise take literal args, with
+                # the recalled state living in the porta/vibrato side. So a
+                # zero-arg cell decays to a no-slide variant: 1/2/A drop to
+                # no-op, 5 collapses to bare tone-porta (3), 6 to bare vibrato
+                # (4). Without this, resolve_pt_recalls would back-fill these
+                # zero args from the cohort memory and produce a continuous
+                # slide where PT plays a single-row swell (canonical bug:
+                # GSLINGER ord 0x03 ch1 — `5 01` on r30/r38 with `5 00` on the
+                # rest, was fading 24→0 in 5 rows instead of stair-stepping
+                # 24→14 across 16 rows).
+                if arg == 0:
+                    if effect in (0x1, 0x2, 0xA):
+                        effect = 0x0
+                    elif effect == 0x5:
+                        effect = 0x3
+                    elif effect == 0x6:
+                        effect = 0x4
+                cell = grid[ch][r]
+                cell.period     = period
+                cell.inst       = inst
+                cell.effect     = effect
+                cell.effect_arg = arg
+        patterns.append(grid)
+
+    # Sample data follows pattern data
+    sample_off = pat_data_off + n_patterns * pattern_size
+    for s in samples:
+        if s.length == 0:
+            continue
+        n = min(s.length, max(0, len(data) - sample_off))
+        if n <= 0:
+            break
+        raw = data[sample_off:sample_off + n]
+        # PT samples are signed 8-bit; convert to unsigned by XOR 0x80.
+        s.sample_data = bytes((b ^ 0x80) for b in raw)
+        s.length      = len(s.sample_data)
+        if s.flags:
+            s.loop_begin = min(s.loop_begin, s.length)
+            s.loop_end   = min(s.loop_end,   s.length)
+        sample_off += n
+
+    return {
+        'title':      title,
+        'samples':    samples,
+        'order_list': order_table[:song_length],
+        'order_full': order_table,
+        'n_channels': n_channels,
+        'n_patterns': n_patterns,
+        'patterns':   patterns,
+        'magic':      magic,
+    }
+
+
+def _signed4(nibble: int) -> int:
+    """Convert a 4-bit unsigned nibble to signed -8..+7."""
+    return nibble - 16 if nibble >= 8 else nibble
+
+
+# ── Note encoding (period → Taud) ────────────────────────────────────────────
+
+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(0x20, min(0xFFFF, val))
+
+
+# ── PT effect → Taud effect ──────────────────────────────────────────────────
+
+def encode_effect(cmd: int, arg: int, ch: int = 0, row: int = 0) -> tuple:
+    """Return (taud_op, taud_arg16, vol_override, pan_override).
+
+    The caller is responsible for resolving PT zero-arg recalls before this
+    point — see resolve_pt_recalls(). cmd is the raw PT digit ($0..$F).
+    """
+    # $0 with arg 0 is a true no-op; $0 with arg != 0 is arpeggio.
+    if cmd == 0x0:
+        if arg == 0:
+            return (TOP_NONE, 0, None, None)
+        hi = (arg >> 4) & 0xF
+        lo = arg & 0xF
+        return (TOP_J, (J_SEMI_TABLE[hi] << 8) | J_SEMI_TABLE[lo], None, None)
+
+    # PT is Amiga-cycle-based by definition (the Taud Amiga-mode flag is set in
+    # the song table, see end of build_taud()).  E/F coarse pitch-slide arguments
+    # are therefore stored as raw PT period units; the engine consumes them
+    # directly in period space.  G (tone portamento) is treated as linear even
+    # in Amiga mode per the Taud spec, so its argument is still quantised to
+    # 4096-TET units.  Fine slides (E1x/E2x below) likewise remain linear.
+    if cmd == 0x1:
+        return (TOP_F, arg & 0xFFFF, None, None)
+
+    if cmd == 0x2:
+        return (TOP_E, arg & 0xFFFF, None, None)
+
+    if cmd == 0x3:
+        return (TOP_G, round(arg * 64 / 3) & 0xFFFF, None, None)
+
+    if cmd == 0x4:
+        hi = (arg >> 4) & 0xF
+        lo = arg & 0xF
+        return (TOP_H, ((hi * 0x11) << 8) | (lo * 0x11), None, None)
+
+    if cmd == 0x5:
+        # Tone porta + vol slide → Taud L verbatim. PT's 500 recall is already
+        # collapsed by resolve_pt_recalls; if the source had no prior 5xy the
+        # resolved arg is 0, which Taud's L $0000 then recalls from L's own
+        # private memory. Emitting a real L (rather than the previous
+        # G+vol-col split) preserves the slide on rows that also carry a
+        # vol-column SET (e.g., a Cxx fold) — see TAUD_NOTE_EFFECTS.md §L.
+        return (TOP_L, (arg & 0xFF) << 8, None, None)
+
+    if cmd == 0x6:
+        # Vibrato + vol slide → Taud K verbatim (same rationale as 0x5).
+        return (TOP_K, (arg & 0xFF) << 8, None, None)
+
+    if cmd == 0x7:
+        hi = (arg >> 4) & 0xF
+        lo = arg & 0xF
+        return (TOP_R, ((hi * 0x11) << 8) | (lo * 0x11), None, None)
+
+    if cmd == 0x8:
+        # PT 8xx is fine pan (or unused/sync in some trackers). Map to pan
+        # column 0.$yy where yy is the upper 6 bits of the 8-bit pan.
+        return (TOP_NONE, 0, None, (SEL_SET, (arg >> 2) & 0x3F))
+
+    if cmd == 0x9:
+        return (TOP_O, (arg & 0xFF) << 8, None, None)
+
+    if cmd == 0xA:
+        # Route Axy via Taud's effect-column D so it can coexist with a Cxx
+        # SET on the same row. (Vol-column slide selectors share the cell with
+        # the SET selector — when both Cxx and Axy land on a trigger row the
+        # vol-col slot can only encode one, and the slide gets dropped, losing
+        # 5 ticks of slide per row.) Resolution-time A00 is already collapsed
+        # to a concrete arg in resolve_pt_recalls; a remaining 0 means truly
+        # no-op (memory was empty), so emit nothing rather than D 00 (which
+        # would recall TSVM's D memory).
+        if arg == 0:
+            return (TOP_NONE, 0, None, None)
+        return (TOP_D, (arg & 0xFF) << 8, None, None)
+
+    if cmd == 0xB:
+        return (TOP_B, arg & 0xFF, None, None)
+
+    if cmd == 0xC:
+        # Caller folds Cxx into vol_set during parsing; this branch is a
+        # safety net in case a Cxx slips through.
+        return (TOP_NONE, 0, (SEL_SET, min(arg, 0x3F)), None)
+
+    if cmd == 0xD:
+        # PT pattern break is BCD on disk.
+        bcd_row = ((arg >> 4) & 0xF) * 10 + (arg & 0xF)
+        if bcd_row >= PATTERN_ROWS:
+            bcd_row = 0
+        return (TOP_C, bcd_row & 0xFF, None, None)
+
+    if cmd == 0xE:
+        sub = (arg >> 4) & 0xF
+        x   = arg & 0xF
+        if sub == 0x0:
+            # E0x = filter on/off (Amiga LED filter); no Taud equivalent.
+            return (TOP_NONE, 0, None, None)
+        if sub == 0x1:
+            # Fine pitch up — raw PT period units in Amiga mode (file is always Amiga).
+            return (TOP_F, 0xF000 | (x & 0xFFF), None, None)
+        if sub == 0x2:
+            # Fine pitch down — raw PT period units in Amiga mode.
+            return (TOP_E, 0xF000 | (x & 0xFFF), None, None)
+        if sub == 0x3:
+            return (TOP_S, 0x1000 | (x << 8), None, None)
+        if sub == 0x4:
+            return (TOP_S, 0x3000 | (x << 8), None, None)
+        if sub == 0x5:
+            return (TOP_S, 0x2000 | (x << 8), None, None)
+        if sub == 0x6:
+            return (TOP_S, 0xB000 | (x << 8), None, None)
+        if sub == 0x7:
+            return (TOP_S, 0x4000 | (x << 8), None, None)
+        if sub == 0x8:
+            # Coarse pan (4-bit). Map nibble 0..15 to pan 0..63 via × 4.2.
+            return (TOP_NONE, 0, None, (SEL_SET, round(x * 4.2)))
+        if sub == 0x9:
+            return (TOP_Q, (x & 0xF) << 8, None, None)
+        if sub == 0xA:
+            # Fine vol slide up.
+            return (TOP_NONE, 0, (SEL_FINE, (x & 0xF) | 0x20), None)
+        if sub == 0xB:
+            # Fine vol slide down.
+            return (TOP_NONE, 0, (SEL_FINE, x & 0xF), None)
+        if sub == 0xC:
+            return (TOP_S, 0xC000 | (x << 8), None, None)
+        if sub == 0xD:
+            return (TOP_S, 0xD000 | (x << 8), None, None)
+        if sub == 0xE:
+            return (TOP_S, 0xE000 | (x << 8), None, None)
+        if sub == 0xF:
+            funk_table = [0, 5, 6, 7, 8, 0xA, 0xB, 0xD, 0x10, 0x13, 0x16, 0x1A, 0x20, 0x2B, 0x40, 0x80]
+            return (TOP_S, 0xF000 | funk_table[x], None, None)
+        return (TOP_NONE, 0, None, None)
+
+    if cmd == 0xF:
+        if arg < 0x20:
+            if arg == 0:
+                return (TOP_NONE, 0, None, None)
+            return (TOP_A, (arg & 0xFF) << 8, None, None)
+        return (TOP_T, ((arg - 0x19) & 0xFF) << 8, None, None)
+
+    return (TOP_NONE, 0, None, None)
+
+
+def relocate_late_note_delays(patterns: list, order_list: list,
+                              n_channels: int, initial_speed: int) -> None:
+    """Move EDx-delayed notes to the next row when x ≥ tick speed.
+
+    PT triggers a Note Delay during the current row; if x reaches the tick
+    speed, the trigger never lands. When the next row in the same channel is
+    empty, relocate the note (with delay = x − speed) so it actually plays.
+    """
+    visited = set()
+    for order in order_list:
+        if order >= 0xFF:
+            break
+        if order >= len(patterns) or order in visited:
+            continue
+        visited.add(order)
+        grid = patterns[order]
+        speed = initial_speed
+        for r in range(MOD_PATTERN_ROWS):
+            for ch in range(min(n_channels, len(grid))):
+                row = grid[ch][r]
+                if row.effect == 0xF and 0 < row.effect_arg < 0x20:
+                    speed = row.effect_arg
+                    break
+            if r + 1 >= MOD_PATTERN_ROWS or speed <= 0:
+                continue
+            for ch in range(min(n_channels, len(grid))):
+                row = grid[ch][r]
+                if row.effect != 0xE or row.period == 0:
+                    continue
+                if ((row.effect_arg >> 4) & 0xF) != 0xD:
+                    continue
+                x = row.effect_arg & 0xF
+                if x < speed:
+                    continue
+                nxt = grid[ch][r + 1]
+                if (nxt.period or nxt.inst or nxt.effect or nxt.effect_arg
+                        or nxt.vol_set != -1):
+                    continue
+                new_delay = x - speed
+                nxt.period     = row.period
+                nxt.inst       = row.inst
+                nxt.vol_set    = row.vol_set
+                if new_delay > 0:
+                    nxt.effect     = 0xE
+                    nxt.effect_arg = 0xD0 | (new_delay & 0xF)
+                row.period     = 0
+                row.inst       = 0
+                row.effect     = 0
+                row.effect_arg = 0
+                row.vol_set    = -1
+                vprint(f"  fix: pat{order} ch{ch} row{r}: ED{x:X} ≥ speed{speed}, "
+                       f"moved note to row{r+1}"
+                       + (f" with ED{new_delay:X}" if new_delay > 0 else ""))
+
+
+def resolve_pt_recalls(patterns: list, order_list: list, n_channels: int) -> None:
+    """In-place: replace PT zero-arg recalls with each effect's last non-zero arg.
+
+    PT memory is per-effect-private. Walking patterns in order-list order,
+    we track each channel's last non-zero arg per memorising effect and
+    rewrite recall args to make them explicit.
+    """
+    # mem[ch][key] = last_non_zero_arg
+    # key is either an int (top-level 0..F) or a tuple ('E', sub) for E-subs.
+    mem = [dict() for _ in range(n_channels)]
+    for order in order_list:
+        if order >= 0xFF:
+            break
+        if order >= len(patterns):
+            continue
+        grid = patterns[order]
+        for r in range(MOD_PATTERN_ROWS):
+            for ch in range(n_channels):
+                if ch >= len(grid):
+                    continue
+                row = grid[ch][r]
+                cmd = row.effect
+                arg = row.effect_arg
+                if cmd in PT_MEM_TOP:
+                    if arg == 0:
+                        row.effect_arg = mem[ch].get(cmd, 0)
+                    else:
+                        mem[ch][cmd] = arg
+                elif cmd == 0xE:
+                    sub = (arg >> 4) & 0xF
+                    x   = arg & 0xF
+                    if sub in PT_MEM_E_SUB:
+                        key = ('E', sub)
+                        if x == 0:
+                            recalled = mem[ch].get(key, 0)
+                            row.effect_arg = (sub << 4) | (recalled & 0xF)
+                        else:
+                            mem[ch][key] = x
+
+
+# ── Sample resampling and Taud sample/instrument bin (port of s3m2taud) ──────
+
+def build_sample_inst_bin(samples: list) -> tuple:
+    """Returns (bin_bytes[786432], offsets_dict). 1-based indexing."""
+    pcm = [(i, s) for i, s in enumerate(samples) if s.sample_data]
+
+    total = sum(len(s.sample_data) for _, s in pcm)
+    ratio = 1.0
+    if total > SAMPLEBIN_SIZE:
+        ratio = SAMPLEBIN_SIZE / total
+        vprint(f"  info: sample bin overflow ({total} bytes); resampling all by {ratio:.4f}")
+        for _, s in pcm:
+            new_data    = resample_linear(s.sample_data, ratio)
+            s.sample_data = new_data
+            s.length      = len(new_data)
+            s.loop_begin  = max(0, int(s.loop_begin * ratio))
+            s.loop_end    = max(0, min(int(s.loop_end * ratio), s.length))
+            s.c2spd       = max(1, int(s.c2spd * ratio))
+
+    sample_bin = bytearray(SAMPLEBIN_SIZE)
+    offsets    = {}
+    pos        = 0
+    for idx, s in pcm:
+        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
+        if n < len(s.sample_data):
+            vprint(f"  warning: '{s.name}' truncated from {len(s.sample_data)} to {n}")
+            s.length   = n
+            s.loop_end = min(s.loop_end, n)
+        pos += n
+
+    # New 256-byte instrument layout (terranmon.txt:2001+).
+    INST_STRIDE = 256
+    inst_bin = bytearray(INSTBIN_SIZE)
+    for i, s in enumerate(samples):
+        taud_idx = i + 1     # 1-based instrument number
+        if i >= 256:
+            break
+        if not s.sample_data:
+            continue
+        ptr      = offsets.get(i, 0) & 0xFFFFFFFF
+        s_len    = min(s.length, 65535)
+        c2spd    = min(s.c2spd, 65535)
+        ps       = 0
+        ls       = min(s.loop_begin, 65535)
+        le       = min(s.loop_end,   65535)
+        loop_mode = 1 if (s.flags & 1) else 0
+        flags_byte = loop_mode & 0x3
+        # Envelope first point is full-scale; per-trigger initial level is
+        # carried by Default Note Volume (byte 196) so the envelope must
+        # contribute a unit multiplier.
+        env_vol   = 63
+        # MOD has no envelopes; vol LOOP word b=1 just so the engine evaluates
+        # the unit envelope, plus P=1 (envelope present) for consistency with
+        # the new gate spec (terranmon.txt byte 16/18/20 bit 5). Pan/PF stay
+        # fully zero — the engine sees P=0 there and skips them.
+        vol_env_loop = 0x2020   # P (bit 13) | b (bit 5)
+
+        base = taud_idx * INST_STRIDE
+        struct.pack_into('<I', inst_bin, base + 0,  ptr)
+        struct.pack_into('<H', inst_bin, base + 4,  s_len)
+        struct.pack_into('<H', inst_bin, base + 6,  c2spd)
+        struct.pack_into('<H', inst_bin, base + 8,  ps)
+        struct.pack_into('<H', inst_bin, base + 10, ls)
+        struct.pack_into('<H', inst_bin, base + 12, le)
+        inst_bin[base + 14] = flags_byte
+        # LOOP words at 15/17/19; SUSTAIN words at 189/191/193 (left zero).
+        struct.pack_into('<H', inst_bin, base + 15, vol_env_loop)
+        struct.pack_into('<H', inst_bin, base + 17, 0)
+        struct.pack_into('<H', inst_bin, base + 19, 0)
+        inst_bin[base + 21] = env_vol
+        inst_bin[base + 22] = 0
+        # MOD has no continuous instrumentwise volume scaler — its `s.volume`
+        # (0..64) is purely the per-trigger initial value. Byte 171 (IGV)
+        # stays at full and byte 196 (DNV) carries the per-instrument default.
+        # Pre-2026-05-09 layout folded s.volume into IGV — see terranmon §2350.
+        inst_bin[base + 171] = 0xFF                                                 # IGV: continuous unity
+        inst_bin[base + 177] = 0x80 # default pan = centre (unused; pan env "p" flag not set)
+        inst_bin[base + 182] = 0xFF # filter cutoff = off
+        inst_bin[base + 183] = 0xFF # filter resonance = off
+        inst_bin[base + 186] = 1 # NNA: note cut
+        inst_bin[base + 196] = min(0xFF, round(min(s.volume, 64) * 255 / 64))       # DNV
+
+        vprint(f"  instrument[{taud_idx}] '{s.name}' ptr={ptr} c2spd={s.c2spd} "
+               f"vol={s.volume} loop=({ls},{le},{'on' if loop_mode else 'off'})")
+
+    return bytes(sample_bin) + bytes(inst_bin), offsets, ratio
+
+
+# ── Pattern build ────────────────────────────────────────────────────────────
+
+# 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 8 if side in (0, 3) else 55
+
+
+def build_pattern(grid: list, ch_idx: int, default_pan: int,
+                  inst_vols: dict) -> bytes:
+    """Build a 512-byte Taud pattern for one MOD channel.
+
+    Volume column: explicit Cxx → SEL_SET; effect-folded vol slide → vol_override;
+    otherwise SEL_FINE/0 (no-op). Per-instrument default volume lives in DNV
+    (byte 196) and is consulted by the engine when the trigger row has no V
+    column — the converter doesn't need to emit SEL_SET=Sv on plain triggers.
+    """
+    out = bytearray(PATTERN_BYTES)
+    rows = grid[ch_idx] if ch_idx < len(grid) else [ModRow()] * MOD_PATTERN_ROWS
+    last_inst = 0
+    last_period = 0
+    for r, row in enumerate(rows[:MOD_PATTERN_ROWS]):
+        note_taud = period_to_taud_note(row.period)
+        note_triggers = (row.period > 0)
+
+        if row.inst > 0:
+            last_inst = row.inst
+
+        op, arg, vol_override, pan_override = encode_effect(
+            row.effect, row.effect_arg, ch_idx, r)
+
+        # ── Volume column ──
+        if row.vol_set >= 0:
+            vol_sel, vol_value = SEL_SET, min(row.vol_set, 0x3F)
+            if vol_override is not None and vol_override[0] != SEL_SET:
+                vprint(f"    ch{ch_idx} row{r}: dropped vol slide "
+                       f"(cell already carries explicit Cxx volume)")
+        elif vol_override is not None:
+            vol_sel, vol_value = vol_override
+        else:
+            vol_sel, vol_value = SEL_FINE, 0
+
+        if note_triggers:
+            last_period = row.period
+
+        # ── Pan column ──
+        if pan_override is not None:
+            pan_sel, pan_value = pan_override
+        elif r == 0:
+            pan_sel, pan_value = SEL_SET, default_pan & 0x3F
+        else:
+            pan_sel, pan_value = SEL_FINE, 0
+
+        vol_byte = (vol_value & 0x3F) | ((vol_sel & 0x3) << 6)
+        pan_byte = (pan_value & 0x3F) | ((pan_sel & 0x3) << 6)
+
+        base = r * 8
+        struct.pack_into('<H', out, base + 0, note_taud)
+        out[base + 2] = row.inst & 0xFF
+        out[base + 3] = vol_byte
+        out[base + 4] = pan_byte
+        out[base + 5] = op & 0xFF
+        struct.pack_into('<H', out, base + 6, arg & 0xFFFF)
+    return bytes(out)
+
+
+def build_cue_sheet(order_list: list, n_pats_mod: int, n_channels: int,
+                    pat_remap: dict = None) -> bytes:
+    sheet = bytearray(NUM_CUES * CUE_SIZE)
+    for c in range(NUM_CUES):
+        sheet[c*CUE_SIZE : c*CUE_SIZE+CUE_SIZE] = encode_cue([], 0)
+
+    cue_idx = 0
+    last_active = -1
+    for order in order_list:
+        if order == 0xFF or cue_idx >= NUM_CUES:
+            break
+        if order == 0xFE:
+            continue
+        if order >= n_pats_mod:
+            continue
+        orig = [order * n_channels + v for v in range(n_channels)]
+        pats = [pat_remap[p] if pat_remap else p for p in orig]
+        sheet[cue_idx*CUE_SIZE : cue_idx*CUE_SIZE+CUE_SIZE] = encode_cue(pats, 0)
+        last_active = cue_idx
+        cue_idx += 1
+
+    if last_active >= 0:
+        sheet[last_active * CUE_SIZE + 30] = 0x01
+    elif cue_idx < NUM_CUES:
+        sheet[30] = 0x01
+
+    return bytes(sheet)
+
+
+def find_initial_bpm_speed(patterns: list, order_list: list) -> tuple:
+    """Scan first pattern in order for Fxx in row 0 of any channel."""
+    speed = 6
+    tempo = 125
+    for order in order_list:
+        if order >= 0xFF:
+            break
+        if order >= len(patterns):
+            continue
+        grid = patterns[order]
+        for ch_rows in grid:
+            row = ch_rows[0]
+            if row.effect == 0xF and row.effect_arg > 0:
+                if row.effect_arg < 0x20:
+                    speed = row.effect_arg
+                else:
+                    tempo = row.effect_arg
+        break
+    return speed, tempo
+
+
+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))):
+            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
+
+
+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.
+
+    `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]
+
+    vprint(f"  [{song_label}] resolving PT per-effect recalls…")
+    resolve_pt_recalls(patterns, virtual_orders, n_channels)
+
+    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"  [{song_label}] initial speed={speed}, tempo(BPM)={tempo}")
+
+    n_patterns = mod['n_patterns']
+
+    # 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")
+
+    pat_bin = bytearray()
+    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)
+    pat_bin = rescale_offset_effects(bytes(pat_bin), sample_ratio)
+
+    orig_count = P_used * n_channels
+    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
+    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")
+
+    flags_byte = GLOBAL_FLAGS_AMIGA_FREQ | GLOBAL_FLAGS_A500_INTP
+    entry_kwargs = dict(
+        num_voices=n_channels,
+        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=180,
+    )
+    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).
+    proj_data = b''
+    proj_off  = 0
+    if with_project_data:
+        names = [''] + [s.name for s in samples[:255]]
+        proj_data = build_project_data(
+            project_name=mod['title'],
+            instrument_names=names,
+            sample_names=names,
+        )
+        if proj_data:
+            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, n_songs & 0xFF]) +
+        struct.pack('<I', comp_size) +
+        struct.pack('<I', proj_off) +
+        sig
+    )
+    assert len(header) == TAUD_HEADER_SIZE
+
+    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 ─────────────────────────────────────────────────────────────────────
+
+def main():
+    ap = argparse.ArgumentParser(description=__doc__,
+                                 formatter_class=argparse.RawDescriptionHelpFormatter)
+    ap.add_argument('input',  help='Input .mod file')
+    ap.add_argument('output', help='Output .taud file')
+    ap.add_argument('-v', '--verbose', action='store_true',
+                    help='Print conversion details to stderr')
+    ap.add_argument('--no-project-data', action='store_true',
+                    help='Omit the optional Project Data section '
+                         '(song / instrument / sample names)')
+    args = ap.parse_args()
+
+    set_verbose(args.verbose)
+
+    with open(args.input, 'rb') as f:
+        data = f.read()
+
+    vprint(f"parsing '{args.input}' ({len(data)} bytes)…")
+    mod = parse_mod(data)
+    vprint(f"  title: '{mod['title']}'")
+    vprint(f"  magic: {mod['magic']!r} ({mod['n_channels']} channels)")
+    vprint(f"  orders={len(mod['order_list'])}, patterns={mod['n_patterns']}, "
+           f"samples={sum(1 for s in mod['samples'] if s.sample_data)}")
+
+    taud = assemble_taud(mod, with_project_data=not args.no_project_data)
+
+    with open(args.output, 'wb') as f:
+        f.write(taud)
+
+    print(f"wrote {len(taud)} bytes to '{args.output}'")
+    if args.verbose:
+        print(f"  magic ok: {taud[:8].hex()}", file=sys.stderr)
+
+
+if __name__ == '__main__':
+    main()

