BIOS Files

Some platforms require BIOS files to run games. BIOS files are system firmware that the original hardware used to boot and run software.

Why Are BIOS Files Needed?

Certain consoles had built-in firmware that games depended on. Without the correct BIOS, games for these platforms may not start or may behave incorrectly. Other platforms work fine without BIOS files — the emulator handles everything.

Uploading BIOS Files

Go to Settings > BIOS Files to manage your BIOS files. Each platform that supports BIOS files is listed with the specific files it needs.

To upload a BIOS file:

1. Find the platform section
2. Click on the file you want to upload
3. Select the file from your device
4. The file is automatically validated against the expected MD5 hash

A green checkmark means the file matches the expected hash. A red icon means the hash doesn't match — the file may still work, but it might be the wrong version.

Bulk Upload

You can upload many BIOS files at once using the bulk upload feature at the top of the BIOS settings page.

1. Drag and drop a folder of BIOS files, or click to browse
2. Files are automatically identified by their MD5 hash
3. A summary shows matched files, already-uploaded files, and unmatched files
4. Click Add files to upload all matched files at once

This is the fastest way to set up BIOS files if you have them in a folder.

Platforms Requiring BIOS

Required BIOS (games won't start without these)

Optional BIOS (enhances accuracy or enables features)

Missing BIOS Files

If a required BIOS file is missing, the game will fail to start. The error screen will suggest checking your BIOS files. For optional BIOS files, games will still run but may skip boot animations or have minor differences.

Before Adding BIOS Files

Save states created without a BIOS are not compatible with sessions that use a BIOS. If you've been playing without BIOS files and want to add them, follow these steps to avoid losing progress:

1. Disable the autoload save state feature for your game (see Saves)
2. Open your game and create an in-game save (use the game's own save menu, not a save state)
3. Upload your BIOS files following the steps above
4. Launch the game and load from your in-game save (not a save state)

From this point on, save states will be compatible with your BIOS setup.

Troubleshooting

• Game won't start: Check that all required BIOS files for the platform are uploaded and enabled
• Hash mismatch warning: The file may be a different version. Try sourcing the correct version matching the expected hash shown in settings
• BIOS file not recognized in bulk upload: The file's MD5 doesn't match any known BIOS. Try uploading it individually to the correct platform instead
• Game crashes after adding BIOS: Your save states from before aren't compatible. Load from an in-game save (SRAM) instead — see the steps above