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# ChimeraSNES - RetroBIOS

Type | libretro
Classification | community_fork
Source | https://github.com/jamsilva/chimerasnes
Upstream | https://github.com/snes9xgit/snes9x
Version |
Profiled | 2026-03-23
Cores | chimerasnes
Systems | nintendo-snes, nintendo-satellaview, nintendo-sufami-turbo

Technical notes

Based on multiple snes9x forks (uosnes, snes9x2005), optimized for slow hardware. All coprocessor data (DSP1-4, CX4, SuperFX, SA-1, SPC7110, OBC1) is HLE with embedded ROM tables. No external coprocessor firmware needed. BS-X BIOS loading controlled by core option chimerasnes_bsx_bios (default: skip). retro_load_game_special() returns false (no subsystem support). .info firmware_count absent (= 0), under-declares: code loads 2 files.

2 files | 1 required, 1 optional | 2 in repo, 0 missing

`BS-X.bin` -optional : Satellaview BS-X BIOS

- System: nintendo-satellaview
- Size: 1.0 MB
- Aliases: `BS-X.bios`
- Validation: size
- Source: `source/bsx.c:857-882`
- Platforms: batocera, lakka, recalbox, retroarch, retrobat, retrodeck, retropie
- Loaded by BSX_LoadBIOS() from system_dir when core option chimerasnes_bsx_bios is set to 'load' (default: skip). Tries BS-X.bin first, then BS-X.bios as fallback. Size must be BIOS_SIZE (0x100000). Many BS-X games run without it.

`STBIOS.bin` -required : Sufami Turbo BIOS

- System: nintendo-sufami-turbo
- Size: 256.0 KB
- Source: `source/memmap.c:275-289`
- Platforms: batocera, lakka, recalbox, retroarch, retrobat, retrodeck, retropie
- Loaded by LoadSFTBIOS() from system_dir when Sufami Turbo game detected (BANDAI SFC-ADX header at ROM offset 0, memmap.c:833). Reads 0x40000 bytes into Memory.ROM. No validation performed.

Generated on 2026-03-25T14:56:43Z