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--- music_file_format [2026/02/02 13:17] – appledog
+++ music_file_format [2026/02/02 13:35] (current) – appledog
@@ Line 2: / Line 2: @@
 How to do it?
-== Proposal 1
+== Proposal 1: Text file
+* on a row:  CWND CWND CWND CWND
+* "Channel, Waveform, Note, Duration" ex 12G4Q is channel 1, waveform 2, note G4, quarter note
+* Can have commands like TEMPO = 90 and ROW=HalfNote (meaning 180 rows/minute for Tempo=90)
+** This would require auto-shutoff of notes/a polling player (could be done using Int 11h music timers)
+== Proposal 2 (Data-File)
 MUSIC FILE FORMAT v1.0\\
 ======================
@@ Line 16: / Line 23: @@
 ** +9:  [7] Reserved
-* Instrument Table (8 bytes each):
+* Instrument Table (10 bytes each):
-** +0:  [1] Waveform (WAVE_xx constant)
+** +0:  [1] Instrument ID
-** +1:  [1] Pulse width / duty cycle
+** +1:  [1] Instrument Type
-** +2:  [1] Attack
+* Waveforms:
-** +3:  [1] Decay
+** +2:  [1] Waveform (WAVE_xx constant)
-** +4:  [1] Sustain
+** +3:  [1] Pulse width / duty cycle
-** +5:  [1] Release
+** +4:  [1] Attack
-** +6:  [1] Default volume
+** +5:  [1] Decay
-** +7:  [1] Reserved
+** +6:  [1] Sustain
+** +7:  [1] Release
+** +8:  [1] Default volume
+** +9:  [1] Reserved
+* Samples:
+** +2:  [1] address (bank)
+** +3:  [1] address (low byte)
+** +4:  [1] address (high byte)
+** +5:  [1] Volume
+** +6:  [1] Playback speed
+** +7:  [1] reserved
+** +8:  [1] reserved
+** +9:  [1] reserved
+NOTE: need to do more research on what data we should include with samples. How does SNES/etc. do it?
 * Order List (1 byte each):
@@ Line 37: / Line 58: @@
 === Row Command Format
-* Command Byte:
+Command Byte:
-** Bits 7-6: Channel (0-3)
+* Bits 7-6: Channel (0-3)
-** Bits 5-4: Command type
+* Bits 5-4: Command type
-** Bits 3-0: Depends on command type
+* Bits 3-0: Depends on command type
+OR
+* Command Byte
+* Channel Byte
+* Data Word + Data Word + Data Word (Reserved)
 Command Types:
@@ Line 51: / Line 77: @@
 * 11 = Effect (3 bytes)
 ** [Cmd] [Effect Type] [Effect Param]
+=== Note data
+* $00 = Rest (no change)
+* $01-$60 = Notes (C0 to B7)
+* $61 = Note off
+* $FF = End of pattern
+* Note calculation:
+** Note = (Octave * 12) + Semitone + 1
+** C4 = (4 * 12) + 0 + 1 = 49 = $31
+** A4 = (4 * 12) + 9 + 1 = 58 = $3A
+=== Example Data File
+<codify armasm>
+; ============================================================================
+; Simple test song: C-E-G-C chord progression
+; ============================================================================
+music_test_song:
+; Header (16 bytes)
+music_header:
+    .bytes "SD"             ; Magic
+    .byte 1                 ; Version
+    .byte 0                 ; Flags
+    .word 250               ; Tempo: 250ms per row (240 BPM)
+    .byte 2                 ; 2 instruments
+    .byte 2                 ; 2 patterns
+    .byte 4                 ; 4 orders (play pattern 0, 1, 0, 1)
+    .fill 7, 0              ; Reserved
+; Instruments (8 bytes each)
+music_instruments:
+    ; Instrument 0: Lead (pulse wave)
+    .byte WAVE_PULSE        ; Waveform
+    .byte $40               ; 50% duty
+    .byte $10               ; Attack
+    .byte $20               ; Decay
+    .byte $80               ; Sustain
+    .byte $40               ; Release
+    .byte $C0               ; Volume
+    .byte 0                 ; Reserved
+    ; Instrument 1: Bass (triangle)
+    .byte WAVE_TRIANGLE     ; Waveform
+    .byte 0                 ; Duty (ignored for triangle)
+    .byte $08               ; Attack
+    .byte $10               ; Decay
+    .byte $A0               ; Sustain
+    .byte $30               ; Release
+    .byte $FF               ; Volume
+    .byte 0                 ; Reserved
+; Order list
+music_orders:
+    .byte 0                 ; Play pattern 0
+    .byte 1                 ; Play pattern 1
+    .byte 0                 ; Play pattern 0 again
+    .byte 1                 ; Play pattern 1 again
+    .byte $FF               ; End of song
+; Patterns
+music_patterns:
+; Pattern 0 offset (for seeking)
+music_pattern_0:
+    ; Row 0: Channel 0 plays C4 with instrument 0
+    .byte $00, $31, $00     ; Ch0, Note On, C4, Inst 0
+    .byte $40, $19, $01     ; Ch1, Note On, C3, Inst 1 (bass)
+    .byte $FF               ; End of row
+    ; Row 1: Channel 0 plays E4
+    .byte $00, $35, $00     ; Ch0, Note On, E4, Inst 0
+    .byte $FF               ; End of row
+    ; Row 2: Channel 0 plays G4
+    .byte $00, $38, $00     ; Ch0, Note On, G4, Inst 0
+    .byte $FF               ; End of row
+    ; Row 3: Channel 0 plays C5
+    .byte $00, $3D, $00     ; Ch0, Note On, C5, Inst 0
+    .byte $FF               ; End of row
+    .byte $FF               ; End of pattern
+music_pattern_1:
+    ; Row 0: Note off on channel 0, bass plays G2
+    .byte $10               ; Ch0, Note Off
+    .byte $40, $14, $01     ; Ch1, Note On, G2, Inst 1
+    .byte $FF               ; End of row
+    ; Row 1: Channel 0 plays G4
+    .byte $00, $38, $00     ; Ch0, Note On, G4, Inst 0
+    .byte $FF               ; End of row
+    ; Row 2: Channel 0 plays B4
+    .byte $00, $3C, $00     ; Ch0, Note On, B4, Inst 0
+    .byte $FF               ; End of row
+    ; Row 3: Channel 0 plays D5
+    .byte $00, $3F, $00     ; Ch0, Note On, D5, Inst 0
+    .byte $FF               ; End of row
+    .byte $FF               ; End of pattern
+music_end:
+</codify>