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SMS Plus GX - RetroBIOS
Type standalone + libretro
Classification Enhanced forks
Source https://github.com/libretro/smsplus-gx
Upstream https://github.com/ekeeke/smsplus-gx
Version 1.8
Profiled 2026-03-25
Cores smsplus, smsplus_gx
Systems sega-master-system, sega-game-gear, colecovision, sega-sg1000, sord-m5
Technical notes

Enhanced fork of Charles MacDonald's SMS Plus 1.3 by Eke-Eke (GX) and gameblabla. Master System, Game Gear, ColecoVision and SG-1000 emulator. Standalone ports also support Sord M5 (behind SORDM5_EMU compile flag, not compiled in libretro build).

BIOS loading in bios_init() (source/ports/libretro/smsplus_libretro.c:211-260). bios.sms is always attempted but only activated when core option smsplus_sms_bios is "auto" (default: disabled). BIOS.col is loaded only for ColecoVision ROMs and required for them. Standalone ports use BIOS.sms (uppercase) instead of bios.sms.

.info marks BIOS.col as optional (firmware1_opt=true) but the libretro code returns false from retro_load_game() when BIOS.col is missing for .col ROMs.

3 files | 1 required, 2 optional | 3 in repo, 0 missing

bios.sms optional in repo
Sega Master System boot ROM

BIOS.col required in repo
ColecoVision BIOS ROM

BIOS_sordm5.bin optional in repo standalone
Sord M5 BIOS ROM

  • System: sord-m5
  • Size: 8.0 KB
  • Source: source/ports/sdl/smsplus.c:321-329
  • Read as 0x2000 (8192) bytes into coleco.rom (shared buffer). Only in standalone builds (SORDM5_EMU define). Not compiled in libretro. Code does not enforce presence but system needs BIOS to function.

Generated on 2026-09-14T09:03:10Z