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BIOS Files

nickybmon edited this page Mar 31, 2026 · 1 revision

BIOS Files

Some systems require BIOS files to emulate — these are firmware dumps from the original hardware. Without them, the system will not run at all or will run incorrectly.

Important: Do not manually copy files into the BIOS folder. The only supported installation method is drag-and-drop into the OpenEmu library window, same as adding a game. If a file isn't being accepted, the MD5 hash is wrong — you have incorrect files.


How to Install a BIOS

  1. Make sure the relevant system core is installed (check OpenEmu → Preferences → Cores).
  2. Drag and drop the BIOS file onto your OpenEmu library window — just like adding a ROM.
  3. OpenEmu will validate the file and copy it to the correct location automatically.

If OpenEmu alerts you that a BIOS is needed, it means it couldn't find a valid file — recheck the filename and MD5.


Verifying MD5 Checksums

BIOS files must match the exact MD5 listed below. To check yours:

md5 /path/to/bios/file

In Terminal, you can drag the file onto the window instead of typing the path.


Required BIOS Files

Atari 5200

Core File MD5
Atari800 5200.rom 281f20ea4320404ec820fb7ec0693b38

Atari Lynx

Core File MD5
Mednafen lynxboot.img fcd403db69f54290b51035d82f835e7b

Famicom Disk System

Core File MD5
Nestopia disksys.rom ca30b50f880eb660a320674ed365ef7a

Intellivision

Core File MD5
Bliss exec.bin (Executive ROM — required) 62e761035cb657903761800f4437b8af
Bliss grom.bin (Graphics ROM — required) 0cd5946c6473e42e8e4c2137785e427f
Bliss ivoice.bin (Intellivoice — optional) d5530f74681ec6e0f282dab42e6b1c5f
Bliss ecs.bin (Entertainment Computer System — optional) 2e72a9a2b897d330a35c8b07a6146c52

Odyssey² / Videopac

Core File MD5
O2EM o2rom.bin 562d5ebf9e030a40d6fabfc2f33139fd

PlayStation

All three regional variants are supported. You only need the one(s) matching your game's region, but having all three is recommended.

Core File Region MD5
Mednafen scph5500.bin Japan (v3.0) 8dd7d5296a650fac7319bce665a6a53c
Mednafen scph5501.bin North America (v3.0) 490f666e1afb15b7362b406ed1cea246
Mednafen scph5502.bin Europe (v3.0) 32736f17079d0b2b7024407c39bd3050

Sega CD / Mega-CD

Core File Region MD5
Genesis Plus GX BIOS_CD_E.bin Europe (v1.00) e66fa1dc5820d254611fdcdba0662372
Genesis Plus GX BIOS_CD_J.bin Japan (v1.00p Rev E) 278a9397d192149e84e820ac621a8edd
Genesis Plus GX BIOS_CD_U.bin USA (v1.10 Rev B) 2efd74e3232ff260e371b99f84024f7f

Sega Dreamcast

The Dreamcast requires two BIOS files. Both must be present.

Core File Notes
Flycast dc_boot.bin Main boot ROM (~2 MB)
Flycast dc_flash.bin Flash ROM (~128 KB)

MD5 hashes vary by hardware revision. Most commonly circulated dumps will work. If you have the files and Dreamcast still doesn't launch, double-check both files are present in the BIOS folder (~/Library/Application Support/OpenEmu/Flycast/).


Sega Saturn

Core File Region MD5
Mednafen sega_101.bin Japan (v1.01, 1994-12-28) 85ec9ca47d8f6807718151cbcca8b964
Mednafen mpr-17933.bin North America / Europe (v1.01a) 3240872c70984b6cbfda1586cab68dbe

SNES (coprocessor ROMs)

Only needed for three specific games. Most SNES games do not require any BIOS.

Core File Game MD5
BSNES/Snes9x dsp3.rom SD Gundam GX 484908d68405d44e2be757b4e1e75d15
BSNES/Snes9x st011.rom Hayazashi Nidan Morita Shogi 5c209ce0283632b6574ad835bf862bee
BSNES/Snes9x st018.rom Hayazashi Nidan Morita Shogi 2 dafae0e0c71c924075811c595c61a30e

TurboGrafx-CD / PC Engine CD

Core File MD5
Mednafen syscard3.pce 38179df8f4ac870017db21ebcbf53114

Use the Japan BIOS — the US version won't play some Japan-region games.

If your syscard3.pce has MD5 ff1a674273fe3540ccef576376407d1d, it contains a 512-byte header and needs to be stripped:

dd bs=512 skip=1 if=syscard3.pce of=syscard3fix.pce

Use syscard3fix.pce going forward.


Systems That Do NOT Need BIOS Files

These systems work out of the box with no BIOS required:

Atari 2600, Atari 7800, Atari Jaguar, ColecoVision, Game Boy / GBC, Game Boy Advance, Game Gear, MSX, NES / Famicom, Nintendo 64, Pokémon Mini, Sega 32X, Sega Genesis / Mega Drive, Sega Master System, Sony PSP, Super Nintendo (SNES), Vectrex, Watara Supervision, WonderSwan, 3DO

PSP note: PPSSPP does not need a PSP firmware file to run most games. It has its own built-in HLE BIOS.

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