b2 - RetroBIOS

Type	standalone + libretro
Source	https://github.com/zoltanvb/b2-libretro
Version	v0.1
Profiled	2026-03-18
Cores	b2
Systems	bbc-micro-b, bbc-micro-bplus, bbc-master-128, bbc-master-compact

No BIOS or firmware files required. This core is self-contained.

b2 is a BBC Micro emulator by Tom Seddon. Libretro port by Zoltan Balogh. ref: zoltanvb/b2-libretro, tom-seddon/b2

Standalone: loads ROMs from etc/roms/ via GetAssetPath(). ref: tom-seddon/b2/src/b2/roms.cpp:9-10

Libretro port (experimental): GetAssetPath stubbed in src/libretro/adapters.cpp to return relative paths. LoadFile also stubbed (returns false). ROM loading mechanism unclear — the 256 ROM files are in the repo but the stub suggests they may not load at runtime. is_experimental=true in .info. ref: zoltanvb/b2-libretro/src/libretro/adapters.cpp

256 ROM files in etc/roms/ cover: BBC Model B (OS 1.20, BASIC II), Model B+ (B+MOS), Master 128 (MOS 3.20, 3.50), Master Compact (MOS 5.00, 5.10, I5.10C/Olivetti), parasite processors (65C102 TUBE, 6502 TUBE), disc interfaces (Acorn 1770, Watford, Opus).

All ROMs ship with both standalone and libretro repos. No external BIOS files needed by the user for either mode.

Generated on 2026-03-20T19:12:20Z