Bench round 3 (testlogs/riomash-patched-62500-sw): lamp glitches
persisted because reply-resolution was type-blind — an analog reply
still crossing USB from the previous poll could falsely confirm the
NEXT command (usually a lamp write) before the board judged it. Now a
reply resolves only its MATCHING pending request (analog/version/
check); ACK/NAK stay type-blind, which is safe because the board's TX
ISR prioritizes ACK/NAK ahead of reply data, so a command's ACK cannot
trail into its successor's window. Budget-exhausted drops settle 10ms
before releasing the gate so late stragglers land on an empty pending.
New test: a stray AnalogReply must not resolve a pending lamp command.
283 green; selftest regression unchanged.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Bench falsified the v1 retransmit (testlogs/riomash-patched-62500-retx):
resends tracked NAKs 1:1 (321/321) yet lamps still stuck/missed — under
mash bursts the NAK arrives after a newer command is already "latest",
so the wrong packet was resent; and total shreds never NAK at all.
Now commands are stop-and-wait: ONE in flight (_commandGate), resolved
by ACK, NAK, or AckTimeout (50ms); NAK/timeout retransmits THE SAME
packet up to CommandRetransmitLimit (2), then drops (idempotent - the
next state update supersedes). Attribution is exact by construction and
timeouts catch silent shreds. Control-byte replies bypass the gate so
board traffic is never delayed; a request's own reply (analog/version/
check) also resolves the wait, so request/reply exchanges never burn
the timeout even if the board sends no explicit ACK.
7 tests (same-packet resend, timeout retry+drop, ACK completion,
serialization, reply-resolves-request, stray-NAK no-op, disable);
282 green. Mash summary now reports NAK/timeout resends.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The board ACK/NAKs every inbound packet; we were fire-and-forget, so
any corrupt arrival became a permanent state error (stuck-bright /
missed lamps at 62500, where ~6.5% of 4-byte lamp commands lose bytes
to RX-ISR overrun). Now a NAK control byte triggers a resend of the
most recent command packet, bounded by NakRetransmitLimit (default 2;
0 restores fire-and-forget).
Design notes: the wire has no sequence numbers, but every PC->RIO
command is idempotent (lamp state, analog request, reset), so resending
the latest command is safe even in the rare race where the NAK belonged
to an earlier packet. Single control-byte replies (our ACKs) never
participate. NakRetransmits counter surfaced in the mash summary.
6 new tests (retransmit, limit, budget reset, ACK no-op, control-byte
exclusion, disable switch); 281 green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Port the RIO wire protocol from legacy/riovjoy2.cpp into testable C#:
- Protocol/: command + length table, 7-bit checksum, packet builder, and a
streaming receive-side framing state machine (PacketParser) that mirrors the
legacy ReadCommBlock framing/resync (high-bit-mid-packet abort). Typed RIO->PC
decodes: AnalogReport (14-bit sign-extend), VersionInfo, CheckStatus; lamp-state
composition.
- Serial/: RioSerialLink drives an async receive loop with ACK/NAK reply policy
(legacy force-accept vs. opt-in VerifyInboundChecksum), the analog poll timer,
and the >5s reset-recovery watchdog. IRioTransport abstracts the COM port; the
SerialPort-backed transport does 9600 8N1 + DTR reset pulse, and acquire/release
is just create/dispose (foundation for native-game serial yield).
- tests/RioJoy.Core.Tests: 54 xUnit tests covering checksum, framing/resync,
builder round-trips, analog sign-extension + sentinel rejection, lamp combos,
and the read loop driven against an in-memory fake transport.
Hardware verification (version/check/analog against a cabinet) remains; it can't
be done off-device.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
CydandClaude Fable 5