mon2taud.py

@@ -0,0 +1,558 @@
+#!/usr/bin/env python3
+"""mon2taud.py — Convert Monotone (.MON) tracker modules to TSVM Taud (.taud)
+
+Usage:
+    python3 mon2taud.py input.MON output.taud [-v]
+
+Monotone is Calvin "Trixter" French's tracker for the PC speaker / Tandy /
+TI-99 SN76489. It has no user-defined instruments (the only instrument is
+the beeper), 1..12 voices, 64 rows per pattern, ProTracker-flavoured 2-byte
+cells and a reduced 8-effect set: 0,1,2,3,4,B,D,F.
+
+This converter:
+    - synthesises a single 32-byte squarewave instrument (instrument #1)
+    - splits each Monotone pattern (64 × N voices) into N Taud patterns
+    - converts notes (A0=27.5 Hz chromatic) to Taud 4096-TET centred on C4
+    - maps the 8 Monotone effects to their closest Taud equivalents
+    - emits Hz/tick slides (1xx/2xx/3xx) verbatim and turns on Taud's
+      linear-frequency tone mode (Effect 1 ff=2) so the engine interprets
+      E/F/G arguments as Hz at A4=440 Hz reference — no scaling drift
+
+Limits: numVoices ≤ 20, numPatterns × numVoices ≤ 4095.
+"""
+
+import argparse
+import copy
+import struct
+import sys
+
+from taud_common import (
+    set_verbose, vprint,
+    TAUD_MAGIC, TAUD_VERSION, TAUD_HEADER_SIZE, TAUD_SONG_ENTRY,
+    SAMPLEBIN_SIZE, INSTBIN_SIZE, SAMPLEINST_SIZE,
+    PATTERN_ROWS, PATTERN_BYTES, NUM_PATTERNS_MAX, NUM_CUES, CUE_SIZE, NUM_VOICES,
+    NOTE_NOP, NOTE_KEYOFF, NOTE_CUT, TAUD_C4,
+    TOP_NONE, TOP_A, TOP_B, TOP_C, TOP_E, TOP_F, TOP_G, TOP_H, TOP_J,
+    SEL_SET, SEL_FINE,
+    J_SEMI_TABLE,
+    encode_cue, deduplicate_patterns, encode_song_entry, compress_blob,
+    build_project_data, detect_subsongs,
+)
+
+
+# ── Monotone constants ───────────────────────────────────────────────────────
+
+MON_MAGIC_PREFIX  = b'\x08MONOTONE'        # only the first 9 bytes are stable
+MON_HEADER_SIZE   = 0x15F                  # 92 magic + 3 meta + 256 order list
+MON_PATTERN_ROWS  = 64
+MON_CELL_BYTES    = 2
+
+# Effect-code (3-bit) → ProTracker-style letter, following the format-doc table.
+MON_EFFECT_LETTERS = ['0', '1', '2', '3', '4', 'B', 'D', 'F']
+
+# Note value 1 = A0; C4 sits at value 40 (A0 + 39 semitones).
+MON_NOTE_C4 = 40
+
+# Global behaviour flags byte (Taud Effect 1 / song-table byte 15):
+#   bits 0-1 (ff): tone mode — 2 = linear-frequency (Hz/tick)
+# Selecting ff=2 makes the engine interpret 1xx/2xx/3xx slide arguments in
+# audible Hz at the A4=440 Hz reference, matching Monotone's MT_PLAY.PAS
+# `Frequency:=Frequency±parm1` arithmetic (see MTSRC/MT_PLAY.PAS:606-630).
+# Panning law is fixed to the equal-energy — there is no `p` bit any more.
+GLOBAL_FLAGS_LINEAR_FREQ = 0b10
+GLOBAL_FLAGS_NO_INTERPOLATION = 0b0100
+
+
+# ── Taud container ───────────────────────────────────────────────────────────
+
+SIGNATURE = b"mon2taud/TSVM "    # 14 bytes
+
+
+# ── Monotone parser ──────────────────────────────────────────────────────────
+
+class MonRow:
+    __slots__ = ('note', 'effect', 'effect_arg')
+    def __init__(self):
+        self.note       = 0      # 0 = empty, 0x7F = note off, else 1..126
+        self.effect     = 0      # 0..7 (raw 3-bit code)
+        self.effect_arg = 0      # 0..63 (6-bit data)
+
+
+def parse_mon(data: bytes):
+    if len(data) < MON_HEADER_SIZE:
+        sys.exit(f"error: file too short ({len(data)} bytes); "
+                 f"need at least {MON_HEADER_SIZE} for the header")
+
+    if data[:9] != MON_MAGIC_PREFIX:
+        sys.exit(f"error: bad magic; expected '\\x08MONOTONE', got {data[:9]!r}")
+
+    song_len   = data[0x5C]
+    num_voices = data[0x5D]
+    if num_voices < 1 or num_voices > 12:
+        sys.exit(f"error: invalid voice count {num_voices} (expected 1..12)")
+
+    order_raw = data[0x5F:0x15F]
+    # Effective order list: take first song_len entries and drop 0xFF skip-slots
+    # (matches mtreader.lua and MT_PLAY.PAS' "ignore 0xFF" semantics).
+    order_list = [b for b in order_raw[:song_len] if b != 0xFF]
+    if not order_list:
+        sys.exit("error: order list is empty after filtering 0xFF skip slots")
+
+    n_patterns = max(order_list) + 1
+    pattern_size = MON_PATTERN_ROWS * num_voices * MON_CELL_BYTES
+    expected = MON_HEADER_SIZE + n_patterns * pattern_size
+    if len(data) < expected:
+        sys.exit(f"error: file truncated; expected {expected} bytes for "
+                 f"{n_patterns} patterns × {num_voices} voices, got {len(data)}")
+
+    # patterns[pi][voice][row] -> MonRow
+    patterns = []
+    for pi in range(n_patterns):
+        base = MON_HEADER_SIZE + pi * pattern_size
+        grid = [[MonRow() for _ in range(MON_PATTERN_ROWS)] for _ in range(num_voices)]
+        for r in range(MON_PATTERN_ROWS):
+            row_off = base + r * num_voices * MON_CELL_BYTES
+            for v in range(num_voices):
+                cell_off = row_off + v * MON_CELL_BYTES
+                # Little-endian 16-bit cell.
+                word = data[cell_off] | (data[cell_off + 1] << 8)
+                cell = grid[v][r]
+                cell.note       = (word >> 9) & 0x7F
+                cell.effect     = (word >> 6) & 0x07
+                cell.effect_arg = word & 0x3F
+        patterns.append(grid)
+
+    return {
+        'song_len':   song_len,
+        'num_voices': num_voices,
+        'order_list': order_list,
+        'n_patterns': n_patterns,
+        'patterns':   patterns,
+    }
+
+
+# ── Note conversion (Monotone → Taud 4096-TET) ───────────────────────────────
+
+def mon_note_to_taud(mon_note: int) -> int:
+    if mon_note == 0:
+        return NOTE_NOP
+    if mon_note == 0x7F:
+        return NOTE_CUT
+    val = TAUD_C4 + round((mon_note - MON_NOTE_C4) * 4096.0 / 12.0)
+    return max(0x20, min(0xFFFF, val))
+
+
+# ── Effect mapping (Monotone 3-bit code + 6-bit data → Taud) ─────────────────
+
+def encode_effect(eff_code: int, data: int) -> tuple:
+    """Return (taud_op, taud_arg16)."""
+    letter = MON_EFFECT_LETTERS[eff_code & 7]
+
+    if letter == '0':
+        if data == 0:
+            return (TOP_NONE, 0)
+        x = (data >> 3) & 0x7
+        y = data & 0x7
+        return (TOP_J, (J_SEMI_TABLE[x] << 8) | J_SEMI_TABLE[y])
+
+    if letter == '1':                                # slide up Hz/tick → Taud F (Hz/tick under ff=2)
+        return (TOP_F, data & 0xFFFF)
+
+    if letter == '2':                                # slide down Hz/tick → Taud E (Hz/tick under ff=2)
+        return (TOP_E, data & 0xFFFF)
+
+    if letter == '3':                                # tone porta Hz/tick → Taud G (Hz/tick under ff=2)
+        return (TOP_G, data & 0xFFFF)
+
+    if letter == '4':                                # vibrato xy → Taud H
+        x = (data >> 3) & 0x7        # speed (3 bits)
+        y = data & 0x7               # depth (3 bits)
+        # Scale 3-bit nibble (0..7) to 8-bit byte (0..252) via × 0x24 (= 36).
+        return (TOP_H, ((x * 0x24) << 8) | (y * 0x24))
+
+    if letter == 'B':                                # position jump → Taud B
+        return (TOP_B, data & 0xFF)
+
+    if letter == 'D':                                # pattern break → Taud C
+        return (TOP_C, data & 0xFF)
+
+    if letter == 'F':                                # set speed → Taud A
+        if data == 0:                                # invalid in Monotone
+            return (TOP_NONE, 0)
+        return (TOP_A, (data & 0xFF) << 8)
+
+    return (TOP_NONE, 0)
+
+
+# ── Squarewave instrument synthesis ──────────────────────────────────────────
+
+# 32-byte single-cycle 50%-duty square; played at 8372 Hz at C4 → 261.6 Hz tone.
+SQUARE_SAMPLE = bytes([0xFF] * 16 + [0x00] * 16)
+SQUARE_C2SPD  = 8372
+
+def build_sample_inst_bin() -> bytes:
+    """Emit the full 786432-byte sample+instrument bin.
+
+    Instrument 1 carries the synthesised square wave; all other slots stay
+    zero. Sample bin starts with the 32-byte square at offset 0; rest is
+    silence padding.
+    """
+    sample_bin = bytearray(SAMPLEBIN_SIZE)
+    sample_bin[0:len(SQUARE_SAMPLE)] = SQUARE_SAMPLE
+
+    inst_bin = bytearray(INSTBIN_SIZE)
+    base = 1 * 256       # instrument #1 (slot 0 always blank)
+    struct.pack_into('<I', inst_bin, base + 0,  0)                       # sample ptr
+    struct.pack_into('<H', inst_bin, base + 4,  len(SQUARE_SAMPLE))      # length
+    struct.pack_into('<H', inst_bin, base + 6,  SQUARE_C2SPD)            # rate at C4
+    struct.pack_into('<H', inst_bin, base + 8,  0)                       # play start
+    struct.pack_into('<H', inst_bin, base + 10, 0)                       # loop start
+    struct.pack_into('<H', inst_bin, base + 12, len(SQUARE_SAMPLE))      # loop end
+    inst_bin[base + 14] = 0x01                                           # forward loop
+    struct.pack_into('<H', inst_bin, base + 15, 0x2020)                  # vol-env: P (bit 13) | b (bit 5)
+    struct.pack_into('<H', inst_bin, base + 17, 0)                       # pan-env flags (P=0 → mixer skips)
+    struct.pack_into('<H', inst_bin, base + 19, 0)                       # pitch-env flags (P=0 → mixer skips)
+    inst_bin[base + 21] = 63                                             # vol env pt 0 = full
+    inst_bin[base + 22] = 0
+    inst_bin[base + 171] = 0xA0                                          # IGV (square-wave headroom)
+    inst_bin[base + 177] = 0x80                                          # default pan = centre
+    inst_bin[base + 182] = 0xFF                                          # filter cutoff off
+    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 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)
+
+
+# ── Pattern build ────────────────────────────────────────────────────────────
+
+def build_taud_pattern(grid: list, voice: int) -> bytes:
+    """Build one 512-byte Taud pattern from one Monotone voice's 64 rows."""
+    out = bytearray(PATTERN_BYTES)
+    rows = grid[voice]
+    for r, row in enumerate(rows):
+        note_taud = mon_note_to_taud(row.note)
+        # Trigger instrument #1 only when an actual note (1..0x7E) starts.
+        triggers = (1 <= row.note <= 0x7E)
+
+        op, arg = encode_effect(row.effect, row.effect_arg)
+
+        # Volume column: Monotone has none → permanent no-op (FINE 0).
+        vol_byte = (SEL_FINE << 6) | 0
+        # Pan column: SET centre on row 0, no-op afterwards.
+        if r == 0:
+            pan_byte = (SEL_SET << 6) | 32
+        else:
+            pan_byte = (SEL_FINE << 6) | 0
+
+        base = r * 8
+        struct.pack_into('<H', out, base + 0, note_taud)
+        out[base + 2] = 1 if triggers else 0
+        out[base + 3] = vol_byte
+        out[base + 4] = pan_byte
+        out[base + 5] = op & 0xFF
+        struct.pack_into('<H', out, base + 6, arg & 0xFFFF)
+
+    return bytes(out)
+
+
+def build_cue_sheet(order_list: list, num_voices: int, pat_remap: dict) -> bytes:
+    """One cue per order-list entry; last cue carries the halt instruction."""
+    sheet = bytearray(NUM_CUES * CUE_SIZE)
+    for c in range(NUM_CUES):
+        sheet[c*CUE_SIZE : (c+1)*CUE_SIZE] = encode_cue([], 0)
+
+    cue_idx = 0
+    last_active = -1
+    for order in order_list:
+        if cue_idx >= NUM_CUES:
+            break
+        orig_pats = [order * num_voices + v for v in range(num_voices)]
+        mapped    = [pat_remap[p] for p in orig_pats]
+        sheet[cue_idx*CUE_SIZE : (cue_idx+1)*CUE_SIZE] = encode_cue(mapped, 0)
+        last_active = cue_idx
+        cue_idx += 1
+
+    if last_active >= 0:
+        sheet[last_active * CUE_SIZE + 30] = 0x01
+
+    return bytes(sheet)
+
+
+# ── Initial speed scan ───────────────────────────────────────────────────────
+
+def find_initial_speed(patterns: list, order_list: list, num_voices: int) -> int:
+    """Pick up an Fxx in the first ordered pattern's row 0 if present.
+
+    Default tempo per MT_PLAY.PAS:238-239 is `max(numTracks, 4)`.
+    """
+    default_speed = max(num_voices, 4)
+    if not order_list:
+        return default_speed
+    first = order_list[0]
+    if first >= len(patterns):
+        return default_speed
+    grid = patterns[first]
+    for v in range(num_voices):
+        row = grid[v][0]
+        if row.effect == 7 and 0 < row.effect_arg < 0x40:    # Fxx (idx 7)
+            return row.effect_arg
+    return default_speed
+
+
+# ── 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']
+    order_list = mon['order_list']
+    n_patterns = mon['n_patterns']
+
+    if num_voices > NUM_VOICES:
+        vprint(f"  warning: {num_voices} voices > {NUM_VOICES}; truncating")
+        num_voices = NUM_VOICES
+    vprint(f"  voices: {num_voices}, mon patterns: {n_patterns}")
+
+    vprint("  building sample/instrument bin…")
+    sampleinst_raw = build_sample_inst_bin()
+    assert len(sampleinst_raw) == SAMPLEINST_SIZE
+    compressed = compress_blob(sampleinst_raw, "sample+inst bin")
+    comp_size  = len(compressed)
+
+    # ── 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")
+
+    # ── 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))
+
+    # ── 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). Monotone has no title, no user instruments and
+    # no per-sample names, but we still emit one identifying entry so the
+    # synthesised square slot is documented.
+    proj_data = b''
+    proj_off  = 0
+    if with_project_data:
+        proj_data = build_project_data(
+            instrument_names=['', 'PC speaker square'],
+            sample_names=['', 'PC speaker square'],
+        )
+        if proj_data:
+            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, n_songs & 0xFF])
+        + struct.pack('<I', comp_size)
+        + struct.pack('<I', proj_off)
+        + sig
+    )
+    assert len(header) == TAUD_HEADER_SIZE
+
+    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 ─────────────────────────────────────────────────────────────────────
+
+def main():
+    ap = argparse.ArgumentParser(description=__doc__,
+                                 formatter_class=argparse.RawDescriptionHelpFormatter)
+    ap.add_argument('input',  help='Input .MON file')
+    ap.add_argument('output', help='Output .taud file')
+    ap.add_argument('-v', '--verbose', action='store_true',
+                    help='Print conversion details to stderr')
+    ap.add_argument('--no-project-data', action='store_true',
+                    help='Omit the optional Project Data section '
+                         '(song / instrument / sample names)')
+    args = ap.parse_args()
+
+    set_verbose(args.verbose)
+
+    with open(args.input, 'rb') as f:
+        data = f.read()
+
+    vprint(f"parsing '{args.input}' ({len(data)} bytes)…")
+    mon = parse_mon(data)
+    vprint(f"  songLen={mon['song_len']}, voices={mon['num_voices']}, "
+           f"patterns={mon['n_patterns']}, orders={len(mon['order_list'])}")
+
+    taud = assemble_taud(mon, with_project_data=not args.no_project_data)
+
+    with open(args.output, 'wb') as f:
+        f.write(taud)
+
+    print(f"wrote {len(taud)} bytes to '{args.output}'")
+    if args.verbose:
+        print(f"  magic ok: {taud[:8].hex()}", file=sys.stderr)
+
+
+if __name__ == '__main__':
+    main()

