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beeper: prescaler 32

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minjaesong
2026-06-20 21:10:28 +09:00
parent 646af9452c
commit 6c9a3fdc1e
4 changed files with 43 additions and 41 deletions
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29
assets/disk0/tvdos/bin/monplay.js
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@@ -14,21 +14,22 @@
// ---------------------------------------------------------------------------
// Beeper hardware (IOSpace). MMIO byte m is reached at JS address -(m+1):
// 93 RO -> reading uploads the staged command (the strobe)
// 94..99 -> PPPPPPPP / pppppp_QQ / qqAABBCC / aaaaaaaa / bbbbbbbb / cccccccc
// AA/BB/CC are the high two bits of the 10-bit arpeggio deltas A/B/C.
// The square wave is f = (3579545/16) / (2 * divider); divider 0 = silence.
// 94..99 -> PPPPPPPP / C_ppppp_QQ / AAABBBCC / aaaaaaaa / bbbbbbbb / cccccccc
// The 13-bit divider is PPPPPPPP:ppppp. The arpeggio deltas A/B/C are 11-bit:
// AAA/BBB are the high 3 bits of A/B; C's high 3 bits split as C(byte95 bit7):CC.
// The square wave is f = (3579545/32) / (2 * divider); divider 0 = silence.
// ---------------------------------------------------------------------------
const BEEP_UPLOAD = -94 // read MMIO 93 to upload
const BEEP_P_HI = -95 // MMIO 94: PPPPPPPP
const BEEP_P_LO = -96 // MMIO 95: pppppp_QQ
const BEEP_EXT = -97 // MMIO 96: qqAABBCC (high 2 bits of A/B/C)
const BEEP_P_LO = -96 // MMIO 95: C_ppppp_QQ
const BEEP_EXT = -97 // MMIO 96: AAABBBCC (high 3 bits of A/B, low 2 of C's high bits)
const BEEP_A = -98 // MMIO 97: aaaaaaaa (A low 8 bits)
const BEEP_B = -99 // MMIO 98: bbbbbbbb (B low 8 bits)
const BEEP_C = -100 // MMIO 99: cccccccc (C low 8 bits)
const BEEP_HALFCLOCK = (3579545.4545454545 / 16.0) / 2 // f = BEEP_HALFCLOCK / divider
const DIVIDER_MAX = 0x3FFF // 14-bit
const ARG_MAX = 0x3FF // 10-bit arpeggio delta
const BEEP_HALFCLOCK = (3579545.4545454545 / 32.0) / 2 // f = BEEP_HALFCLOCK / divider
const DIVIDER_MAX = 0x1FFF // 13-bit
const ARG_MAX = 0x7FF // 11-bit arpeggio delta
const QQ_NONE = 0, QQ_FOUR = 1, QQ_TWO = 2, QQ_THREE = 3 // beeper note-effect (QQ field)
@@ -36,9 +37,9 @@ function uploadBeeper(divider, effect, a, b, c) {
if (divider < 0) divider = 0
if (divider > DIVIDER_MAX) divider = DIVIDER_MAX
a &= ARG_MAX; b &= ARG_MAX; c &= ARG_MAX
sys.poke(BEEP_P_HI, (divider >> 6) & 0xFF)
sys.poke(BEEP_P_LO, ((divider & 0x3F) << 2) | (effect & 3))
sys.poke(BEEP_EXT, (((a >> 8) & 3) << 4) | (((b >> 8) & 3) << 2) | ((c >> 8) & 3))
sys.poke(BEEP_P_HI, (divider >> 5) & 0xFF)
sys.poke(BEEP_P_LO, (((c >> 10) & 1) << 7) | ((divider & 0x1F) << 2) | (effect & 3))
sys.poke(BEEP_EXT, (((a >> 8) & 7) << 5) | (((b >> 8) & 7) << 2) | ((c >> 8) & 3))
sys.poke(BEEP_A, a & 0xFF)
sys.poke(BEEP_B, b & 0xFF)
sys.poke(BEEP_C, c & 0xFF)
@@ -100,9 +101,9 @@ const intervalHz = (interval) => NOTESHZ[clampInterval(interval)]
// subtraction. Returns either a single hardware command {sw:false, cmd:[...]}
// or, when the notes don't fit, a software-arpeggio plan {sw:true, dividers:[...]}.
// 1 note -> effect 0 (none)
// 2 notes -> effect 2 (single 10-bit delta A: only when <= 1023)
// 3 notes -> effect 3 (two 10-bit deltas: only when both <= 1023)
// 4 notes -> effect 1 (three 10-bit deltas: only when all <= 1023)
// 2 notes -> effect 2 (single 11-bit delta A: only when <= 2047)
// 3 notes -> effect 3 (two 11-bit deltas: only when both <= 2047)
// 4 notes -> effect 1 (three 11-bit deltas: only when all <= 2047)
// otherwise (wide chords / 5+ voices) -> software arpeggio over ALL the notes
// ---------------------------------------------------------------------------
function planMultiplex(dividers) {