bc5a7a9fec
The previous Xodnizel implementation modeled the FDS modulator unit's output via a bit-serial b8shiftreg88 mechanism but omitted the modulator's sweep-bias accumulator entirely. Real hardware accumulates each modulator output cycle's bias step into a signed 11-bit register; the running total scales the carrier frequency. Without it, music that programs a slowly-developing modulation waveform (e.g. VS. Excitebike's FDS triangle voice) gets a static off-pitch note instead of the intended pitch sweep. Bias-table value fix in2a91d40corrected per-step values used inside the broken model but did not address the structural omission; testing on Vs. Excitebike (Japan) showed essentially zero audible change (race-window RMS vs the MDFN-derived reference moved 8371 -> 8365 on a 50-second capture - within noise). Replace the file wholesale with the MDFN-derived model from libretro/fceumm_next (negativeExponent, itself derived from Mednafen's NES FDS sound), adapted to fceumm's GameExpSound API and existing FDSSoundReset/StateAdd/Power/Write export surface so fds.c does not change. Differences from the _next version: - Uses upstream's openbus (X.DB) for FDS register read top bits instead of the OPENBUS=0x40 constant. - Drops the GetOutput() per-channel volume mixer (no equivalent in upstream). - Keeps FDSSoundReset/FDSSoundStateAdd/FDSSoundPower/FDSSoundWrite signatures unchanged for binary-compat with bootleg/conversion mappers. Validation on Vs. Excitebike (Japan) FDS, side B / ORIGINAL EXCITE, 50-second race-window capture vs the _next reference: - upstream master (2a91d40): RMS=8371 - this patch: RMS=4957 (41% closer) Spectrograms after the patch are visually aligned with the reference; the remaining gap is likely outside the FDS modulator (mixing / NES APU level). Performance: throughput on the same 9000-frame headless capture went 488 fps -> 485 fps (-0.6%, within measurement noise). The new model runs FDSClockUnits per CPU cycle versus the previous file's per-2-CPU clock, but compensates by replacing the master-volume integer divide with a 4-entry LUT and caching the wave sample between index transitions. Savestate compatibility: SFORMAT layout changes (new tags WFRQ/WPOS/ MFRQ/MPOS/SWBS/MCTL etc.; old tags B88/CLOC/B60/B66/B68/B76/SPSG/AMPL are dropped). Pre-existing FDS savestates will lose their audio register snapshot on load and revert to defaults; gameplay state and disk contents are unaffected.
FCE Ultra mappers modified
FCEU "mappers modified" is an unofficial build of FCEU Ultra by CaH4e3, which supports a lot of new mappers including some obscure mappers such as one for unlicensed NES ROM's.
Sequential targets Light Guns support added
Support for Sequential targets Light Guns has been added. "Gun Aux A" serves as light sensor logic input.