fixNES - RetroBIOS

Type	libretro
Classification	Official ports
Source	https://github.com/libretro/fixNES
Upstream	https://github.com/FIX94/fixNES
Version	Alpha v1.3.1
Profiled	2026-03-23
Cores	fixnes
Systems	nintendo-nes, nintendo-fds

Technical notes

fixNES is an NES/Famicom emulator by FIX94 (same author as fixGB).

FDS games require disksys.rom (8192 bytes) in the system directory. mapperInitFDS() in mapper.c:87-110 opens the file, validates exact size 0x2000, reads into fdsBIOS[]. Returns false if missing or wrong size. No hash validation.

Regular NES/NSF games need no BIOS.

No other system files loaded. system_dir accessed only for disksys.rom (libretro/libretro.c:277-285, doOpenFDSBIOS).

1 files | 1 required, 0 optional | 1 in repo, 0 missing

disksys.rom required in repo both
Family Computer Disk System BIOS

• System: nintendo-fds
• Size: 8.0 KB
• Validation: size
• Source: mapper.c:87-110 (mapperInitFDS), libretro/libretro.c:277-285 (doOpenFDSBIOS)
• Platforms: batocera, emudeck, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, romm

Generated on 2026-04-03T20:37:39Z