mpckit/pull-requests/checkpoint-a-results/checkpoint-a-results-and-device-limits.md

Checkpoint A results and device limits

Branch: checkpoint-a-results → main

What changed

Device checkpoint A passed on 2026-11-10 (run by bajdev; pack built from f36cda3), which completes M3. This records the results and uses the limits it found.

• Mute groups: MaxMuteGroup 32 → 16. The device offers none and 1-16. Pads written with 32 still choked, but the device treats the field as 1-16, so mpckit writes only 0-16.
• BPM: was "any positive number"; now 20-999 (MinBPM, MaxBPM), the device's tempo control range. All four test tempos (20, 30, 300, 999) worked.
• Bars: comment updated (64 bars confirmed). MaxBars stays 999 because the device maximum is still unknown.
• Pack builder: MpckitMute now uses groups 16 and 1, since 32 is refused. The README notes what the 2026-11-10 run used.
• Docs:
  • Format doc: new "Checkpoint A" results in section 7; mute group range added to section 5; open question 1a (tuning limits) closed; question 5 narrowed (extensible header confirmed).
  • Build plan: results under checkpoint A ("M3 is done"); validation rule for BPM and mute group; the WAV "not yet tested" note and the mute-group and tuning risk rows marked resolved.
  • tools/checkpoint-a/README.md: results table filled in.

Testing

go vet ./... and go test ./... pass. The tests now check that group 16 and BPM 20/999 are accepted and that group 17, BPM 19.9 and 999.5, NaN and infinity are refused. go run ./tools/checkpoint-a still builds the pack.