Four hypotheses tried and killed by measurement, recorded so the next session
does not repeat them: misrouted eng port (traced -- resolves correctly),
OneOfSeveral's DrawPixelMap8 branch (only OneOfSeveralPixInt uses it, and all
four instances are on the 6-bit colour port where it is correct), an 8-bit
value overflowing a 6-bit field (the bits are far too high), and a displaced
copy from elsewhere in the buffer (the rows appear nowhere else).
Observed structure: constant low byte, varying high byte -- one field written
correctly while another is garbage.
The next move is an instrument, not a fifth hypothesis: trace at the VIEW
layer and log every draw whose absolute position lands in the artifact rect,
with port, colour and call site. The rect is tiny so the log is short.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
CydandClaude Fable 5
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