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SMS Plus GX - RetroBIOS
Type standalone + libretro
Classification enhanced_fork
Source https://github.com/libretro/smsplus-gx
Upstream https://github.com/ekeeke/smsplus-gx
Version 1.8
Profiled 2026-03-25
Cores smsplus
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() (smsplus_libretro.c:203-252). 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 | 2 in repo, 1 missing

bios.sms -optional : Sega Master System boot ROM

  • System: sega-master-system
  • Aliases: BIOS.sms
  • Source: smsplus_libretro.c:211-229
  • Platforms: lakka, retroarch, retrodeck, retropie
  • Loaded into bios.rom (up to 1 MB allocated). Only active when core option smsplus_sms_bios is "auto". Displays SMS startup screen before game execution. Standalone ports use BIOS.sms (uppercase).

BIOS.col -required : ColecoVision BIOS ROM

  • System: colecovision
  • Size: 8.0 KB
  • Source: smsplus_libretro.c:232-248
  • Platforms: lakka, retroarch, retrodeck, retropie
  • Required for ColecoVision games. Read as 0x2000 (8192) bytes into coleco.rom. Without this file, retro_load_game() returns false for .col files.

BIOS_sordm5.bin -optional, standalone, missing from repo : Sord M5 BIOS ROM

  • System: sord-m5
  • Size: 8.0 KB
  • 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 2026-03-25T14:56:43Z