taud_common.py

@@ -0,0 +1,740 @@
+"""taud_common.py — Shared constants and helpers for *2taud converters.
+
+Imported by s3m2taud.py, it2taud.py, and mod2taud.py. Holds the Taud
+container constants, the effect-letter index table, and the small set
+of helpers (sample resampler, vol/pan column packer, cue encoder,
+pattern deduper, sample normaliser) that all three converters used to
+duplicate verbatim.
+"""
+
+import gzip as _gzip
+import struct
+import sys
+
+try:
+    import zstandard as _zstd
+    _ZSTD_CCTX = _zstd.ZstdCompressor(level=22)
+except ImportError:
+    _ZSTD_CCTX = None
+
+
+# ── Verbose logging (shared across converters via set_verbose) ───────────────
+
+VERBOSE = False
+
+def set_verbose(b: bool) -> None:
+    global VERBOSE
+    VERBOSE = bool(b)
+
+def vprint(*a, **kw) -> None:
+    if VERBOSE:
+        print(*a, **kw, file=sys.stderr)
+
+
+# ── Compression (gzip vs zstd; whichever is smaller) ─────────────────────────
+#
+# The Taud loader sniffs the 4-byte magic of every compressed slot and routes
+# to GZIPInputStream or ZstdInputStream accordingly (CompressorDelegate.kt:148-149),
+# so each blob can independently pick whichever codec compresses it smaller.
+
+def best_compress(payload: bytes) -> tuple:
+    """Return (compressed_bytes, method) for the smaller of gzip/zstd output.
+
+    Method is "gzip" or "zstd". Falls back to gzip when the `zstandard`
+    package is not installed.
+    """
+    gz = _gzip.compress(payload, compresslevel=9, mtime=0)
+    if _ZSTD_CCTX is None:
+        return gz, "gzip"
+    zs = _ZSTD_CCTX.compress(payload)
+    if len(zs) < len(gz):
+        return zs, "zstd"
+    return gz, "gzip"
+
+
+def compress_blob(payload: bytes, label: str) -> bytes:
+    """Compress `payload` with whichever of gzip/zstd is smaller; vprint stats; return bytes.
+
+    `label` is the human-readable name in the verbose log line, e.g. "sample+inst bin".
+    """
+    out, method = best_compress(payload)
+    vprint(f"  {label}: {len(payload)} → {len(out)} bytes ({method})")
+    return out
+
+
+# ── Taud container constants ─────────────────────────────────────────────────
+
+TAUD_MAGIC       = bytes([0x1F,0x54,0x53,0x56,0x4D,0x61,0x75,0x64])
+# Bumped 2026-05-07: envelope offset minifloat rebiased (smallest step 1/256 s,
+# max 15.75 s; previously 1/32 s, max 126 s). v1 .taud envelopes will play with
+# the wrong tempo on a v2 engine — re-convert from source.
+TAUD_VERSION     = 1
+TAUD_HEADER_SIZE = 32       # magic(8)+ver(1)+numSongs(1)+compSize(4)+projOff(4)+sig(14)
+TAUD_SONG_ENTRY  = 32       # full spec entry (see encode_song_entry)
+INST_RECORD_SIZE = 256      # widened 2026-05-06 (was 192). 256 inst × 256 = 64K.
+# Sample+instrument image (terranmon.txt:1985-1997, 2533-2564 — updated 2026-05-08).
+# Sample pool is now 8 MB, banked through MMIO 46 in 16 × 512 K windows.
+# Converters write the pool bank-major (bank 0's 512 K first, then bank 1's, ...);
+# the runtime decompresses the whole blob straight into native peripheral storage,
+# so converters just lay out an 8 MB linear array as if banking didn't exist.
+SAMPLE_BANK_SIZE = 524288               # 512 K per bank
+SAMPLE_BANK_COUNT = 16                  # 16 banks × 512 K = 8 MB
+SAMPLEBIN_SIZE   = SAMPLE_BANK_SIZE * SAMPLE_BANK_COUNT   # 8 MB
+INSTBIN_SIZE     = INST_RECORD_SIZE * 256   # 65536 = 64K
+SAMPLEINST_SIZE  = SAMPLEBIN_SIZE + INSTBIN_SIZE          # 8454144 = 8256 kB
+PATTERN_ROWS     = 64
+PATTERN_BYTES    = PATTERN_ROWS * 8     # 512
+NUM_PATTERNS_MAX = 4095
+NUM_CUES         = 1024
+CUE_SIZE         = 32
+NUM_VOICES       = 20
+
+# Per-sample length cap. Taud instrument records carry the sample length as
+# a u16 (terranmon.txt:2001+ — bytes 4..5), so any single sample must fit in
+# 65535 bytes. Converters resample over-long samples individually after the
+# global pool-overflow pass and rescale the affected channel's TOP_O args.
+SAMPLE_LEN_LIMIT = 65535
+
+# Note word sentinels
+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).
+# Per terranmon.txt §"Cue Sheet":
+#   00000010 00xxxxxx (LEN)  pattern length: rows = (xxxxxx) + 1, range 1..64
+#   00000001          (HALT) end of song
+#   00000000          (NOP)  default 64-row cue
+#   1000xxxx yyyyyyyy (BAK)  go back 12-bit arg
+#   1001xxxx yyyyyyyy (FWD)  skip forward 12-bit arg
+#   1111xxxx yyyyyyyy (JMP)  go to absolute pattern
+CUE_INST_NOP  = 0x00
+CUE_INST_HALT = 0x01
+CUE_INST_LEN  = 0x02
+
+# Taud effect opcodes (base-36: 0..9 → 0x00..0x09, A..Z → 0x0A..0x23)
+TOP_NONE = 0x00
+TOP_A    = 0x0A
+TOP_B    = 0x0B
+TOP_C    = 0x0C
+TOP_D    = 0x0D
+TOP_E    = 0x0E
+TOP_F    = 0x0F
+TOP_G    = 0x10
+TOP_H    = 0x11
+TOP_I    = 0x12
+TOP_J    = 0x13
+TOP_K    = 0x14
+TOP_L    = 0x15
+TOP_M    = 0x16
+TOP_N    = 0x17
+TOP_O    = 0x18
+TOP_P    = 0x19
+TOP_Q    = 0x1A
+TOP_R    = 0x1B
+TOP_S    = 0x1C
+TOP_T    = 0x1D
+TOP_U    = 0x1E
+TOP_V    = 0x1F
+TOP_W    = 0x20
+TOP_Y    = 0x22
+
+# Volume / pan column selectors (2-bit field at top of vol/pan byte)
+SEL_SET  = 0     # 6-bit value: set vol / pan
+SEL_UP   = 1     # 6-bit per-tick slide up / right
+SEL_DOWN = 2     # 6-bit per-tick slide down / left
+SEL_FINE = 3     # 1-bit dir + 5-bit magnitude, fired on tick 0
+
+# 12-TET semitone → Taud J-arpeggio byte (high byte of pitch delta).
+# byte = round(semitone * 4096 / 12 / 256) = round(semitone * 4 / 3).
+J_SEMI_TABLE = [0x00, 0x01, 0x03, 0x04, 0x05, 0x07, 0x08, 0x09,
+                0x0B, 0x0C, 0x0D, 0x0F, 0x10, 0x11, 0x13, 0x14]
+
+# Effect-letter indices (1-based; A=1..Z=26). Shared by s3m2taud and it2taud.
+EFF_A = 1;  EFF_B = 2;  EFF_C = 3;  EFF_D = 4;  EFF_E = 5
+EFF_F = 6;  EFF_G = 7;  EFF_H = 8;  EFF_I = 9;  EFF_J = 10
+EFF_K = 11; EFF_L = 12; EFF_M = 13; EFF_N = 14; EFF_O = 15
+EFF_P = 16; EFF_Q = 17; EFF_R = 18; EFF_S = 19; EFF_T = 20
+EFF_U = 21; EFF_V = 22; EFF_W = 23; EFF_X = 24; EFF_Y = 25
+EFF_Z = 26
+
+
+# ── Envelope offset minifloat ────────────────────────────────────────────────
+#
+# Mirror of tsvm_core/.../ThreeFiveMinifloat.kt — used by every *2taud
+# converter that emits envelope nodes. 3.5 unsigned minifloat (3-bit exponent
+# + 5-bit mantissa) rebiased so the smallest non-zero step is 1/256 s ≈ 3.91
+# ms and the maximum is 15.75 s. The previous bias (1/32-step, max 126 s)
+# under-resolved single-tick deltas at typical tracker BPMs. Every value here
+# is the original LUT divided by 8.
+
+MINUFLOAT_LUT = (
+    0.0, 0.00390625, 0.0078125, 0.01171875, 0.015625, 0.01953125, 0.0234375, 0.02734375,
+    0.03125, 0.03515625, 0.0390625, 0.04296875, 0.046875, 0.05078125, 0.0546875, 0.05859375,
+    0.0625, 0.06640625, 0.0703125, 0.07421875, 0.078125, 0.08203125, 0.0859375, 0.08984375,
+    0.09375, 0.09765625, 0.1015625, 0.10546875, 0.109375, 0.11328125, 0.1171875, 0.12109375,
+    0.125, 0.12890625, 0.1328125, 0.13671875, 0.140625, 0.14453125, 0.1484375, 0.15234375,
+    0.15625, 0.16015625, 0.1640625, 0.16796875, 0.171875, 0.17578125, 0.1796875, 0.18359375,
+    0.1875, 0.19140625, 0.1953125, 0.19921875, 0.203125, 0.20703125, 0.2109375, 0.21484375,
+    0.21875, 0.22265625, 0.2265625, 0.23046875, 0.234375, 0.23828125, 0.2421875, 0.24609375,
+    0.25, 0.2578125, 0.265625, 0.2734375, 0.28125, 0.2890625, 0.296875, 0.3046875,
+    0.3125, 0.3203125, 0.328125, 0.3359375, 0.34375, 0.3515625, 0.359375, 0.3671875,
+    0.375, 0.3828125, 0.390625, 0.3984375, 0.40625, 0.4140625, 0.421875, 0.4296875,
+    0.4375, 0.4453125, 0.453125, 0.4609375, 0.46875, 0.4765625, 0.484375, 0.4921875,
+    0.5, 0.515625, 0.53125, 0.546875, 0.5625, 0.578125, 0.59375, 0.609375,
+    0.625, 0.640625, 0.65625, 0.671875, 0.6875, 0.703125, 0.71875, 0.734375,
+    0.75, 0.765625, 0.78125, 0.796875, 0.8125, 0.828125, 0.84375, 0.859375,
+    0.875, 0.890625, 0.90625, 0.921875, 0.9375, 0.953125, 0.96875, 0.984375,
+    1.0, 1.03125, 1.0625, 1.09375, 1.125, 1.15625, 1.1875, 1.21875,
+    1.25, 1.28125, 1.3125, 1.34375, 1.375, 1.40625, 1.4375, 1.46875,
+    1.5, 1.53125, 1.5625, 1.59375, 1.625, 1.65625, 1.6875, 1.71875,
+    1.75, 1.78125, 1.8125, 1.84375, 1.875, 1.90625, 1.9375, 1.96875,
+    2.0, 2.0625, 2.125, 2.1875, 2.25, 2.3125, 2.375, 2.4375,
+    2.5, 2.5625, 2.625, 2.6875, 2.75, 2.8125, 2.875, 2.9375,
+    3.0, 3.0625, 3.125, 3.1875, 3.25, 3.3125, 3.375, 3.4375,
+    3.5, 3.5625, 3.625, 3.6875, 3.75, 3.8125, 3.875, 3.9375,
+    4.0, 4.125, 4.25, 4.375, 4.5, 4.625, 4.75, 4.875,
+    5.0, 5.125, 5.25, 5.375, 5.5, 5.625, 5.75, 5.875,
+    6.0, 6.125, 6.25, 6.375, 6.5, 6.625, 6.75, 6.875,
+    7.0, 7.125, 7.25, 7.375, 7.5, 7.625, 7.75, 7.875,
+    8.0, 8.25, 8.5, 8.75, 9.0, 9.25, 9.5, 9.75,
+    10.0, 10.25, 10.5, 10.75, 11.0, 11.25, 11.5, 11.75,
+    12.0, 12.25, 12.5, 12.75, 13.0, 13.25, 13.5, 13.75,
+    14.0, 14.25, 14.5, 14.75, 15.0, 15.25, 15.5, 15.75,
+)
+
+
+def nearest_minifloat(sec: float) -> int:
+    """Return the ThreeFiveMiniUfloat index (0..255) for the LUT entry nearest to `sec`."""
+    if sec <= 0.0:
+        return 0
+    if sec >= MINUFLOAT_LUT[-1]:
+        return 255
+    lo, hi = 0, len(MINUFLOAT_LUT) - 1
+    while lo < hi:
+        mid = (lo + hi) // 2
+        if MINUFLOAT_LUT[mid] < sec:
+            lo = mid + 1
+        else:
+            hi = mid
+    if lo > 0 and abs(MINUFLOAT_LUT[lo - 1] - sec) < abs(MINUFLOAT_LUT[lo] - sec):
+        return lo - 1
+    return lo
+
+
+# ── Helpers ──────────────────────────────────────────────────────────────────
+
+def d_arg_to_col(arg: int):
+    """Convert a two-nibble D-style vol/pan slide arg into a column override.
+
+    Returns (selector, value) or None for no-op. Volume column treats
+    selector 1 as up / 2 as down; pan column reuses 1 = right, 2 = left.
+    Both-nibbles-non-zero (and neither $F) is ambiguous; ST3/PT/IT all
+    prefer up.
+    """
+    if arg == 0:
+        return None
+    hi = (arg >> 4) & 0xF
+    lo = arg & 0xF
+    if hi == 0xF and lo > 0:
+        return (SEL_FINE, lo & 0x1F)              # fine slide down (dir bit 0)
+    if lo == 0xF and hi > 0:
+        return (SEL_FINE, (hi & 0x1F) | 0x20)     # fine slide up (dir bit 1)
+    if hi > 0 and lo == 0:
+        return (SEL_UP, hi)
+    if lo > 0 and hi == 0:
+        return (SEL_DOWN, lo)
+    return (SEL_UP, hi)
+
+
+def resample_linear(data: bytes, ratio: float) -> bytes:
+    """Resample bytes by ratio (< 1 = downsample) using linear interpolation."""
+    if not data:
+        return data
+    n_out = max(1, int(len(data) * ratio))
+    out   = bytearray(n_out)
+    for i in range(n_out):
+        src  = i / ratio
+        i0   = int(src)
+        frac = src - i0
+        i1   = min(i0 + 1, len(data) - 1)
+        v    = data[i0] * (1.0 - frac) + data[i1] * frac
+        out[i] = int(v + 0.5) & 0xFF
+    return bytes(out)
+
+
+def rescale_offset_effects(pat_bin: bytes, ratio: float) -> bytes:
+    """Scale TOP_O sample-offset args in raw pattern bytes by `ratio`.
+
+    Each row is 8 bytes; byte 5 is the effect opcode, bytes 6-7 are the
+    little-endian 16-bit arg (= byte offset into the sample). When the
+    sample bin overflows and every sample is downsampled globally, the
+    offset commands must shrink the same amount or O-jumps land past
+    the new end of sample.
+    """
+    if ratio == 1.0 or not pat_bin:
+        return pat_bin
+    out = bytearray(pat_bin)
+    for i in range(0, len(out) - 7, 8):
+        if out[i + 5] == TOP_O:
+            arg = out[i + 6] | (out[i + 7] << 8)
+            arg = max(0, min(0xFFFF, int(arg * ratio + 0.5)))
+            out[i + 6] = arg & 0xFF
+            out[i + 7] = (arg >> 8) & 0xFF
+    return bytes(out)
+
+
+def rescale_offset_effects_per_slot(pat_bin: bytes,
+                                     num_cues: int,
+                                     num_channels: int,
+                                     slot_ratios: dict) -> bytes:
+    """Scale TOP_O args using a per-slot ratio map.
+
+    `pat_bin` is laid out as `num_cues × num_channels` consecutive
+    PATTERN_BYTES (=512) blocks, channel-minor within each cue. For each
+    channel, walk the rows in cue order and track the most recently
+    written slot byte (row offset 2). When a TOP_O effect appears, scale
+    its arg by `slot_ratios[active_slot]`, falling back to ratio 1.0 if
+    the slot is unknown (e.g. row hits an O before any inst byte has
+    selected a sample for the channel).
+    """
+    if not pat_bin or not slot_ratios:
+        return pat_bin
+    if all(r == 1.0 for r in slot_ratios.values()):
+        return pat_bin
+    out = bytearray(pat_bin)
+    active = [0] * num_channels
+    for cue in range(num_cues):
+        for ch in range(num_channels):
+            block = (cue * num_channels + ch) * PATTERN_BYTES
+            for row in range(PATTERN_ROWS):
+                rb = block + row * 8
+                inst = out[rb + 2]
+                if inst != 0:
+                    active[ch] = inst
+                if out[rb + 5] == TOP_O:
+                    ratio = slot_ratios.get(active[ch], 1.0)
+                    if ratio != 1.0:
+                        arg = out[rb + 6] | (out[rb + 7] << 8)
+                        arg = max(0, min(0xFFFF, int(arg * ratio + 0.5)))
+                        out[rb + 6] = arg & 0xFF
+                        out[rb + 7] = (arg >> 8) & 0xFF
+    return bytes(out)
+
+
+def encode_cue(patterns12: list, instruction) -> bytearray:
+    """Encode a 32-byte cue entry for up to 20 voices with 12-bit pattern numbers.
+
+    `instruction` is either an int (legacy single-byte value placed at byte 30,
+    byte 31 = 0) or a 2-tuple `(byte30, byte31)` for two-byte forms such as
+    LEN (CUE_INST_LEN with row count - 1).
+    """
+    pats = list(patterns12) + [0xFFF] * NUM_VOICES
+    pats = pats[:NUM_VOICES]
+    entry = bytearray(CUE_SIZE)
+    for i in range(10):      # 10 bytes: 2 voices per byte
+        v0, v1 = pats[i*2], pats[i*2+1]
+        entry[i]      = ((v0 & 0xF) << 4) | (v1 & 0xF)               # low nybbles
+        entry[10 + i] = (((v0 >> 4) & 0xF) << 4) | ((v1 >> 4) & 0xF) # mid nybbles
+        entry[20 + i] = (((v0 >> 8) & 0xF) << 4) | ((v1 >> 8) & 0xF) # high nybbles
+    if isinstance(instruction, tuple):
+        b30, b31 = instruction
+        entry[30] = b30 & 0xFF
+        entry[31] = b31 & 0xFF
+    else:
+        entry[30] = instruction & 0xFF
+    return entry
+
+
+def cue_instruction_len(rows: int) -> tuple:
+    """Build the 2-byte LEN cue instruction for `rows` (1..64).
+
+    Returns (byte30, byte31) where byte30 = 0x02 and byte31 = (rows - 1) & 0x3F.
+    """
+    if not 1 <= rows <= 64:
+        raise ValueError(f"LEN row count must be 1..64, got {rows}")
+    return (CUE_INST_LEN, (rows - 1) & 0x3F)
+
+
+def deduplicate_patterns(pat_bin: bytes, num_pats: int) -> tuple:
+    """Consolidate identical 512-byte Taud patterns into a single copy.
+
+    Returns (deduped_bin, remap, num_unique) where remap[original_idx] =
+    canonical_idx.
+    """
+    seen = {}
+    remap = {}
+    canonical = []
+    for i in range(num_pats):
+        pat = pat_bin[i * PATTERN_BYTES : (i + 1) * PATTERN_BYTES]
+        if pat in seen:
+            remap[i] = seen[pat]
+        else:
+            ci = len(canonical)
+            seen[pat] = ci
+            remap[i] = ci
+            canonical.append(pat)
+    return b''.join(canonical), remap, len(canonical)
+
+
+def encode_song_entry(song_offset: int, num_voices: int, num_patterns: int,
+                      bpm_stored: int, tick_rate: int,
+                      base_note: int, base_freq: float, flags_byte: int,
+                      pat_bin_comp_size: int, cue_sheet_comp_size: int,
+                      global_vol: int = 0x80, mixing_vol: int = 0x80) -> bytes:
+    """Pack a 32-byte Taud song table entry.
+
+    Layout:
+        u32 song_offset, u8 num_voices, u16 num_patterns,
+        u8 bpm_stored, u8 tick_rate,
+        u16 base_note, f32 base_freq,
+        u8 flags, u8 global_vol, u8 mixing_vol,
+        u32 pat_bin_comp_size, u32 cue_sheet_comp_size,
+        byte[6] reserved.
+    """
+    entry = struct.pack('<IBHBBHfBBBII',
+        song_offset,
+        num_voices & 0xFF,
+        num_patterns & 0xFFFF,
+        bpm_stored & 0xFF,
+        tick_rate & 0xFF,
+        base_note & 0xFFFF,
+        float(base_freq),
+        flags_byte & 0xFF,
+        global_vol & 0xFF,
+        mixing_vol & 0xFF,
+        pat_bin_comp_size & 0xFFFFFFFF,
+        cue_sheet_comp_size & 0xFFFFFFFF,
+    ) + b'\x00' * 6
+    assert len(entry) == TAUD_SONG_ENTRY
+    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
+PROJECT_DATA_HEADER_SIZE = 16   # 8-byte magic + 8 reserved
+
+
+def _name_table_blob(names) -> bytes:
+    """Encode a list of names (slot-indexed; slot 0 is left empty in source) as
+    0x1E-separated UTF-8 bytes. Trailing empty slots are trimmed to save space.
+    Returns b'' when every name is empty.
+    """
+    if not names:
+        return b''
+    end = len(names)
+    while end > 0 and not names[end - 1]:
+        end -= 1
+    if end == 0:
+        return b''
+    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,
+                       ixmp_patches=None) -> bytes:
+    """Build the optional PROJECT DATA section payload.
+
+    Returns the full block (8-byte magic + 8 reserved bytes + concatenated
+    FourCC sections), or b'' when there's nothing to write so the caller can
+    leave the header's projOff field at zero.
+
+    `sample_names` / `instrument_names` / `pattern_names` are slot-indexed
+    lists (entry 0 is typically empty since slot 0 is reserved); they are
+    encoded as 0x1E-separated UTF-8 strings inside SNam / INam / pNam blocks.
+
+    `song_metadata` is an optional list of dicts, one per song:
+        { 'index': int (0..255),
+          'notation': int = 0,
+          'beat_pri': int = 4,
+          'beat_sec': int = 16,
+          'name': str = '',
+          'composer': str = '',
+          'copyright': str = '' }
+    """
+    sections = []
+
+    def add(fourcc: bytes, payload: bytes) -> None:
+        if not payload:
+            return
+        sections.append(fourcc + struct.pack('<I', len(payload)) + payload)
+
+    if project_name:
+        add(b'PNam', project_name.encode('utf-8', 'replace'))
+    if author:
+        add(b'PCom', author.encode('utf-8', 'replace'))
+    if copyright_str:
+        add(b'PCpr', copyright_str.encode('utf-8', 'replace'))
+
+    add(b'INam', _name_table_blob(instrument_names))
+    add(b'SNam', _name_table_blob(sample_names))
+    add(b'pNam', _name_table_blob(pattern_names))
+
+    if song_metadata:
+        smet = bytearray()
+        for entry in song_metadata:
+            idx      = entry.get('index', 0) & 0xFF
+            notation = entry.get('notation', 0) & 0xFFFF
+            beat_pri = entry.get('beat_pri', 4) & 0xFF
+            beat_sec = entry.get('beat_sec', 16) & 0xFF
+            name_b = entry.get('name', '').encode('utf-8', 'replace') + b'\x00'
+            comp_b = entry.get('composer', '').encode('utf-8', 'replace') + b'\x00'
+            copr_b = entry.get('copyright', '').encode('utf-8', 'replace') + b'\x00'
+            payload = (struct.pack('<HBB', notation, beat_pri, beat_sec)
+                       + name_b + comp_b + copr_b)
+            smet.append(idx)
+            smet += struct.pack('<I', len(payload))
+            smet += payload
+        add(b'sMet', bytes(smet))
+
+    if ixmp_patches:
+        add(b'Ixmp', encode_ixmp_payload(ixmp_patches))
+
+    if not sections:
+        return b''
+
+    return PROJECT_DATA_MAGIC + b'\x00' * 8 + b''.join(sections)
+
+
+# ── Sample normalisation ─────────────────────────────────────────────────────
+
+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.
+
+    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 = []
+    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*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*2)[0]
+            v = (s >> 8) + 128
+        else:
+            if is_stereo:
+                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
+        out.append(v & 0xFF)
+    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.
@@ -1973,59 +1979,473 @@ A universal, simple cue designed to work as both playlist to cue up external fil
 
