The RIO drops comms if the analog-reply ACK is late by more than a few ms.
Empirically a slower CPU failed sooner, so the latency was dominated by how
fast the game processes the RIO packet and ACKs -- core=dynamic (recompiler)
+ cycles=max keeps the board in sync (user-confirmed). game_rio.conf passes
the real RIO through serial1=directserial realport:COM1.
With real control input the sim advances and then faults (null-ptr deref at
BTL4OPT.EXE CODE+0x123B) -- downstream of the minimal test.egg not setting the
arena objectpath, so VIDEO/GEO/ARENA/thr_tshd.bgf isn't found. That is content
config, separate from the now-working VPX protocol / renderer / RIO. Details
in RIO-NOTES.md.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>