Gearcoleco - RetroBIOS

Type	libretro
Classification	Official ports
Source	https://github.com/drhelius/Gearcoleco
Version	1.0.0
Profiled	2026-03-23
Cores	gearcoleco
Systems	colecovision

Technical notes

ColecoVision emulator by Ignacio Sanchez (drhelius). Official port maintained by the upstream author. The ColecoVision BIOS ROM is required. Without it, the core renders a static placeholder image (kNoBiosImage from no_bios.h) and games do not execute.

The libretro wrapper (platforms/libretro/libretro.cpp:295-308) tries "colecovision.rom" first, then falls back to "coleco.rom". Both resolve to the same LoadBios() call in src/Memory.cpp:256-287 which validates size == 0x2000 (8192 bytes) only. No hash check is performed.

On reset, BIOS byte at offset 0x69 is patched for region selection: 0x3C for NTSC, 0x32 for PAL (src/Memory.cpp:206-209).

SGM (Super Game Module) expanded RAM requires no additional BIOS files.

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

colecovision.rom required in repo

• System: colecovision
• Size: 8.0 KB
• Aliases: coleco.rom
• Validation: size
• Source: platforms/libretro/libretro.cpp:448-470, src/Memory.cpp:230-283
• Platforms: batocera, emudeck, lakka, retroarch, retrobat, retrodeck, retropie, romm

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