 --------------------------------------------------------------------------------
 
-**Sound Adapter**
+**Audio Adapter**
 
 Endianness: little
 
 
-TSVM Sound Adapter is consisted of 4 playheads, each playhead is capable of playing one PCM or Tracker track.
+TSVM Audio Adapter is consisted of 4 playheads, each playhead is capable of playing one PCM or Tracker track.
 
 Synchronisation between playheads are not guaranteed. Do not play music in multiple tracks.
 
 
 Memory Space
 
-0..770047 RW: Sample bin (752k)
-770048..786431 RW: Instrument bin (256 instruments, 64 bytes each; instrument 0 does nothing; 16k)
+0..524287 RW: Sample bin window (512k)
+720896..786431 RW: Instrument bin (256 instruments, 256 bytes each; instrument 0 does nothing; 64k)
 786432..851967 RW: Play data 1 (currently exposed bank; 64k)
 851968..917503 RW: Play data 2 (currently exposed bank; 64k)
 917504..983039 RW: TAD Input Buffer (64k)
 983040..1048575 RW: TAD Decode Output (64k)
 
-Sample bin: just raw sample data thrown in there. You need to keep track of starting point for each sample
+Sample bin: just raw sample data thrown in there. You need to keep track of starting point for each sample. Actual sample memory is 8 MB and are banked. Write to MMIO address 46 to switch banks.
 
