Slow chorded presses still glitch lamps at 62500 after three rounds of
host-side hardening (NAK-race resend -> stop-and-wait -> typed
resolution): a chord maximizes board ISR latency exactly when lamp
replies arrive, and a 2-byte RX buffer loses bytes no protocol can
recover. Full post-mortem in ANALYSIS.md; all bench evidence archived.
Final ladder: 9600 production / 31250v2 FastRIO / 62500 shelved /
125000 not viable. Stop-and-wait stays on everywhere as cheap delivery
insurance.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
CydandClaude Fable 5
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