Captures everything learned in the 2026-05-20 session before scope
forced a pause:
- Block framing is solved: 32-byte blocks, one per histogram
interval, signature byte pattern `[22:24]=0x0000` +
`[28:32]=0x1e 0x0a 0x00 0x00` reliably identifies data blocks.
- Block count = interval count (791 blocks in N844L20G.630H for
a TXT-reported 792 intervals).
- Sample[0] = Tran peak in 0.0005 in/s/count units (verified on
one event — needs cross-event confirmation).
- Samples 1-8 → channel/metric mapping is still open. None of
the obvious layouts (peak-then-freq alternating, all-peaks-
then-all-freqs, per-channel 3-tuples) match the TXT values
across multiple blocks. Likely needs a higher-activity
fixture (current N844 corpus is all noise-floor data) to
disambiguate.
- `>100 Hz` sentinel encoding in the binary is unknown.
- 4-byte variable metadata field at block[24:28] needs
correlation work against TXT columns.
Doc mirrors the structure of docs/waveform_codec_re_status.md so
a future RE session has a familiar entry point. Includes the
suggested attack plan + the code seam where the eventual decoder
will land (minimateplus/histogram_codec.py).
The §7.6.2 spec in instantel_protocol_reference.md is structurally
correct but doesn't pin down per-sample semantics — this doc
supersedes it where they conflict on confidence level.
No code shipped on this branch. When the codec is cracked, the
plan is to land minimateplus/histogram_codec.py + wire into
event_file_io.read_blastware_file() + remove the has_samples
short-circuit from scripts/backfill_sidecars.py.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