 Instrument bin: Registry for 256 instruments, formatted as:
-    Uint16 Sample Pointer
-    Uint16 Sample length
-    Uint16 Sampling rate at C3 (note number 0x4000)
-    Uint16 Play Start (usually 0 but not always)
-    Uint16 Loop Start (can be smaller than Play Start)
-    Uint16 Loop End
-     Bit32 Flags
-        0b hhhh 00pp
-            h: sample pointer high bit
+
+The instrument record is 256 bytes wide. Envelopes are described by FOUR
+independent regions per envelope (vol / pan / pitch-filter):
+    1. The 25 envelope nodes (offsets 21 / 71 / 121).
+    2. The LOOP word (offsets 15 / 17 / 19) — defines an always-active
+       wrap region. When enabled (b=1) and the envelope position reaches
+       loop_end, it wraps back to loop_start. Active regardless of key
+       state. This is the IT/FT2 envelope loop.
+    3. The SUSTAIN word (offsets 189 / 191 / 193) — defines a wrap
+       region that is ONLY active while the key is on. When the key
+       goes off the sustain "releases" and the envelope position is
+       free to walk past sus_end. Concretely:
+         - FT2-style "sustain point": store sus_start == sus_end (single
+           index). Engine wraps that index → itself, so the envelope
+           holds at the point until key-off.
+         - IT-style "sustain loop":  store sus_start <= sus_end. Engine
+           wraps sus_end → sus_start while key is on, so the envelope
+           loops within the sustain range until key-off.
+    4. (none — there is no separate "release loop"; once sustain releases
+       the envelope walks forward and is captured by the LOOP region if
+       the LOOP region exists and the position enters it.)
+
+Priority during playback follows schismtracker player/sndmix.c:480-499:
+    if SUSTAIN.b == 1 and !key_off : wrap (sus_start, sus_end)
+    elif LOOP.b == 1               : wrap (loop_start, loop_end)
+    else                           : hold at last node
+
+This means SUSTAIN takes precedence over LOOP while the key is on; once
+the key is released, LOOP becomes the active wrap region. Setting both
+to b=0 disables envelope wrapping entirely (envelope plays once and holds
+at its last node).
+
+The b flag is the SOLE enable bit for each region; the historical 't'
+(sustain breaks on key-off) and 'u' (sustain/loop enable) flags are NOT
+present in this encoding — sustain vs loop is now a structural
+distinction (different word at a different offset), not a flag bit.
+
+Envelope PRESENCE — distinct from LOOP/SUSTAIN enable — is signalled by
+the `P` bit at LOOP-word bit 13 (the high byte's bit 5; offsets 16/18/20
+bit 5). Added 2026-05-06 to disambiguate two cases that the wrap-enable
+bits cannot tell apart on their own:
+    P=0: the source had no envelope of this kind. Engine ignores the
+         node array entirely and the mixer skips envelope-driven output
+         for this voice (pan reads from channelPan only, cutoff/pitch
+         reads from sample defaults only). The 25 node slots may still
+         be left as default-fill garbage; nothing reads them.
+    P=1: envelope is defined. Engine evaluates the nodes every tick.
+         Wrap behaviour is independently controlled by LOOP.b and
+         SUSTAIN.b — when both are 0 the envelope walks once forward
+         and holds at its terminator (the IT idiom for envelope-driven
+         decay tails / shaped attacks).
+The P bit was introduced to fix a gating ambiguity for pan and pitch/
+filter envelopes: the engine could not distinguish "no envelope at all"
+(treat as absent) from "envelope present but neither LOOP nor SUSTAIN
+wrap is enabled" (evaluate and apply, just don't wrap). Volume envelope
+evaluation has always been unconditional in the engine (a default
+single-point envelope at value 63 is harmlessly held at unity), so
+P_vol is currently informational only — converters should still set it
+when the source defines a volume envelope, for consistency and to
+support future per-voice gating.
+
+P is the SOLE presence signal: converters MUST set P=1 whenever they
+emit envelope nodes, regardless of whether the source enables LOOP or
+SUSTAIN. Pre-2026-05-06 .taud files predate the P bit and will not have
+their pan / pf envelopes evaluated by the current engine — re-convert
+from source.
+
+0   Uint32 Sample Pointer
+4   Uint16 Sample length
+6   Uint16 Sampling rate at C4 (note number 0x5000)
+8   Uint16 Play Start (usually 0 but not always)
+10  Uint16 Loop Start (can be smaller than Play Start)
+12  Uint16 Loop End
+14  Bit8   Sample Flags
+        0b 0000 0spp
            pp: loop mode. 0-no loop, 1-loop, 2-backandforth, 3-oneshot (ignores note length unless overridden by other notes)
-  Bit16x24 Volume envelopes
-       Byte 1: Volume
-       Byte 2: Second offset from the prev point, in 3.5 Unsigned Minifloat
+           s: loop is sustain (key-off escapes the loop)
+            - IT: look for sample's SusLoop flag
+15  Bit16  Volume envelope LOOP word
+        * Always-active wrap region for the volume envelope. See SUSTAIN word at offset 189 for the key-on-only wrap.
+        * IMPORTANT: the `b` bit gates only the LOOP wrap behaviour. The volume
+          envelope itself is always evaluated whenever the per-voice volume-envelope
+          toggle is on (default true on note-on; switched by effect S $7x / S $8x).
+          This matches IT/Schism (player/sndmix.c:470-502): CHN_VOLENV is independent
+          of ENV_VOLLOOP / ENV_VOLSUSTAIN. An envelope with no LOOP and no SUSTAIN
+          (both `b` bits = 0) walks once from start to its terminator and holds —
+          which is the IT idiom for envelope-driven decay tails.
+        * The cut rule: when the volume envelope walks past the last real node in
+          fall-through (no active sustain or loop wrap) AND that node's value is 0,
+          the engine deactivates the voice (player/sndmix.c:493-498). Without this,
+          instruments with stored fadeout=0 + envelope ending at 0 would silently
+          hold their voices forever.
+        0b 00P_sssss_0cb_eeeee
+            s (bits 12..8) : loop start index (0..24)
+            e (bits 4..0)  : loop end   index (0..24)
+            b (bit 5)      : enable the LOOP wrap (0 = envelope walks once to its
+                             terminator and holds; non-zero loops between s and e)
+            c (bit 6)      : envelope carry (cross-trigger envelope position carry)
+            P (bit 13)     : envelope present in source (informational for vol —
+                             engine evaluates vol env unconditionally; converters
+                             should set P=1 when emitting nodes for consistency
+                             with pan/pf envelopes, see file-header preamble)
+            (bits 7, 14..15 reserved — set to 0)
+17  Bit16  Panning envelope LOOP word
+        * Always-active wrap region for the pan envelope.
+        0b 00P_sssss_pcb_eeeee
+            s (bits 12..8) : loop start index
+            e (bits 4..0)  : loop end   index
+            b (bit 5)      : enable the LOOP
+            c (bit 6)      : envelope carry
+            p (bit 7)      : use default pan (see offset 177 "Default pan value" below).
+                              Independent of LOOP enable; the engine reads this bit
+                              from the LOOP word as the canonical home for envelope-
+                              level meta flags.
+            P (bit 13)     : envelope present in source. Gates whether the mixer
+                             applies envelope-driven pan at all. P=0 ⇒ mixer uses
+                             channelPan only and the node array is ignored. P=1 ⇒
+                             evaluate every tick, even when both LOOP.b and SUSTAIN.b
+                             are 0 (envelope walks once and holds — IT pan-env
+                             flag=0x01 idiom).
+            (bits 14..15 reserved)
+19  Bit16  Pitch/Filter envelope LOOP word
+        * Always-active wrap region for the pitch/filter envelope.
+        0b 00P_sssss_mcb_eeeee
+            s (bits 12..8) : loop start index
+            e (bits 4..0)  : loop end   index
+            b (bit 5)      : enable the LOOP
+            c (bit 6)      : envelope carry
+            m (bit 7)      : mode — 0 = pitch envelope, 1 = filter envelope
+            P (bit 13)     : envelope present in source. Same semantics as the
+                             pan envelope's P bit: gates whether the mixer applies
+                             envelope-driven pitch / cutoff at all. P=0 ⇒ no
+                             envelope contribution (sample plays at its own pitch /
+                             default cutoff). P=1 ⇒ evaluate every tick regardless
+                             of LOOP.b / SUSTAIN.b.
+            (bits 14..15 reserved)
+21  Bit16x25 Volume envelopes
+       Byte 1: Volume (00..3F)
+       Byte 2: Time until the next point, in seconds (3.5 Unsigned Minifloat, biased; range 0..15.75 s, smallest non-zero step 1/256 s ≈ 3.91 ms — chosen so single tracker ticks resolve at every supported BPM). 0 = hold at this point indefinitely.
+71  Bit16x25 Panning envelopes
+      Byte 1: Pan (00..FF)
+      Byte 2: Time until the next point, in seconds (3.5 Unsigned Minifloat, biased; range 0..15.75 s, smallest non-zero step 1/256 s ≈ 3.91 ms — chosen so single tracker ticks resolve at every supported BPM). 0 = hold at this point indefinitely.
+121 Bit16x25 Pitch/Filter envelopes
+      Byte 1: Value (00..FF)
+      Byte 2: Time until the next point, in seconds (3.5 Unsigned Minifloat, biased; range 0..15.75 s, smallest non-zero step 1/256 s ≈ 3.91 ms — chosen so single tracker ticks resolve at every supported BPM). 0 = hold at this point indefinitely.
+171 Uint8  Instrument Global Volume (0..255)
+        * 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 — 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:
+              taud_igv = round(inst.gv * sample.gv * 255 / (128 * 64))
+          The samplewise `sample.vol` (0..64) is NOT folded here — it is the
+          per-trigger default chan_volume in IT (replaceable by V column),
+          and Taud carries it in byte 196 ("Default Note Volume"). Folding
+          it here was the cause of the "low-number voleffs are too quiet"
+          regression (TODO §2350, fixed 2026-05-09).
+        * FastTracker2 has range of 0..64 with no instrumentwise multiplier
+          beyond it; multiply by (255/64) and round. The XM samplewise
+          volume goes into byte 196.
+172 Uint8  Volume Fadeout low bits
+173 Bit8   Volume Fadeout high bits
+        0b 0000 ffff
+            f: Volume Fadeout high bits (low nibble of byte 173; high nibble reserved, must be zero)
+        * Combined 12-bit unsigned value (range 0..4095). The engine maintains
+          a per-voice fadeoutVolume ∈ [0, 1] initialised to 1.0 on note-on, and
+          while the voice is in key-off or NNA Note-Fade state applies once per
+          song tick:
+              fadeoutVolume -= storedFadeout / 1024.0
+              clamp fadeoutVolume to [0, 1]
+              if fadeoutVolume == 0: voice deactivates
+          The voice's amplitude is multiplied by fadeoutVolume each tick.
+        * Stored value semantics (no separate "use fadeout" flag — like IT and
+          FT2 file formats, "no fade" and "instant cut" are both encoded as
+          extreme values of this same field):
+            - 0          : no fade. fadeoutVolume never moves; the voice plays
+                           at envelope-driven volume indefinitely. Termination
+                           must come from the volume envelope reaching a final
+                           0-valued node, the sample ending, or a note-cut.
+            - 1..1023    : graduated fade. Completes in (1024 / storedFadeout)
+                           ticks. e.g. 1 → 1024 ticks; 32 → 32 ticks.
+            - 1024       : exact 1-tick cut. fadeoutVolume goes 1.0 → 0.0 in
+                           one tick (the canonical "kill on key-off" value).
+            - 1025..4095 : also a 1-tick cut (clamped at 0). The 4× headroom
+                           over 1024 lets converters carry out-of-spec source
+                           values without saturating prematurely.
+        * Tick-rate worked example at default 50 Hz (BPM 125, speed 6):
+            - storedFadeout = 1    → fade ≈ 20.5 s
+            - storedFadeout = 32   → fade ≈ 640 ms
+            - storedFadeout = 1024 → ~20 ms (one tick)
+        * Source-format mapping (converters scale source units → Taud field):
+            - IT: 16-bit field at IT instrument record offset 0x14, range
+              0..1024 per ITTECH (some loaders accept up to 2048). Schism's
+              per-tick decrement is stored / 1024 of unit volume — identical
+              to Taud's unit. Pass-through with clamp:
+                  taud_fadeout = min(it_fadeout & 0xFFFF, 0x0FFF)
+            - FT2/XM: 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 of unit volume — to match Taud's stored / 1024
+              rate, divide source by 32 (round-to-nearest):
+                  taud_fadeout = min((xm_fadeout + 16) // 32, 0x0FFF)
+              XM stored 1..15 round to Taud 0 (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: no instrument-level fadeout in source; converters
+              write 0 (notes retire on sample-end or pattern note-cut).
+174 Uint8  Volume swing (0..255 full range)
+175 Uint8  Vibrato speed
+        * ImpulseTracker has samplewise vibrato speed (0..64), and they must be taken into account because Taud has no samplewise config
+        * FastTracker2 has instrumentwise config (0..255)
+        * The spec follows FastTracker2, and conversion must be performed when importing from FastTracker2
+176 Uint8  Vibrato sweep
+        * FastTracker2 instrument config
+177 Uint8  Default pan value (0..255 full range, see offset 17 for the enable flag)
+        * ImpulseTracker has samplewise default pan and instrumentwise default pan, and they must be taken into account because Taud has no samplewise config
+178 Uint16 Pitch-pan centre (4096-TET note value)
+180 Sint8  Pitch-pan separation (-128..127 full range)
+181 Uint8  Pan swing (0..255 full range)
+182 Uint8  Default cutoff (0..254 full range, 255 to off (-1 on IT). Effect range equals to that of ImpulseTracker -- 127 in IT is equal to 254 in Taud)
+183 Uint8  Default resonance (0..254 full range, 255 to off (-1 on IT). Effect range equals to that of ImpulseTracker -- 127 in IT is equal to 254 in Taud)
+184 Uint16 Sample detune (in 4096-TET unit) (FT2 finetune scale need to be rescaled accordingly)
+186 Bit8   Instrument Flag
+        0b 000 www nn
+            n: New note action. 00: note off, 01: note cut, 10: continue, 11: note fade (arranged differently to IT)
+            ww: Vibrato waveform (IT: sample config, FT2: instrument config). 00: sine, 01: ramp-down saw, 10: square, 11: random, 100: ramp-up saw (FT2 only)
+187 Uint8  Vibrato Depth (0..255 full range)
+        * ImpulseTracker has range of 0..32 ON THE SAMPLE SETTINGS; multiply by (255/32) then round to int
+        * FastTracker2 has range of 0..16; multiply by (255/16) then round to int
+188 Uint8  Vibrato Rate (0..255 full range)
+        * ImpulseTracker sample config. The spec follows ImpulseTracker precisely
+189 Bit16  Volume envelope SUSTAIN word
+        * Wrap region active ONLY while key is on. Released on key-off.
+        * FT2 single-point sustain: store sus_start == sus_end (the engine
+          wraps that index → itself, so the envelope holds there).
+        * IT sustain loop: store sus_start <= sus_end (engine wraps the range
+          while key is on; same shape as the LOOP word).
+        0b 000_sssss_00b_eeeee
+            s (bits 12..8) : sustain start index (0..24)
+            e (bits 4..0)  : sustain end   index (0..24)
+            b (bit 5)      : enable the SUSTAIN (0 = no sustain wrap)
+            (bits 6..7, 13..15 reserved — the 'c' carry bit lives in the LOOP word)
+191 Bit16  Panning envelope SUSTAIN word
+        * Same encoding as offset 189, applied to the pan envelope.
+        0b 000_sssss_00b_eeeee
+193 Bit16  Pitch/Filter envelope SUSTAIN word
+        * Same encoding as offset 189, applied to the pitch/filter envelope.
+        0b 000_sssss_00b_eeeee
+195 Bit8   Duplicate Check / Action (IT-only; FT2 leaves this 0)
+        0b 0000 dcdt
+            dt (bits 0..1) : Duplicate Check Type. 0=off, 1=note, 2=sample, 3=instrument.
+            dc (bits 2..3) : Duplicate Check Action. 0=note cut, 1=note off, 2=note fade.
+        * Relocated from offset 189 (which is now the volume sustain word) on 2026-05-06.
+        * 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 (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
+              instruments on the same channel can therefore have asymmetric duplicate
+              behaviour — IT-correct.
+            - Targets: the foreground voice on the same channel AND every background
+              (NNA-ghost) voice spawned earlier from that channel. Each is checked
+              independently against the new (instrument, note) pair.
+            - DCT match conditions:
+                  off (0)        : never matches; DCA never fires
+                  note (1)       : same noteVal AND same instrumentId
+                  sample (2)     : same instrumentId AND same canonical sample (matched
+                                   by samplePtr + sampleLength)
+                  instrument (3) : same instrumentId
+            - DCA actions on a matching voice:
+                  note cut (0)   : fadeoutVolume := 0; voice deactivates this tick
+                  note off (1)   : keyOff := true (sustain releases; volume envelope
+                                   continues past the sustain point; if the instrument
+                                   carries a non-zero fadeout, the fadeout decay starts
+                                   per byte 172/173 semantics)
+                  note fade (2)  : noteFading := true (begin fadeout immediately, no
+                                   sustain release — sample/envelope loops continue)
+            - Order with NNA: applyDuplicateCheck → maybeSpawnBackgroundForNNA →
+              triggerNote. So when DCA flags the foreground voice, the NNA-ghost it
+              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 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 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
+            - S3M: taud_dnv = round(min(inst.volume, 64) * 255 / 64)
+            - MOD: taud_dnv = round(min(sample.volume, 64) * 255 / 64)
+        * .taud files written before 2026-05-09 stored sample.vol folded into
+          byte 171 (IGV) and left this byte zero. Engines reading those older
+          files SHOULD treat default_note_volume == 0 as "field not present"
+          and fall back to row_default = 63 — preserving the pre-fix behaviour
+          for legacy files where IGV already carries sample.vol.
+197..255 Reserved (59 bytes free for future per-instrument fields)
+
+
+
+TODO:
+    [x] implement Instrument Flag, Vibrato Depth, Vibrato Rate, other samplewise/instrumentwise changes to it2taud and audio engine
+    [x] implement new note action on the audio engine (IT uses "background channels", maybe we can do the same but make "background channels" mixer-private)
+    [x] (same context as above) implement S7x command
+    [x] on playback, panning changes randomly on Taud made by s3m2taud.py and mod2taud.py, but not by it2taud.py (maybe something's off with the instrument exports?)
+    [x] NNA not disabled for S3M and MOD
+    [x] `S B000` and `S B100` not working as intended -- on first playback it jumps to the next cue same row, on subsequent playbacks the commands are completely ignored
+    [x] implement S6x command
+    [x] implement Wxx command (global volume slide)
+    [x] implement sample loop sustain
+        "Caveat: on a foreground voice, key-off (row.note == 0x0000) currently sets voice.active = false at AudioAdapter.kt:1713, which silences the channel immediately. Sustain-loop escape therefore only takes effect on background voices spawned by NNA "Note Off" — which matches the IT idiom of layering a new note over a sustained one. Let me know if you also want the foreground key-off to keep the voice playing through fadeout."
+    [x] cue and pattern compression of the Taud format (taud_common.py, taud.mjs)
+    [x] figure out how IT (0..256) and FT2 (0..FFF + cut) handles volume fadeout numbers, and come up with a compatible Taud spec, then implement
+    [x] Pitchbend on Amiga frequency mode sometimes works right, sometimes works wrong. (effect underdelivers) Affects every song with Amiga picth mode, AND ON THE fresh taut.js session only
+    [x] Fix 4THSYM.it filters
+    [x] 4THSYM.it: pitchbend is wrong, some notes keep playing (loudly!) even if new notes are emitted
+    [x] `*2taud.py`: some notes are emitted with wrong volume-set command. Tested with GSLINGER.mod: on order 0x15 channel 1, mod2taud.py emits volume 8 -- also many of the effects are dropped. Suggested solution: currently all converters write default volume to the voleff when original modules (.mod/.s3m/.it) specify nothing; we should also write nothing and let the engine resolve the value just like other trackers do (also we now have "Instrument Global Volume" on instrument definition unlike the other time). This bug may affecting other formats, not just mod2taud.py, as well
+    [x] nearly_there_.mod: `C#5 SD300 / ... / C-5 SD200 / A#4 / G#4 (at tickspeed 4)`: every `C-5 SD200` (there are four occurances) gets skipped
+    [x] scale Oxxxx when samples get resampled
+    [x] implement bitcrusher and overdrive  (eff sym '8' and '9')
+    [x] note trigger with inst and note fx set (e.g. portamento) but no volume set is not getting their default volume but getting what was before instead (SATELL.taud ptn 23) -- and simulateRowState() of taut.js always shows old volume instead of default volume, regardless of note fx's existence
+    [x] how does fadeout=0 work on IT? On XM, the note don't decay at all (that's why there's separate CUT value). Also see what Global Behaviour 'm' flag actually do on Taud (or, which slop AI had fed me *sigh*). `slumberjack.xm` plays normally but notes of `4THSYM.it` don't decay at all
+        Resolution: confirmed against schismtracker (player/sndmix.c:330-342) and
+        ft2-clone (src/ft2_replayer.c:1467-1481). Both IT and FT2 treat stored
+        fadeout=0 as "no fade" — there is no separate "use fadeout" flag in
+        either file format; "cut" is just the slider-extreme of the same
+        magnitude (MilkyTracker SectionInstruments.cpp:499-500 maps the slider's
+        4097th position to internal 32767). The 'm' flag's claim that FT2 cuts
+        on key-off when fadeout=0 was AI slop. Dropped the flag entirely; the
+        engine now uses a single divisor (1024) and converters scale their
+        source units to match (IT pass-through, XM ÷32). See byte 172-173 of
+        the instrument record for engine semantics.
+        Subsequent fixes for the 4THSYM.it hang:
+        (1) Implemented Schism's envelope-end + last-value-0 ⇒ cut rule
+            (player/sndmix.c:493-498) in AudioAdapter.kt advanceEnvelope.
+        (2) Volume envelope evaluation ungated from LOOP/SUSTAIN `b` bits.
+            IT envelopes with flags=0x01 (enabled-no-loop-no-sustain) had been
+            skipped because vEnvActive required either b bit. Now evaluation
+            is gated only by voice.volEnvOn (matches CHN_VOLENV in Schism).
+            See byte 15 spec for the LOOP word.
+    [x] Same gate fix needed for pan and pitch/filter envelopes.
+        Resolution (2026-05-06): added P (envelope present) bit at LOOP-word
+        bit 13 (offsets 16/18/20 bit 5) for all three envelopes. Engine
+        gates pan/pf envelope evaluation on P alone; converters set P=1
+        whenever they emit envelope nodes, regardless of LOOP/SUSTAIN
+        enable, so an enabled-no-wrap envelope (IT pan-env flag=0x01)
+        animates correctly. Mixer's hasPanEnv/hasPfEnv read the same gate,
+        so absent envelopes still bypass envelope-driven output. Pre-
+        2026-05-06 .taud files predate the P bit and need re-conversion
+        for pan/pf envelopes to play. See byte 15/17/19 spec for the LOOP
+        word bit layout.
+    [x] slumberjack.xm: E6x commands are not processed
+    [x] implement linear-freq tone mode (MONOTONE compat)
+        Resolution: ff=2 in song-table flags byte (was reserved). E / F / G
+        arguments are interpreted as Hz/tick at A4 = 440 Hz / C4 ≈ 261.6256 Hz
+        reference, exactly matching MONOTONE's MT_PLAY.PAS `Frequency`
+        arithmetic (MTSRC/MT_PLAY.PAS:606-630). Per-voice `linearFreq` cache
+        in AudioAdapter.kt preserves sub-noteVal precision across ticks; the
+        Voice cache reseeds on note trigger, fine slides, S$2x finetune, and
+        the start of a fresh multi-tick coarse slide. mon2taud.py now emits
+        Hz values verbatim (no SLIDE_UNITS_PER_HZ scaling) and sets the
+        linear-freq flag in the song-table flags byte. Spec details in
+        TAUD_NOTE_EFFECTS.md §1, §E, §F, §G.
+    [x] milkytracker-style volume ramping (on sample-end only)
+    [x] make Cues tab move faster
+        Resolution: Cues panel now uses memory-shift (`shiftOrdersAreaHorizontal`)
+        for LEFT/RIGHT and `shiftPatternArea` for UP/DOWN, plus per-row
+        (`drawOrdersRowAt`) and per-column (`drawOrdersVoiceColumnAt`) helpers,
+        replacing the full-panel redraw on every keystroke.
+    [x] volume and panning policy to match note effect policy: when note is "retriggerred" (note command with instrument specified), the volume/pan must take default value; if not (note command with instrument 0) the volume/pan must stay at the old value. Make both audio engine and taut.js simulator changes.
+    [x] xm volume column commands (+x, -x, Dx, Lx, Mx, Px, Rx, Sx, Ux, Vx) are completely ignored
+    [x] theday.xm order 0x28, channel 6..8 has 'note trigger with inst 1 but no volume -> key-off -> set-volume to 0x20 -> key-off -> set-volume to 0x10 -> key-off -> ...' and it sounds like gating: key-off silences the output, set-volume turns on the output again; notably, this behaviour only works when volume envelope is turned off (any fadeouts progress normally). FT2's keyOff (ft2_replayer.c:411-435) zeroes realVol/outVol when the volume envelope is disabled — IT/Schism does not, and Taud's engine follows IT semantics (no fade when fadeStep == 0). Resolved in xm2taud.py: a pre-pass tracks per-channel bound XM instrument across the order-list walk, and any key-off cell whose bound instrument has vol_env_type & XM_ENV_ON == 0 is paired with `SEL_SET vol=0` in the same row. A subsequent vol-col SET on the channel restores audibility — exactly mirroring FT2's outVol/realVol gate without diverging the engine. Engine semantics stay IT-pure.
+    [x] FT2/MOD double effects with 00 as arg (500, 600) missing volume column -> easiest solution: fully implement `L xy00` and `K xy00` and map 5xx to L, 6xx to K (xm2taud, mod2taud), Kxy and Lxy verbatim (s3m2taud.py, it2taud.py). This is justified because the volume effects rely on memory when 00 is given, and said memory effect only get recalled when NoteFx is used. TAUD_NOTE_EFFECTS already has detailed implementation notes. Mark those two commands as implemented sorely for tracker compatibility.
+    Also document then implement `Mxx` (set channel volume, not just a note: 0x00 to 0x3F) `Nxy` (channel volume slide: similar to Dxy, but applies to the current channel's volume, not just a note) `Pxy` (channel panning slide. Similar to Dxx: P0y - to the right, Px0 - to the left, PFy - fine pan right, PxF - fine pan left) effects
+    [x] 8 MB sample RAM via 512k banks
+    [x] remove panning mode selection and replace global panning rule to  equal energy, also move the 'ff' flags to bit 0..1
+    [x] low-number voleffs are too quiet (resolved 2026-05-09).
+        Root cause: the converters folded IT `sample.vol` into IGV (byte 171),
+        and the engine multiplied by IGV continuously — so any V-column override
+        on a sample with default vol < 64 was attenuated a second time, while
+        IT/Schism's V column replaces `chan->volume` outright (sample.vol does
+        not feature in the continuous `instrument_volume` factor — see
+        player/csndfile.c:1317 and player/sndmix.c:1171).
+        Fix: split the two concepts apart. Byte 171 (IGV) is now pure
+        `inst.gv * sample.gv` continuous multiplier; new byte 196 ("Default
+        Note Volume") carries `sample.vol` and is consulted by triggerNote
+        when no V column is present. Engine + all four `*2taud` converters
+        updated; legacy `.taud` files (byte 196 == 0) fall back to the
+        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
+        (C) Skaven 1998
+    * Slumberjack — for demonstrating XM-compatible instrument definitions
+        (C) raina 2005
+    * Space Debris — MOD with tons of effects
+        (C) Captain/Image 1991
+    * Changing Waves — for Funk Repeat emulation
+        (C) 4mat/orb 2023
+    * Aboriginal Derivatives — for demonstrating Monotone compatibility.
+        (C) Jakim 2010
+    * SWINGIN1 (rename to Swinging Waste) — for demonstrating Monotone compatibility.
+        (C) Phoenix/Hornet 2015
 
 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
 
 
-Sound Adapter MMIO
+Audio Adapter MMIO
 
 0..1 RW:  Play head #0 position
     PCM mode: number of buffers uploaded and received by the adapter (writing does nothing)
@@ -2051,7 +2471,7 @@ Sound 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.
@@ -2062,11 +2482,17 @@ Sound Adapter MMIO
 44 RW: TAD Decoder Status
     Non-zero value indicates the decoder is busy. Different value may indicate different decoder status.
 45 RW: Select PCM Bin for playhead (writing causes side effects)
+46 RW: Select current sample bank for tracker, exposed at memory space 0..524287
 
 64..2367 RW: MP2 Decoded Samples (unsigned 8-bit stereo)
 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
@@ -2106,9 +2532,15 @@ Play Head Flags
           NOTE: changing from PCM mode to Tracker mode or vice versa will also reset the parameters as described above
     Byte 2
         - PCM Mode: Write non-zero value to start uploading; always 0 when read
-
+        - Tracker Mode: Global mixer flags. Maps directly to Taud effect symbol '1'
+            0b 0000 00ff
+            ff: pitchshift mode (0: linear pitch slides, 1: Amiga period slides, 2: linear-frequency slides, 3: reserved)
+                Tracker command may change the mixer state, but the changes WILL NOT BE REFLECTED BACK.
+                Starting a new song will use whatever written to this register. In other words, changes
+                made by songs will not persist.
+            Panning law is fixed to the equal-energy; there is no runtime selection.
     Byte 3 (Tracker Mode)
-        - BPM (24 to 280. Play Data will change this register)
+        - BPM (25 to 280. Play Data will change this register)
     Byte 4 (Tracker Mode)
         - Tick Rate (Play Data will change this register)
 
