Retro

Extract BIOS files from your own console

Some emulators won’t start without a BIOS: the basic software built into the console itself. That software is owned by the manufacturer and may not be freely distributed. That’s why we don’t host BIOS files on geekstation.nl and don’t link to them either. You get them from your own console. This guide explains how that works in broad terms and points to the official guides from the emulators.

Which emulator needs a BIOS?

Console Emulator BIOS
PlayStation 1 DuckStation Required
PlayStation 1 Beetle PSX HW (RetroArch) Not required: without BIOS it uses the built-in OpenBIOS
PlayStation 2 PCSX2 Required, no replacement exists
Nintendo DS melonDS Recommended, not required
Game Boy Advance mGBA Not required

Which files an emulator expects exactly, with the correct file names and checksums, is listed in the Libretro documentation on BIOS.

PlayStation 2 (PCSX2)

The PCSX2 guide Dumping BIOS describes it in two steps:

  1. Preparing your PS2 to run custom programs. PCSX2 recommends two softmods, FreeMcBoot (on a memory card) and FreeDVDBoot (on a DVD). These don’t permanently modify the console. Which one works depends on your PS2 model.
  2. Running a BIOS dumper. This is a small program that copies the BIOS from your console to a USB drive.

Then you copy the file to your PC and select the folder at the first start of PCSX2 (Setup Wizard → BIOS Image).

PlayStation 1 (DuckStation)

The developers of DuckStation write that you get a BIOS from your own console, including with the program Caetla “or another method.” The BIOS can be from any region or hardware version, but preferably choose the same region as your games, otherwise compatibility may decrease.

Using RetroArch with the core Beetle PSX HW? Then it works even without your own BIOS, with the built-in OpenBIOS. With your own BIOS (such as scph5500.bin for Japan, scph5501.bin for the US, and scph5502.bin for Europe) compatibility is better.

Nintendo DS (melonDS)

melonDS also works without a BIOS: it then uses a built-in replacement, which is less accurate. For the best compatibility you use the files from your own DS or DSi. The Libretro page on melonDS lists which files these are (including bios7.bin, bios9.bin, and firmware.bin). How to get them from your console is on the website and in the documentation of melonDS.

Verify your file

The Libretro documentation lists an md5 checksum for each BIOS file. With that checksum you can verify whether your dump was successful.

md5 filename.bin            # macOS
md5sum filename.bin         # Linux
certutil -hashfile filename.bin MD5   # Windows

Where do you put the BIOS?

  • RetroArch: in the system folder.
  • PCSX2: via Open BIOS Folder in the Setup Wizard or in the settings.
  • DuckStation: in the DuckStation user folder, under Settings → BIOS.
  • melonDS: in the emulation settings you select the paths to your files.

Warning

  • Never download a “BIOS pack.” It’s a copyright issue and such files are a known source of malware.
  • Preparing a console happens at your own risk. Softmods like FreeMcBoot don’t permanently modify the console, but a modchip does.
  • What’s legally allowed with your own copy for personal use varies by country, and circumventing protection may have its own rules. This is not legal advice. Find out for yourself what applies in your situation.
  • Don’t have a working console anymore? Then Beetle PSX HW and melonDS offer a fallback solution; for the PS2 that doesn’t exist.