Play is the scheduler: one tick, four cursors. Every voice keeps its own place in its own track and its own count of how much longer the note it is holding lasts, so a voice playing whole notes and a voice playing eighths cost the same and never have to know about each other. They share the tick and nothing else. That is what makes the tick the smallest subdivision in the piece rather than a note length - it is the only unit four parts can agree on. A track is pairs of bytes: what to play, then how many ticks it lasts. MIDI notes stop at 127, so the top of the byte was free and neither the rest nor the end marker had to be invented - 0 is a rest and 0xFF ends the track. Examples/tune.asm spent zero on its end marker and so could not write a rest at all, which one voice can live with and four cannot: the silences are what make them separate parts rather than a chord. The state is four bytes a voice, cursor first because that is what LDD and STD move - a pointer through a pointer, which is what lets this be a loop over four voices instead of the same code four times. CALL preserves A and DP0-2, so a caller says which voice it means in two instructions. The piece is four bars of C, F, G, C with the parts moving at four different rates, because that is the thing one channel cannot do. All four channels get the same instrument, which is exactly what M3 replaces. fourVoiceTest staggers two voices so each gets a stretch alone: middle C while the other rests, the octave while the first is silent, then both. The first two are measured for pitch and the third for level, because TWO NOTES CANNOT BE ASKED THEIR PITCH - the crossing counter adds them and answers 785 hertz, which is 262 plus 523 and a fact about nothing. Verified with break.sh: dropping the channel select trips one check, pointing both voices at one cursor trips three. It shares Play's design and not its code, and is smaller - no track ends in it, so there is no live flag and no count of what is still playing. Play.sbx on the disk is why ten recordings moved: one added line each, and the file count with it. Nothing else in them changed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
44 lines
1.0 KiB
Plaintext
44 lines
1.0 KiB
Plaintext
CosmOS
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> dir
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greet.sbx 211
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hello.sbx 53
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Life.sbx 1396
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Snake.sbx 2164
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Keys.sbx 664
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Say.sbx 156
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Break.sbx 149
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Grid.sbx 571
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Press.sbx 872
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Mode.sbx 48
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Flip.sbx 173
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Sprite.sbx 442
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Depth.sbx 672
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Lander.sbx 9201
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Pad.sbx 264
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Crash.sbx 632
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vars.script 50
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blocks.script 343
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loops.script 272
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tune.sbx 318
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Play.sbx 446
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notes.txt 21
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Apps <dir>
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hi.script 121
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bad.script 45
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plain.script 24
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cross.script 280
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nonl.script 38
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outer.script 376
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inner.script 44
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loop.script 35
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30 files, 1 directory
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> load Say.sbx
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loaded, starting at 5000
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> run the disk took its time
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it says: the disk took its time
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finished
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> exit
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halted
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Execution halted.
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[exit 0]
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