@@ -2125,48 +2557,55 @@ Play Head Flags
         Byte 11..20: 0b miV1 miV2, 0b miV3 miV4, 0b miV5 miV6, ... 0b miV19 miV20
         Byte 21..30: 0b hiV1 hiV2, 0b hiV3 hiV4, 0b hiV5 hiV6, ... 0b hiV19 hiV20
     Byte 31..32: instruction
-        1000xxxx yyyyyyyy - Go back 0bxxxxyyyyyyyy patterns
-        1001xxxx yyyyyyyy - Skip forward 0bxxxxyyyyyyyy patterns
-        1111xxxx yyyyyyyy - Go to absolute pattern number 0bxxxxyyyyyyyy
-        00000001 - Halt
+        1000xxxx yyyyyyyy (BAK000) - Go back 0bxxxxyyyyyyyy patterns
+        1001xxxx yyyyyyyy (FWD000) - Skip forward 0bxxxxyyyyyyyy patterns
+        1111xxxx yyyyyyyy (JMP000) - Go to absolute pattern number 0bxxxxyyyyyyyy
+        00000010 00xxxxxx (LEN 00) - Pattern length for this cue (0..63), where 0: 1 row, 63: 64 rows (decoded by AudioAdapter as of 2026-05-05; emitted by xm2taud / it2taud for non-multiple-of-64 source patterns)
+        00000001 00000000 - Halt (HALT  ) - Play the full length of the pattern then stop the playback
+        00000001 00xxxxxx - Fadeout (FADOUT) - Gradually decrease global volume such that at row 0bxxxxxx it reaches zero, then stop the playback
         00000000 - No operation
 
 65536..131071 RW: PCM Sample buffer
 
-Table of 3.5 Minifloat values (CSV)
+Table of 3.5 Minifloat values (CSV).
+Rebiased 2026-05-07 so the smallest non-zero step is 1/256 s and the maximum
+is 15.75 s — every cell is the original LUT value divided by 8. Chosen for
+tracker envelopes: a single song tick (≈ 8.9 ms at BPM 280, ≈ 100 ms at
+BPM 25) now lands within ±17 % of an LUT entry across the whole supported
+BPM range; the previous bias was ±150 % at common BPMs.
      ,000,001,010,011,100,101,110,111,MSB
-00000,0,1,2,4,8,16,32,64
-00001,0.03125,1.03125,2.0625,4.125,8.25,16.5,33,66
-00010,0.0625,1.0625,2.125,4.25,8.5,17,34,68
-00011,0.09375,1.09375,2.1875,4.375,8.75,17.5,35,70
-00100,0.125,1.125,2.25,4.5,9,18,36,72
-00101,0.15625,1.15625,2.3125,4.625,9.25,18.5,37,74
-00110,0.1875,1.1875,2.375,4.75,9.5,19,38,76
-00111,0.21875,1.21875,2.4375,4.875,9.75,19.5,39,78
-01000,0.25,1.25,2.5,5,10,20,40,80
-01001,0.28125,1.28125,2.5625,5.125,10.25,20.5,41,82
-01010,0.3125,1.3125,2.625,5.25,10.5,21,42,84
-01011,0.34375,1.34375,2.6875,5.375,10.75,21.5,43,86
-01100,0.375,1.375,2.75,5.5,11,22,44,88
-01101,0.40625,1.40625,2.8125,5.625,11.25,22.5,45,90
-01110,0.4375,1.4375,2.875,5.75,11.5,23,46,92
-01111,0.46875,1.46875,2.9375,5.875,11.75,23.5,47,94
-10000,0.5,1.5,3,6,12,24,48,96
-10001,0.53125,1.53125,3.0625,6.125,12.25,24.5,49,98
-10010,0.5625,1.5625,3.125,6.25,12.5,25,50,100
-10011,0.59375,1.59375,3.1875,6.375,12.75,25.5,51,102
-10100,0.625,1.625,3.25,6.5,13,26,52,104
-10101,0.65625,1.65625,3.3125,6.625,13.25,26.5,53,106
-10110,0.6875,1.6875,3.375,6.75,13.5,27,54,108
-10111,0.71875,1.71875,3.4375,6.875,13.75,27.5,55,110
-11000,0.75,1.75,3.5,7,14,28,56,112
-11001,0.78125,1.78125,3.5625,7.125,14.25,28.5,57,114
-11010,0.8125,1.8125,3.625,7.25,14.5,29,58,116
-11011,0.84375,1.84375,3.6875,7.375,14.75,29.5,59,118
-11100,0.875,1.875,3.75,7.5,15,30,60,120
-11101,0.90625,1.90625,3.8125,7.625,15.25,30.5,61,122
-11110,0.9375,1.9375,3.875,7.75,15.5,31,62,124
-11111,0.96875,1.96875,3.9375,7.875,15.75,31.5,63,126
+00000,0,0.125,0.25,0.5,1,2,4,8
+00001,0.00390625,0.12890625,0.2578125,0.515625,1.03125,2.0625,4.125,8.25
+00010,0.0078125,0.1328125,0.265625,0.53125,1.0625,2.125,4.25,8.5
+00011,0.01171875,0.13671875,0.2734375,0.546875,1.09375,2.1875,4.375,8.75
+00100,0.015625,0.140625,0.28125,0.5625,1.125,2.25,4.5,9
+00101,0.01953125,0.14453125,0.2890625,0.578125,1.15625,2.3125,4.625,9.25
+00110,0.0234375,0.1484375,0.296875,0.59375,1.1875,2.375,4.75,9.5
+00111,0.02734375,0.15234375,0.3046875,0.609375,1.21875,2.4375,4.875,9.75
+01000,0.03125,0.15625,0.3125,0.625,1.25,2.5,5,10
+01001,0.03515625,0.16015625,0.3203125,0.640625,1.28125,2.5625,5.125,10.25
+01010,0.0390625,0.1640625,0.328125,0.65625,1.3125,2.625,5.25,10.5
+01011,0.04296875,0.16796875,0.3359375,0.671875,1.34375,2.6875,5.375,10.75
+01100,0.046875,0.171875,0.34375,0.6875,1.375,2.75,5.5,11
+01101,0.05078125,0.17578125,0.3515625,0.703125,1.40625,2.8125,5.625,11.25
+01110,0.0546875,0.1796875,0.359375,0.71875,1.4375,2.875,5.75,11.5
+01111,0.05859375,0.18359375,0.3671875,0.734375,1.46875,2.9375,5.875,11.75
+10000,0.0625,0.1875,0.375,0.75,1.5,3,6,12
+10001,0.06640625,0.19140625,0.3828125,0.765625,1.53125,3.0625,6.125,12.25
+10010,0.0703125,0.1953125,0.390625,0.78125,1.5625,3.125,6.25,12.5
+10011,0.07421875,0.19921875,0.3984375,0.796875,1.59375,3.1875,6.375,12.75
+10100,0.078125,0.203125,0.40625,0.8125,1.625,3.25,6.5,13
+10101,0.08203125,0.20703125,0.4140625,0.828125,1.65625,3.3125,6.625,13.25
+10110,0.0859375,0.2109375,0.421875,0.84375,1.6875,3.375,6.75,13.5
+10111,0.08984375,0.21484375,0.4296875,0.859375,1.71875,3.4375,6.875,13.75
+11000,0.09375,0.21875,0.4375,0.875,1.75,3.5,7,14
+11001,0.09765625,0.22265625,0.4453125,0.890625,1.78125,3.5625,7.125,14.25
+11010,0.1015625,0.2265625,0.453125,0.90625,1.8125,3.625,7.25,14.5
+11011,0.10546875,0.23046875,0.4609375,0.921875,1.84375,3.6875,7.375,14.75
+11100,0.109375,0.234375,0.46875,0.9375,1.875,3.75,7.5,15
+11101,0.11328125,0.23828125,0.4765625,0.953125,1.90625,3.8125,7.625,15.25
+11110,0.1171875,0.2421875,0.484375,0.96875,1.9375,3.875,7.75,15.5
+11111,0.12109375,0.24609375,0.4921875,0.984375,1.96875,3.9375,7.875,15.75
 LSB
 
 ## Tracker Note Effects
@@ -2178,82 +2617,202 @@ Tracker Note Effects has been moved to `TAUD_NOTE_EFFECTS.md`
 **Taud serialisation format**
 Created by CuriousTorvald on 2026-04-19
 
-This is a file format for Taud tracker data.
+This is a file format for Taud tracker data. Taud can be extended with Microtone (taut.js) project data in backward-and-forward-compatible manner.
+
+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]
 [SAMPLE+INSTRUMENT BIN IMAGE (GZip or Zstd compressed. Read 4-byte magic to determine)]
 [SONG TABLE]
-[PATTERN BIN for SONG 0]
-[CUE SHEET for SONG 0]
-[PATTERN BIN for SONG 1]
-[CUE SHEET for SONG 1]
-[PATTERN BIN for SONG 2]
-[CUE SHEET for SONG 2]
+[PATTERN BIN for SONG 0 (GZip or Zstd compressed)]
+[CUE SHEET for SONG 0 (GZip or Zstd compressed)]
+[PATTERN BIN for SONG 1 (GZip or Zstd compressed)]
+[CUE SHEET for SONG 1 (GZip or Zstd compressed)]
+[PATTERN BIN for SONG 2 (GZip or Zstd compressed)]
+[CUE SHEET for SONG 2 (GZip or Zstd compressed)]
 ...
+[PROJECT DATA] (optional)
+    [DATA BLOCKS WITH FOURCC HEADER (see Project Data section)]
 
 ## Header
     Byte[8] Magic
     Uint8   Format version (always 1)
     Uint8   Number of songs in SONG TABLE
     Uint32  Compressed size of SAMPLE+INST section (used to calculate offset to SONG TABLE)
-    Uint16  Reserved for future versions
-    Byte[16]Tracker/Converter signature
+    Uint32  Offset to Project Data. Zero if Project Data is nonexistent
+    Byte[14]Tracker/Converter signature
 
-## SONG TABLE
-Rows of 16 bytes:
+## Sample and Instrument bin image
+    8256 kB when decompressed. First 8 MB holds samples.
+
+## Song Table
+    * Rows of 32 bytes:
     Uint32  Song offset
     Uint8   Number of voices
     Uint16  Number of patterns (0 is invalid. pattern bin length = numPats * 8 bytes)
-    Uint8   Initial BPM (bias of -24. 0x00=24, 0xFF=279)
-    Uint8   Initial Tickrate(0 is invalid)
-    Byte[7] Reserved for future versions
+    Uint8   Initial BPM (bias of -25. 0x00=25, 0xFF=280)
+    Uint8   Initial Tickrate (0 is invalid)
+    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 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
 
-Taud device can queue up to 2 "playdata" in its buffer, which can be interpreted as a song.
+    Taud device can queue up to 2 "playdata" in its buffer, which can be interpreted as a song.
 
---------------------------------------------------------------------------------
+    * Known standard tunings:
+    A4 @ 440 Hz. ISO standard
+    A4 @ 435 Hz. Former French standard (year 1859)
+    A4 @ 452 Hz. Old Philharmonic pitch (19th century Britain)
+    C4 @ 256 Hz. Power of two
+    C4 @ 262 Hz. Modern Chinese a-ak tuning convention
+    C4 @ 311 Hz. Korean hyang-ak tuning standard (ROK National Gugak Center)
 
-**Taud Project Format** is an extension to Taud format
-Created by CuriousTorvald on 2026-04-22
+    For your reference, tracker default tuning at A4 is 439.526 Hz (8363*2^(3/4) / 32)
 
-# File Structure
-\x1F T S V M a u d
-[HEADER] (modified)
-[SAMPLE+INSTRUMENT BIN IMAGE (GZip or Zstd compressed. Read 4-byte magic to determine)]
-[SONG TABLE]
-[PATTERN BIN for SONG 0]
-[CUE SHEET for SONG 0]
-[PATTERN BIN for SONG 1]
-[CUE SHEET for SONG 1]
-[PATTERN BIN for SONG 2]
-[CUE SHEET for SONG 2]
-...
-[PROJECT DATA] (new!)
-
-## Header
-    Byte[8] Magic
-    Uint8   Format version (always 129)
-    Uint8   Number of songs in SONG TABLE
-    Uint32  Compressed size of SAMPLE+INST section (used to calculate offset to SONG TABLE)
-    Uint16  Offset to Project Data (low twobyte)
-    Byte[14]Tracker/Converter signature
-    Uint16  Offset to Project Data (high twobyte)
+## Pattern Bin and Cue Sheet
+    RAM image of Pattern Bin/Cue Sheet
 
 ## Project Data
+
+Project Data is just a concatenation of blocks identified by their FourCC.
+
     Byte[8] Magic (\x1E T a u d P r J)
-    Uint16  Pitch table preset
-    Uint16  Current Tuning base note (0-4095), assuming octave 3
-    Uint16  Frequency at the base note (Float16)
+    Byte[8] RESERVED
     * Repetition of
     Byte[4] Title of the section (fourcc)
-    Uint16  Section length
+    Uint32  Section length
     Byte[*] Section payload
 
 ### Predefined sections
 
-* NOTA. Custom notation definition. Strings separated by comma
+prefixes:
 
+- P: Project
+- I: Instrument
+- p: Pattern
+- S: Sample
+- s: Song
+
+* 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
+
+* pNam. Pattern name table. Strings separated by 0x1E
+
+* SNam. Sample name table. Strings separated by 0x1E
+
+* sMet. Song metadata table
+    * Repetition of:
+    Uint8  Song index
+    Uint32 Size of this table following this field
+    Uint16 Notation used for this song (takes notation index)
+        0: raw numbers
+        10*n: TET-number times 10 (12-TET = 120)
+        * Following systems have alternative notation conventions:
+        531: 53-TET Pythagorean Notation
+        * Following list defines ethnic notations in 12-tone scale
+        10121: Pythagorean Diminished Fifth
+        10122: Pythagorean Augmented Fourth
+        10123: Shi'er lü (East Asian traditional tuning)
+    Uint8  Primary beat division (default: 4 rows)
+    Uint8  Secondary beat division (default: 16 rows)
+
+    Byte[*]     Song name, null terminated. Encoding: UTF-8
+    Byte[*]     Song composer, null terminated. Encoding: UTF-8
+    Byte[*]     Song copyright string, null terminated. Encoding: UTF-8
+
+* nota. Custom notation definition (version 'a')
+    * Repetition of:
+    Uint8   Notation index (starting from zero) used by songs
+    Uint32  Size of this notation following this field
+    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
+
+    Note: custom notations will use internal index 65535 down to 65520 (index 0 = 65535, index 15 = 65520)
+
+    Note Tuning:
+        1. "Base Note at C4" will be derived using "Current Tuning Base Note" and "Frequency at the Base Note" from the song table. If the values are A4,440Hz, it will be converted to C4,261.6255653Hz
+        2. Frequency at C5 will be (Base Note at C4) × (Interval Size)
+        3. 4096 notes will be equidistance-distributed between (Frequency at C3) and (Frequency at C4), with logarithmic pitch progression; this builds the frequency-offset table
+        4. Frequency-Offset Table from the previous step will be applied against the "Base Note at C3" to construct the notes within the notation. Value at index zero of the Frequency Table must be 0
+        5. The progress will continue outside the "root interval" (C3..C4) to build a complete note-to-frequency table
+
+        Note: if your sample is pre-tuned for your system, keep the project setting as the defaults. If you are not working with the conventional octave system, you still need to specify the Interval Size
+
+    * Suggested notation serialisation format (for notation editor, etc.)
+    Byte[8] Magic (\x1E T a u d n o t)
+    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.
 
 --------------------------------------------------------------------------------
 
@@ -2316,7 +2875,7 @@ The halt instruction (byte value 0x01 at cue offset 30) is placed on the last ac
 
 ## Tempo mapping
 
-S3M BPM is stored as a raw decimal value. Taud's initial BPM byte uses a bias of -24 (byte 0x00 = 24 BPM, 0xFF = 279 BPM). Conversion: taud_byte = bpm - 24. The converter also scans row 0 of the first pattern in the order list for A (set speed) and T (set tempo) effects and uses those values in preference to the S3M header defaults.
+S3M BPM is stored as a raw decimal value. Taud's initial BPM byte uses a bias of -25 (byte 0x00 = 25 BPM, 0xFF = 280 BPM). Conversion: taud_byte = bpm - 25. The converter also scans row 0 of the first pattern in the order list for A (set speed) and T (set tempo) effects and uses those values in preference to the S3M header defaults.
 
 ## Global volume
 

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
  *
@@ -75,7 +77,7 @@ class AudioJSR223Delegate(private val vm: VM) {
 
     fun startSampleUpload(playhead: Int) { getPlayhead(playhead)?.pcmUpload = true }
 
-    fun setBPM(playhead: Int, bpm: Int) { getPlayhead(playhead)?.bpm = (bpm - 24).and(255) + 24 }
+    fun setBPM(playhead: Int, bpm: Int) { getPlayhead(playhead)?.bpm = (bpm - 25).and(255) + 25 }
     fun getBPM(playhead: Int) = getPlayhead(playhead)?.bpm
 
     fun setTickRate(playhead: Int, rate: Int) { getPlayhead(playhead)?.tickRate = rate and 255 }
@@ -89,13 +91,238 @@ class AudioJSR223Delegate(private val vm: VM) {
     }
     fun getCuePosition(playhead: Int) = getPlayhead(playhead)?.position
 
-    /** Upload 64 bytes defining instrument `slot` (0-255). */
+    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))?.fader = if (muted) 255 else 0
+    }
+    fun getVoiceMute(playhead: Int, voice: Int): Boolean =
+        (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) {
+        getPlayhead(playhead)?.trackerState?.let { ts ->
+            ts.rowIndex = row.coerceIn(0, 63)
+            ts.tickInRow = 0
+            ts.samplesIntoTick = 0.0
+            ts.firstRow = true
+            ts.pendingOrderJump = -1
+            ts.pendingRowJump = -1
+            ts.voices.forEach { it.active = false }
+        }
+    }
+
+    /** Upload up to 192 bytes defining instrument `slot` (0-255). */
     fun uploadInstrument(slot: Int, bytes: IntArray) {
         getFirstSnd()?.instruments?.get(slot and 0xFF)?.let { inst ->
-            for (i in 0 until minOf(64, bytes.size)) inst.setByte(i, bytes[i] and 0xFF)
+            for (i in 0 until minOf(192, bytes.size)) inst.setByte(i, bytes[i] and 0xFF)
         }
     }
 
+    /** 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 ->
@@ -110,6 +337,23 @@ class AudioJSR223Delegate(private val vm: VM) {
         }
     }
 
