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O2EM - RetroBIOS
Type libretro
Classification Community forks
Source https://github.com/libretro/libretro-o2em
Upstream https://sourceforge.net/projects/o2em/
Version 1.18
Profiled 2026-03-24
Cores o2em_libretro
Systems odyssey2, videopac
Core ID o2em_libretro
Technical notes

Libretro port of O2EM, an Odyssey2/Videopac emulator by Daniel Boris and André de la Rocha. Port by Arlindo M. de Oliveira.

One BIOS ROM selected via o2em_bios core option (default o2rom.bin). Loaded into rom_table[0] (1024 bytes), identified by CRC32. vpp=1 for Videopac+ variants (g7400.bin, jopac.bin). Core fails to load without the selected BIOS.

Voice module ("The Voice" speech synthesis add-on) emulation via WAV samples in system/voice/. 9 banks × 128 samples, named {bank}{sample}.WAV (e.g. E480.WAV). Compiled with HAVE_VOICE=1 on most platforms. Optional: core works without samples, speech is silently skipped.

BIOS loading: libretro.c load_bios() lines 145-212. BIOS selection: libretro_core_options.h lines 52-64. Voice loading: voice.c init_voice() lines 38-79, called from libretro.c:1025-1032.

5 files | 4 required, 1 optional | 5 in repo, 0 missing Categories: 4 BIOS, 1 game data

o2rom.bin required in repo north-america

c52.bin required in repo europe

g7400.bin required in repo europe

jopac.bin required in repo france

voice/ optional in repo game_data

  • Source: voice.c:38-79, libretro.c:1025-1032
  • The Voice speech synthesis WAV samples. 9 banks (E4, E8-EF) × 128 samples.

Generated on 2026-04-18T08:05:07Z