+    fun setTrackerMixerFlags(playhead: Int, flags: Int) {
+        getFirstSnd()?.playheads?.get(playhead)?.let { ph ->
+            ph.initialGlobalFlags = flags
+            ph.updateTrackerGlobalBehaviour(flags)
+        }
+    }
+
+    fun getTrackerMixerFlags(playhead: Int): Int? {
+        return getFirstSnd()?.playheads?.get(playhead)?.initialGlobalFlags
+    }
+
+    fun setSongGlobalVolume(playhead: Int, volume: Int) { getPlayhead(playhead)?.globalVolume = volume and 255 }
+    fun getSongGlobalVolume(playhead: Int) = getPlayhead(playhead)?.globalVolume
+
+    fun setSongMixingVolume(playhead: Int, volume: Int) { getPlayhead(playhead)?.mixingVolume = volume and 255 }
+    fun getSongMixingVolume(playhead: Int) = getPlayhead(playhead)?.mixingVolume
+
     fun putPcmDataByPtr(playhead: Int, ptr: Int, length: Int, destOffset: Int) {
         getFirstSnd()?.let {
             val vkMult = if (ptr >= 0) 1 else -1
@@ -129,6 +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()
     }
@@ -142,6 +393,61 @@ class AudioJSR223Delegate(private val vm: VM) {
 
     fun getBaseAddr(): Int? = getFirstSnd()?.let { return it.vm.findPeriSlotNum(it)?.times(-131072)?.minus(1) }
     fun getMemAddr(): Int? = getFirstSnd()?.let { return it.vm.findPeriSlotNum(it)?.times(-1048576)?.minus(1) }
+
+    /** Switch the sample-bin window (peripheral memory 0..524287) to bank `bank` (0..15).
+     *  The 8 MB sample pool is organised as 16 × 512 K banks; only the selected bank
+     *  is visible through the window. (terranmon.txt:1985-1997, MMIO 46.) */
+    fun setSampleBank(bank: Int) { getFirstSnd()?.mmio_write(46L, bank.toByte()) }
+    fun getSampleBank(): Int? = getFirstSnd()?.sampleBank
+
+    /** Decompress a Taud sample+instrument blob (gzip or zstd) directly into the
+     *  audio adapter's 8 MB sample pool and 64 K instrument bin, bypassing the user
+     *  memory staging buffer. The decompressed payload must be exactly
+     *  `SAMPLE_BIN_TOTAL + 65536` bytes (8 MB samples followed by 64 K instruments).
+     *
+     *  Needed because user space is capped at 8 MB and cannot hold the full 8256 kB
+     *  decompressed image as a contiguous buffer. */
+    fun uploadSampleInstBlob(srcPtr: Int, srcLen: Int): Int {
+        val snd = getFirstSnd() ?: return 0
+        val inbytes = ByteArray(srcLen) { vm.peek(srcPtr.toLong() + it)!! }
+        val bytes = CompressorDelegate.decomp(inbytes)
+        val sampleSize = AudioAdapter.SAMPLE_BIN_TOTAL.toInt()
+        val instSize = 65536
+        if (bytes.size < sampleSize + instSize) return 0
+        UnsafeHelper.memcpyRaw(
+            bytes, UnsafeHelper.getArrayOffset(bytes),
+            null, snd.sampleBin.ptr,
+            sampleSize.toLong()
+        )
+        for (i in 0 until instSize) {
+            snd.instruments[i / 256].setByte(i % 256, bytes[sampleSize + i].toInt() and 0xFF)
+        }
+        return bytes.size
+    }
+
+    /** Compress the audio adapter's full 8 MB sample pool + 64 K instrument bin
+     *  (8256 kB total) and write the resulting gzip/zstd blob to user-memory `dstPtr`.
+     *  Returns the compressed size. The caller must ensure `dstMaxLen` is large
+     *  enough; for incompressible noise the worst case is ~8.3 MB which exceeds
+     *  user space — but realistic sample data compresses easily. */
+    fun captureSampleInstBlob(dstPtr: Int, dstMaxLen: Int): Int {
+        val snd = getFirstSnd() ?: return 0
+        val sampleSize = AudioAdapter.SAMPLE_BIN_TOTAL.toInt()
+        val instSize = 65536
+        val raw = ByteArray(sampleSize + instSize)
+        UnsafeHelper.memcpyRaw(
+            null, snd.sampleBin.ptr,
+            raw, UnsafeHelper.getArrayOffset(raw),
+            sampleSize.toLong()
+        )
+        for (i in 0 until instSize) {
+            raw[sampleSize + i] = snd.instruments[i / 256].getByte(i % 256)
+        }
+        val compressed = CompressorDelegate.comp(raw)
+        val n = minOf(compressed.size, dstMaxLen)
+        for (i in 0 until n) vm.poke((dstPtr + i).toLong(), compressed[i])
+        return compressed.size
+    }
     fun mp2Init() = getFirstSnd()?.mmio_write(40L, 16)
     fun mp2Decode() = getFirstSnd()?.mmio_write(40L, 1)
     fun mp2InitThenDecode() = getFirstSnd()?.mmio_write(40L, 17)
@@ -182,6 +488,7 @@ class AudioJSR223Delegate(private val vm: VM) {
 
 
 
+    // while the following code does work, it was decided that MP3 is "too new" for tsvm and thus removed.
     /*
     js-mp3
     https://github.com/soundbus-technologies/js-mp3

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
      */
@@ -5433,6 +5562,18 @@ class GraphicsJSR223Delegate(private val vm: VM) {
 
     private val TAV_QLUT = intArrayOf(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96,98,100,102,104,106,108,110,112,114,116,118,120,122,124,126,128,132,136,140,144,148,152,156,160,164,168,172,176,180,184,188,192,196,200,204,208,212,216,220,224,228,232,236,240,244,248,252,256,264,272,280,288,296,304,312,320,328,336,344,352,360,368,376,384,392,400,408,416,424,432,440,448,456,464,472,480,488,496,504,512,528,544,560,576,592,608,624,640,656,672,688,704,720,736,752,768,784,800,816,832,848,864,880,896,912,928,944,960,976,992,1008,1024,1056,1088,1120,1152,1184,1216,1248,1280,1312,1344,1376,1408,1440,1472,1504,1536,1568,1600,1632,1664,1696,1728,1760,1792,1824,1856,1888,1920,1952,1984,2016,2048,2112,2176,2240,2304,2368,2432,2496,2560,2624,2688,2752,2816,2880,2944,3008,3072,3136,3200,3264,3328,3392,3456,3520,3584,3648,3712,3776,3840,3904,3968,4032,4096)
 
+    // Zstd magic = 0x28 0xB5 0x2F 0xFD (little-endian frame magic).
+    // Newer TAV files default to no Zstd (Video Flags bit 4); detecting the magic
+    // lets the decoder accept both compressed and raw payloads transparently.
+    private fun tavDecompressIfZstd(data: ByteArray): ByteArray {
+        if (data.size >= 4 &&
+            data[0] == 0x28.toByte() && data[1] == 0xB5.toByte() &&
+            data[2] == 0x2F.toByte() && data[3] == 0xFD.toByte()) {
+            return ZstdInputStream(ByteArrayInputStream(data)).use { it.readBytes() }
+        }
+        return data
+    }
+
     // New tavDecode function that accepts compressed data and decompresses internally
     fun tavDecodeCompressed(compressedDataPtr: Long, compressedSize: Int, currentRGBAddr: Long, prevRGBAddr: Long,
                             width: Int, height: Int, qIndex: Int, qYGlobal: Int, qCoGlobal: Int, qCgGlobal: Int, channelLayout: Int,
@@ -5445,12 +5586,9 @@ class GraphicsJSR223Delegate(private val vm: VM) {
         }
 
         return try {
-            // Decompress using Zstd
-            val bais = ByteArrayInputStream(compressedData)
-            val zis = ZstdInputStream(bais)
-            val decompressedData = zis.readBytes()
-            zis.close()
-            bais.close()
+            // Decompress with Zstd if the payload starts with the Zstd frame magic;
+            // otherwise pass through (TAV files written without --zstd-level).
+            val decompressedData = tavDecompressIfZstd(compressedData)
 
             // Allocate buffer for decompressed data
             val decompressedBuffer = vm.malloc(decompressedData.size)
@@ -6725,9 +6863,9 @@ class GraphicsJSR223Delegate(private val vm: VM) {
         )
 
         val decompressedData = try {
-            ZstdInputStream(java.io.ByteArrayInputStream(compressedData)).use { zstd ->
-                zstd.readBytes()
-            }
+            // Decompress with Zstd if the payload starts with the Zstd frame magic;
+            // otherwise pass through (TAV files written without --zstd-level).
+            tavDecompressIfZstd(compressedData)
         } catch (e: Exception) {
             println("ERROR: Zstd decompression failed: ${e.message}")
             return arrayOf(0, dbgOut)

tsvm_core/src/net/torvald/tsvm/JS_INIT.js

@@ -479,21 +479,21 @@ con.getmaxyx = function() {
 con.getyx = function() {
     return graphics.getCursorYX();
 };
-con.curs_up = function() {
+con.curs_up = function(n = 1) {
     let [y,x] = con.getyx();
-    con.move(y-1,x);
+    con.move(y-n,x);
 };
-con.curs_down = function() {
+con.curs_down = function(n = 1) {
     let [y,x] = con.getyx();
-    con.move(y+1,x);
+    con.move(y+n,x);
 };
-con.curs_left = function() {
+con.curs_left = function(n = 1) {
     let [y,x] = con.getyx();
-    con.move(y,x-1);
+    con.move(y,x-n);
 };
-con.curs_right = function() {
+con.curs_right = function(n = 1) {
     let [y,x] = con.getyx();
-    con.move(y,x+1);
+    con.move(y,x+n);
 };
 con.hitterminate = function() { // ^C
     sys.poke(-40, 1);

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

@@ -1,7 +1,15 @@
 package net.torvald.tsvm
 
 /**
- * Created by minjaesong on 2022-12-30.
+ * 3.5 unsigned minifloat (3-bit exponent + 5-bit mantissa), scaled so the
+ * smallest non-zero step is 1/256 s ≈ 3.91 ms and the maximum representable
+ * value is 15.75 s. Used for Taud envelope point offsets — the resolution at
+ * the low end is fine enough to resolve individual tracker ticks at every
+ * supported BPM (worst case ±17 % at BPM 250+, vs. ±150 % under the original
+ * 1/32-step bias).
+ *
+ * Created by minjaesong on 2022-12-30. Rebiased for tracker tick resolution
+ * on 2026-05-07 (entire LUT divided by 8).
  */
 @JvmInline
 value class ThreeFiveMiniUfloat(val index: Int = 0) {
@@ -11,7 +19,7 @@ value class ThreeFiveMiniUfloat(val index: Int = 0) {
     }
 
     companion object {
-        val LUT = floatArrayOf(0f,0.03125f,0.0625f,0.09375f,0.125f,0.15625f,0.1875f,0.21875f,0.25f,0.28125f,0.3125f,0.34375f,0.375f,0.40625f,0.4375f,0.46875f,0.5f,0.53125f,0.5625f,0.59375f,0.625f,0.65625f,0.6875f,0.71875f,0.75f,0.78125f,0.8125f,0.84375f,0.875f,0.90625f,0.9375f,0.96875f,1f,1.03125f,1.0625f,1.09375f,1.125f,1.15625f,1.1875f,1.21875f,1.25f,1.28125f,1.3125f,1.34375f,1.375f,1.40625f,1.4375f,1.46875f,1.5f,1.53125f,1.5625f,1.59375f,1.625f,1.65625f,1.6875f,1.71875f,1.75f,1.78125f,1.8125f,1.84375f,1.875f,1.90625f,1.9375f,1.96875f,2f,2.0625f,2.125f,2.1875f,2.25f,2.3125f,2.375f,2.4375f,2.5f,2.5625f,2.625f,2.6875f,2.75f,2.8125f,2.875f,2.9375f,3f,3.0625f,3.125f,3.1875f,3.25f,3.3125f,3.375f,3.4375f,3.5f,3.5625f,3.625f,3.6875f,3.75f,3.8125f,3.875f,3.9375f,4f,4.125f,4.25f,4.375f,4.5f,4.625f,4.75f,4.875f,5f,5.125f,5.25f,5.375f,5.5f,5.625f,5.75f,5.875f,6f,6.125f,6.25f,6.375f,6.5f,6.625f,6.75f,6.875f,7f,7.125f,7.25f,7.375f,7.5f,7.625f,7.75f,7.875f,8f,8.25f,8.5f,8.75f,9f,9.25f,9.5f,9.75f,10f,10.25f,10.5f,10.75f,11f,11.25f,11.5f,11.75f,12f,12.25f,12.5f,12.75f,13f,13.25f,13.5f,13.75f,14f,14.25f,14.5f,14.75f,15f,15.25f,15.5f,15.75f,16f,16.5f,17f,17.5f,18f,18.5f,19f,19.5f,20f,20.5f,21f,21.5f,22f,22.5f,23f,23.5f,24f,24.5f,25f,25.5f,26f,26.5f,27f,27.5f,28f,28.5f,29f,29.5f,30f,30.5f,31f,31.5f,32f,33f,34f,35f,36f,37f,38f,39f,40f,41f,42f,43f,44f,45f,46f,47f,48f,49f,50f,51f,52f,53f,54f,55f,56f,57f,58f,59f,60f,61f,62f,63f,64f,66f,68f,70f,72f,74f,76f,78f,80f,82f,84f,86f,88f,90f,92f,94f,96f,98f,100f,102f,104f,106f,108f,110f,112f,114f,116f,118f,120f,122f,124f,126f)
+        val LUT = floatArrayOf(0f,0.00390625f,0.0078125f,0.01171875f,0.015625f,0.01953125f,0.0234375f,0.02734375f,0.03125f,0.03515625f,0.0390625f,0.04296875f,0.046875f,0.05078125f,0.0546875f,0.05859375f,0.0625f,0.06640625f,0.0703125f,0.07421875f,0.078125f,0.08203125f,0.0859375f,0.08984375f,0.09375f,0.09765625f,0.1015625f,0.10546875f,0.109375f,0.11328125f,0.1171875f,0.12109375f,0.125f,0.12890625f,0.1328125f,0.13671875f,0.140625f,0.14453125f,0.1484375f,0.15234375f,0.15625f,0.16015625f,0.1640625f,0.16796875f,0.171875f,0.17578125f,0.1796875f,0.18359375f,0.1875f,0.19140625f,0.1953125f,0.19921875f,0.203125f,0.20703125f,0.2109375f,0.21484375f,0.21875f,0.22265625f,0.2265625f,0.23046875f,0.234375f,0.23828125f,0.2421875f,0.24609375f,0.25f,0.2578125f,0.265625f,0.2734375f,0.28125f,0.2890625f,0.296875f,0.3046875f,0.3125f,0.3203125f,0.328125f,0.3359375f,0.34375f,0.3515625f,0.359375f,0.3671875f,0.375f,0.3828125f,0.390625f,0.3984375f,0.40625f,0.4140625f,0.421875f,0.4296875f,0.4375f,0.4453125f,0.453125f,0.4609375f,0.46875f,0.4765625f,0.484375f,0.4921875f,0.5f,0.515625f,0.53125f,0.546875f,0.5625f,0.578125f,0.59375f,0.609375f,0.625f,0.640625f,0.65625f,0.671875f,0.6875f,0.703125f,0.71875f,0.734375f,0.75f,0.765625f,0.78125f,0.796875f,0.8125f,0.828125f,0.84375f,0.859375f,0.875f,0.890625f,0.90625f,0.921875f,0.9375f,0.953125f,0.96875f,0.984375f,1f,1.03125f,1.0625f,1.09375f,1.125f,1.15625f,1.1875f,1.21875f,1.25f,1.28125f,1.3125f,1.34375f,1.375f,1.40625f,1.4375f,1.46875f,1.5f,1.53125f,1.5625f,1.59375f,1.625f,1.65625f,1.6875f,1.71875f,1.75f,1.78125f,1.8125f,1.84375f,1.875f,1.90625f,1.9375f,1.96875f,2f,2.0625f,2.125f,2.1875f,2.25f,2.3125f,2.375f,2.4375f,2.5f,2.5625f,2.625f,2.6875f,2.75f,2.8125f,2.875f,2.9375f,3f,3.0625f,3.125f,3.1875f,3.25f,3.3125f,3.375f,3.4375f,3.5f,3.5625f,3.625f,3.6875f,3.75f,3.8125f,3.875f,3.9375f,4f,4.125f,4.25f,4.375f,4.5f,4.625f,4.75f,4.875f,5f,5.125f,5.25f,5.375f,5.5f,5.625f,5.75f,5.875f,6f,6.125f,6.25f,6.375f,6.5f,6.625f,6.75f,6.875f,7f,7.125f,7.25f,7.375f,7.5f,7.625f,7.75f,7.875f,8f,8.25f,8.5f,8.75f,9f,9.25f,9.5f,9.75f,10f,10.25f,10.5f,10.75f,11f,11.25f,11.5f,11.75f,12f,12.25f,12.5f,12.75f,13f,13.25f,13.5f,13.75f,14f,14.25f,14.5f,14.75f,15f,15.25f,15.5f,15.75f)
 
         private fun fromFloatToIndex(fval: Float): Int {
             val (llim, hlim) = binarySearchInterval(fval, LUT)

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

@@ -29,8 +29,10 @@ internal object UnsafeHelper {
         return UnsafePtr(ptr, size, caller)
     }
 
-    fun memcpy(src: UnsafePtr, fromIndex: Long, dest: UnsafePtr, toIndex: Long, copyLength: Long) =
+    fun memcpy(src: UnsafePtr, fromIndex: Long, dest: UnsafePtr, toIndex: Long, copyLength: Long) {
+        if (src.destroyed || dest.destroyed) return
         unsafe.copyMemory(src.ptr + fromIndex, dest.ptr + toIndex, copyLength)
+    }
     fun memcpy(srcAddress: Long, destAddress: Long, copyLength: Long) =
         unsafe.copyMemory(srcAddress, destAddress, copyLength)
     fun memcpyRaw(srcObj: Any?, srcPos: Long, destObj: Any?, destPos: Long, len: Long) =
@@ -84,81 +86,96 @@ internal class UnsafePtr(pointer: Long, allocSize: Long, private val caller: Any
         }
     }
 
-    private inline fun checkNullPtr(index: Long) { // ignore what IDEA says and do inline this
-        //// commenting out because of the suspected (or minor?) performance impact.
-        //// You may break the glass and use this tool when some fucking incomprehensible bugs ("vittujen vitun bugit")
-        //// appear (e.g. getting garbage values when it fucking shouldn't)
-
-//        if (destroyed) { throw DanglingPointerException("The pointer is already destroyed ($this)") }
-//        if (index !in 0 until size) throw AddressOverflowException("Index: $index; alloc size: $size; pointer: ${this}\n${Thread.currentThread().stackTrace.joinToString("\n", limit=10) { "    $it" }}")
+    /**
+     * Returns true when the operation should proceed; false when the pointer is destroyed
+     * (so the caller short-circuits to a safe no-op / zero return).
+     *
+     * Why no exception: a JS worker thread that survives killVMenv (because it wasn't
+     * tracked in vm.contexts, e.g. raw java.lang.Thread spawned by JS code) will keep
+     * poking peripheral memory for one or more iterations after dispose(). Letting it
+     * actually call unsafe.putByte on freed memory corrupts the malloc heap and crashes
+     * the JVM with `free_list_checksum_botch`. Returning quietly turns the race into a
+     * harmless no-op until the thread drains.
+     */
+    private inline fun aliveAt(index: Long): Boolean {
+        if (destroyed) return false
+        if (index < 0 || index >= size) return false
+        return true
     }
 
     operator fun get(index: Long): Byte {
-        checkNullPtr(index)
+        if (!aliveAt(index)) return 0
         return UnsafeHelper.unsafe.getByte(ptr + index)
     }
 
     operator fun set(index: Long, value: Byte) {
-        checkNullPtr(index)
+        if (!aliveAt(index)) return
         UnsafeHelper.unsafe.putByte(ptr + index, value)
     }
 
 
     fun getFloatFree(index: Long): Float {
-        checkNullPtr(index)
+        if (!aliveAt(index + 3)) return 0f
         return UnsafeHelper.unsafe.getFloat(ptr + index)
     }
     fun getFloat(unit: Long): Float {
-        checkNullPtr(unit * 4L)
-        return UnsafeHelper.unsafe.getFloat(ptr + (unit * 4L))
+        val idx = unit * 4L
+        if (!aliveAt(idx + 3)) return 0f
+        return UnsafeHelper.unsafe.getFloat(ptr + idx)
     }
 
     fun getIntFree(index: Long): Int {
-        checkNullPtr(index)
+        if (!aliveAt(index + 3)) return 0
         return UnsafeHelper.unsafe.getInt(ptr + index)
     }
     fun getInt(unit: Long): Int {
-        checkNullPtr(unit * 4L)
-        return UnsafeHelper.unsafe.getInt(ptr + (unit * 4L))
+        val idx = unit * 4L
+        if (!aliveAt(idx + 3)) return 0
+        return UnsafeHelper.unsafe.getInt(ptr + idx)
     }
 
     fun getShortFree(index: Long): Short {
-        checkNullPtr(index)
+        if (!aliveAt(index + 1)) return 0
         return UnsafeHelper.unsafe.getShort(ptr + index)
     }
     fun getShort(unit: Long): Short {
-        checkNullPtr(unit * 2L)
-        return UnsafeHelper.unsafe.getShort(ptr + (unit * 2L))
+        val idx = unit * 2L
+        if (!aliveAt(idx + 1)) return 0
+        return UnsafeHelper.unsafe.getShort(ptr + idx)
     }
 
     fun setFloatFree(index: Long, value: Float) {
-        checkNullPtr(index)
+        if (!aliveAt(index + 3)) return
         UnsafeHelper.unsafe.putFloat(ptr + index, value)
     }
     fun setFloat(unit: Long, value: Float) {
-        checkNullPtr(unit * 4L)
-        UnsafeHelper.unsafe.putFloat(ptr + (unit * 4L), value)
+        val idx = unit * 4L
+        if (!aliveAt(idx + 3)) return
+        UnsafeHelper.unsafe.putFloat(ptr + idx, value)
     }
 
     fun setIntFree(index: Long, value: Int) {
-        checkNullPtr(index)
+        if (!aliveAt(index + 3)) return
         UnsafeHelper.unsafe.putInt(ptr + index, value)
     }
     fun setInt(unit: Long, value: Int) {
-        checkNullPtr(unit * 4L)
-        UnsafeHelper.unsafe.putInt(ptr + (unit * 4L), value)
+        val idx = unit * 4L
+        if (!aliveAt(idx + 3)) return
+        UnsafeHelper.unsafe.putInt(ptr + idx, value)
     }
 
     fun setShortFree(index: Long, value: Short) {
-        checkNullPtr(index)
+        if (!aliveAt(index + 1)) return
         UnsafeHelper.unsafe.putShort(ptr + index, value)
     }
     fun setShortUnit(unit: Long, value: Short) {
-        checkNullPtr(unit * 2L)
-        UnsafeHelper.unsafe.putShort(ptr + (unit * 2L), value)
+        val idx = unit * 2L
+        if (!aliveAt(idx + 1)) return
+        UnsafeHelper.unsafe.putShort(ptr + idx, value)
     }
 
     fun fillWith(byte: Byte) {
+        if (destroyed) return
         UnsafeHelper.unsafe.setMemory(ptr, size, byte)
     }
 

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

@@ -12,6 +12,7 @@ import java.io.OutputStream
 import java.nio.charset.Charset
 import java.util.*
 import java.util.concurrent.atomic.AtomicBoolean
+import kotlin.math.absoluteValue
 import kotlin.math.ceil
 
 
@@ -325,8 +326,37 @@ class VM(
     }
 
     fun killAllContexts() {
-        contexts.forEach { it.interrupt() }
+        // Snapshot first: interrupt() can race with the worker thread mutating `contexts`
+        // (see Parallel.kill / attachProgram) and we want to wait on every one of them.
+        val snapshot = contexts.toList()
+        snapshot.forEach { it.interrupt() }
+        snapshot.forEach {
+            try { it.join(500L) } catch (_: InterruptedException) { Thread.currentThread().interrupt() }
+        }
         contexts.clear()
+
+        // Some JS code (e.g. TVDOS) spawns workers that aren't routed through Parallel.attachProgram,
+        // so they never land in `contexts`. We can still find them by walking the JVM thread set and
+        // matching the per-VM suffix that VMRunnerFactory uses for thread names ("…!<vmId>").
+        val suffix = "!${id.text}"
+        val all = arrayOfNulls<Thread>(Thread.activeCount() * 2)
+        val n = Thread.enumerate(all)
+        for (i in 0 until n) {
+            val t = all[i] ?: continue
+            if (t === Thread.currentThread()) continue
+            val name = t.name
+            if (name.endsWith(suffix) || name == "VmRunner:${id.text}") {
+                t.interrupt()
+            }
+        }
+        for (i in 0 until n) {
+            val t = all[i] ?: continue
+            if (t === Thread.currentThread()) continue
+            val name = t.name
+            if (name.endsWith(suffix) || name == "VmRunner:${id.text}") {
+                try { t.join(500L) } catch (_: InterruptedException) { Thread.currentThread().interrupt() }
+            }
+        }
     }
 
     /**
@@ -520,7 +550,7 @@ class VM(
 //        println("peek $addr -> ${offset}@${memspace?.javaClass?.canonicalName}")
 
         return if (memspace == null)
-            throw NullPointerException()//null
+            throw OpenBusException(addr)//null
         else if (memspace is UnsafePtr) {
             if (addr >= memspace.size)
                 throw ErrorIllegalAccess(this, addr)
@@ -535,7 +565,7 @@ class VM(
         val (memspace, offset) = translateAddr(addr)
 
         return if (memspace == null)
-            throw NullPointerException()//null
+            throw OpenBusException(addr)//null
         else if (memspace is UnsafePtr) {
             if (addr >= memspace.size)
                 throw ErrorIllegalAccess(this, addr)
@@ -554,7 +584,7 @@ class VM(
         val (memspace, offset) = translateAddr(addr)
 
         return if (memspace == null)
-            throw NullPointerException()//null
+            throw OpenBusException(addr)//null
         else if (memspace is UnsafePtr) {
             if (addr >= memspace.size)
                 throw ErrorIllegalAccess(this, addr)
@@ -579,7 +609,7 @@ class VM(
         val (memspace, offset) = translateAddr(addr)
 
         return if (memspace == null)
-            throw NullPointerException()//null
+            throw OpenBusException(addr)//null
         else if (memspace is UnsafePtr) {
             if (addr >= memspace.size)
                 throw ErrorIllegalAccess(this, addr)
@@ -782,7 +812,9 @@ class VM(
             if (fromRel + len > 1048576) return null
 
             return if (dev is AudioAdapter) {
-                if (relPtrInDev(fromRel, len, 0, 114687)) dev.sampleBin.ptr + fromRel - 0
+                // Sample-bin window: 0..524287 maps into the 8 MB pool through MMIO 46.
+                if (relPtrInDev(fromRel, len, 0, 524287))
+                    dev.sampleBin.ptr + dev.sampleBank.toLong() * AudioAdapter.SAMPLE_BANK_SIZE + fromRel
                 else null
             }
             else if (dev is GraphicsAdapter) {
@@ -824,3 +856,10 @@ class PeripheralEntry2(
 )
 
 internal fun Int.kB() = this * 1024L
+
+fun Long.memAddrToReadable() = "'${this}' (bank " + this.absoluteValue.minus(if (this < 0) 1 else 0).div(1048576) +
+" offset " + this.absoluteValue.minus(if (this < 0) 1 else 0).mod(1048576) + ")"
+
+class OpenBusException(addr: Long) : NullPointerException(
+    "Address ${addr.memAddrToReadable()} is open bus"
+)

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

@@ -62,7 +62,9 @@ class VMJSR223Delegate(private val vm: VM) {
 //            System.err.println("MEMORY dev=${dev.typestring}, fromIndex=$fromIndex, fromRel=$fromRel")
 
             return if (dev is AudioAdapter) {
-                if (relPtrInDev(fromRel, len, 0, 114687)) dev.sampleBin.ptr + fromRel - 0
+                // Sample-bin window: 0..524287 maps into the 8 MB pool through MMIO 46.
+                if (relPtrInDev(fromRel, len, 0, 524287))
+                    dev.sampleBin.ptr + dev.sampleBank.toLong() * AudioAdapter.SAMPLE_BANK_SIZE + fromRel
                 else null
             }
             else if (dev is GraphicsAdapter) {
@@ -303,7 +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/VMSetupBroker.kt

@@ -22,6 +22,16 @@ object VMSetupBroker {
      * @param coroutineJobs Hashmap on the host of VMs that holds the coroutine-job object for the currently running VM-instance. Key: Int(VM's identifier), value: [kotlin.coroutines.Job]
      */
     fun initVMenv(vm: VM, profileJson: JsonValue, profileName: String, gpu: GraphicsAdapter, vmRunners: HashMap<VmId, VMRunner>, coroutineJobs: HashMap<VmId, Thread>, whatToDoOnVmException: (Throwable) -> Unit) {
+        // Refuse to start a new runner while the previous one is still alive:
+        // running both concurrently would race on the VM's memory / IO and lead
+        // to mixed text input, garbled rendering, and SIGSEGV on disposed peripherals.
+        coroutineJobs[vm.id]?.let { old ->
+            if (old.isAlive) {
+                System.err.println("[VMSetupBroker] previous runner for ${vm.id} is still alive; tearing it down before re-init")
+                killVMenv(vm, vmRunners, coroutineJobs)
+            }
+        }
+
         vm.init()
 
         try {
@@ -61,9 +71,38 @@ object VMSetupBroker {
      */
     fun killVMenv(vm: VM, vmRunners: HashMap<VmId, VMRunner>, coroutineJobs: HashMap<VmId, Thread>) {
 
+        // Order is critical: stop ALL execution first, then dispose peripherals.
+        // If we disposed peripherals while the runner thread is still alive, the
+        // thread would touch destroyed UnsafePtrs and SIGSEGV.
+
+        // 1. Stop parallel/child contexts. park() interrupts and joins them.
         vm.park()
         vm.poke(-90L, -128)
 
+        // 2. Interrupt the main runner thread and cancel the GraalVM context.
+        //    context.close(true) cancels in-flight script evaluation.
+        val runnerThread = coroutineJobs[vm.id]
+        runnerThread?.interrupt()
+        try { vmRunners[vm.id]?.close() } catch (_: Throwable) {}
+
+        // 3. Wait for the main runner thread to actually finish.
+        if (runnerThread != null && runnerThread !== Thread.currentThread()) {
+            try {
+                runnerThread.join(2000L)
+                if (runnerThread.isAlive) {
+                    // Last resort: re-interrupt and accept that disposal will
+                    // happen with the thread still alive. This is logged so
+                    // diagnostics surface a stuck VM rather than failing silently.
+                    System.err.println("[VMSetupBroker] runner ${vm.id} did not exit within 2s; proceeding anyway")
+                    runnerThread.interrupt()
+                }
+            }
+            catch (_: InterruptedException) {
+                Thread.currentThread().interrupt()
+            }
+        }
+
+        // 4. Now it's safe to release native resources held by peripherals.
         for (i in 1 until vm.peripheralTable.size) {
             try {
                 vm.peripheralTable[i].peripheral?.dispose()
@@ -71,8 +110,9 @@ object VMSetupBroker {
             catch (_: Throwable) {}
         }
 
-        coroutineJobs[vm.id]?.interrupt()
-        vmRunners[vm.id]?.close()
+        // 5. Drop runner / job handles so a subsequent initVMenv won't see stale entries.
+        vmRunners.remove(vm.id)
+        coroutineJobs.remove(vm.id)
 
         vm.getPrintStream = { TODO() }
         vm.getErrorStream = { TODO() }

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

@@ -45,6 +45,7 @@ class CLCDDisplay(assetsRoot: String, vm: VM) : GraphicsAdapter(assetsRoot, vm,
         shader: ShaderProgram?,
         uiFBO: FrameBuffer?
     ) {
+        if (disposed) return
         batch.shader = null
         batch.inUse {
             batch.color = Color.WHITE

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

@@ -40,6 +40,7 @@ class CharacterLCDdisplay(assetsRoot: String, vm: VM) : GraphicsAdapter(assetsRo
         shader: ShaderProgram?,
         uiFBO: FrameBuffer?
     ) {
+        if (disposed) return
         batch.shader = null
         batch.inUse {
             batch.color = Color.WHITE

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

@@ -942,7 +942,11 @@ open class GraphicsAdapter(private val assetsRoot: String, val vm: VM, val confi
         try { this.dispose() } catch (_: GdxRuntimeException) {} catch (_: IllegalArgumentException) {}
     }
 
+    @Volatile var disposed = false; private set
+
     override fun dispose() {
+        if (disposed) return
+        disposed = true
         //testTex.dispose()
 //        paletteShader.tryDispose()
 //        textShader.tryDispose()
@@ -986,6 +990,11 @@ open class GraphicsAdapter(private val assetsRoot: String, val vm: VM, val confi
     private val isRefSize = (WIDTH == 560 && HEIGHT == 448)
 
     open fun render(delta: Float, uiBatch: SpriteBatch, xoff: Float, yoff: Float, flipY: Boolean = false, shader: ShaderProgram? = null, uiFBO: FrameBuffer? = null) {
+        // Bail out if the adapter has already been torn down. Otherwise touching
+        // any of the disposed Pixmaps / Textures / native buffers below would
+        // raise a GdxRuntimeException or SIGSEGV.
+        if (disposed) return
+
         uiFBO?.end()
 
 
@@ -1362,8 +1371,12 @@ open class GraphicsAdapter(private val assetsRoot: String, val vm: VM, val confi
             textCursorIsOn = !textCursorIsOn
         }
 
-        // force light cursor up while typing
-        textCursorIsOn = textCursorIsOn || ((1..254).any { Gdx.input.isKeyPressed(it) })
+        // force light cursor up while typing -- only honour global key state when
+        // this VM is the focused viewport; otherwise hidden VMs would react to
+        // keypresses meant for the focused one.
+        if (Gdx.input.inputProcessor === vm.getIO()) {
+            textCursorIsOn = textCursorIsOn || ((1..254).any { Gdx.input.isKeyPressed(it) })
+        }
 
 
     }
@@ -1439,7 +1452,7 @@ in vec2 v_texCoords;
 uniform sampler2D u_texture;
 uniform vec4 pal[256];
 
-float intensitySteps = 4.0;
+float intensitySteps = 32.0;
 uniform vec4 lcdBaseCol;
 
 void main(void) {
@@ -1961,7 +1974,7 @@ void main() {
 
 
         val DEFAULT_PALETTE = intArrayOf( // 0b rrrrrrrr gggggggg bbbbbbbb aaaaaaaa
-            255,
+            119,
             17663,
             35071,
             48127,

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
@@ -280,29 +303,60 @@ 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
 
     fun update(delta: Float) {
+        // Only the VM whose IOSpace is wired up as the active InputProcessor (i.e. the
+        // currently focused viewport) may observe global keyboard/mouse state. Otherwise
+        // hidden VMs would all see the same keypresses as the focused one.
+        val isFocused = Gdx.input.inputProcessor === this
+
         if (rawInputFunctionLatched) {
             rawInputFunctionLatched = false
 
-            // store mouse info
-            mouseX = (Gdx.input.x + guiPosX).toShort()
-            mouseY = (Gdx.input.y + guiPosY).toShort()
-            mouseDown = Gdx.input.isTouched
-
-            // strobe keys to fill the key read buffer
-            var keysPushed = 0
             keyEventBuffers.fill(0)
-            for (k in 1..254) {
-                if (Gdx.input.isKeyPressed(k)) {
-                    keyEventBuffers[keysPushed] = k.toByte()
-                    keysPushed += 1
-                }
 
-                if (keysPushed >= 8) break
+            if (isFocused) {
+                // 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
+                for (k in 1..254) {
+                    if (Gdx.input.isKeyPressed(k)) {
+                        keyEventBuffers[keysPushed] = k.toByte()
+                        keysPushed += 1
+                    }
+
+                    if (keysPushed >= 8) break
+                }
+            }
+            else {
+                mouseButtons = 0
             }
         }
 
@@ -316,26 +370,33 @@ class IOSpace(val vm: VM) : PeriBase("io"), InputProcessor {
             rtc = vm.worldInterface.currentTimeInMills()
         }
 
-        // SIGTERM key combination: Ctrl+Shift+T+R
-        vm.stopDown = (Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) &&
-                Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) &&
-                Gdx.input.isKeyPressed(Input.Keys.T) &&
-                Gdx.input.isKeyPressed(Input.Keys.R)) || Gdx.input.isKeyPressed(Input.Keys.PAUSE)
-        if (vm.stopDown) println("[VM-${vm.id}] SIGTERM requested")
+        if (isFocused) {
+            // SIGTERM key combination: Ctrl+Shift+T+R
+            vm.stopDown = (Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) &&
+                    Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) &&
+                    Gdx.input.isKeyPressed(Input.Keys.T) &&
+                    Gdx.input.isKeyPressed(Input.Keys.R)) || Gdx.input.isKeyPressed(Input.Keys.PAUSE)
+            if (vm.stopDown) println("[VM-${vm.id}] SIGTERM requested")
 
-        // RESET key combination: Ctrl+Shift+R+S
-        vm.resetDown = Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) &&
-                Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) &&
-                Gdx.input.isKeyPressed(Input.Keys.R) &&
-                Gdx.input.isKeyPressed(Input.Keys.S)
-        if (vm.resetDown) println("[VM-${vm.id}] RESET requested")
+            // RESET key combination: Ctrl+Shift+R+S
+            vm.resetDown = Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) &&
+                    Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) &&
+                    Gdx.input.isKeyPressed(Input.Keys.R) &&
+                    Gdx.input.isKeyPressed(Input.Keys.S)
+            if (vm.resetDown) println("[VM-${vm.id}] RESET requested")
 
-        // SYSRQ key combination: Ctrl+Shift+S+Q
-        vm.sysrqDown = (Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) &&
-                Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) &&
-                Gdx.input.isKeyPressed(Input.Keys.Q) &&
-                Gdx.input.isKeyPressed(Input.Keys.S)) || Gdx.input.isKeyPressed(Input.Keys.PRINT_SCREEN)
-        if (vm.sysrqDown) println("[VM-${vm.id}] SYSRQ requested")
+            // SYSRQ key combination: Ctrl+Shift+S+Q
+            vm.sysrqDown = (Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) &&
+                    Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) &&
+                    Gdx.input.isKeyPressed(Input.Keys.Q) &&
+                    Gdx.input.isKeyPressed(Input.Keys.S)) || Gdx.input.isKeyPressed(Input.Keys.PRINT_SCREEN)
+            if (vm.sysrqDown) println("[VM-${vm.id}] SYSRQ requested")
+        }
+        else {
+            vm.stopDown = false
+            vm.resetDown = false
+            vm.sysrqDown = false
+        }
     }
 
     override fun touchUp(p0: Int, p1: Int, p2: Int, p3: Int): Boolean {
@@ -358,8 +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/MP2Env.kt

@@ -43,6 +43,7 @@ package net.torvald.tsvm.peripheral
 
 import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.toUint
 import net.torvald.tsvm.VM
+import net.torvald.tsvm.memAddrToReadable
 import java.util.*
 import kotlin.collections.ArrayList
 import kotlin.math.ceil
@@ -398,7 +399,7 @@ class MP2Env(val vm: VM) {
         };
         // check for valid header: syncword OK, MPEG-Audio Layer 2
         if ((syspeek(mp2_frame!!) != 0xFF) || ((syspeek(mp2_frame!! + 1*incr) and 0xFE) != 0xFC)){
-            throw Error("Invalid MP2 header at $mp2_frame: ${syspeek(mp2_frame!!).toString(16)} ${syspeek(mp2_frame!! + 1*incr).toString(16)}")
+            throw Error("Invalid MP2 header at ${(mp2_frame as Long).memAddrToReadable()}: ${syspeek(mp2_frame!!).toString(16)} ${syspeek(mp2_frame!! + 1*incr).toString(16)}")
         };
 
         // set up the bitstream reader