How to Configure Multiple PS1 BIOS Files in RetroArch?

Missing or misconfigured PS1 BIOS files in RetroArch often cause game crashes, audio glitches, or black screens.

This guide solves that pain point by showing how to properly configure multiple BIOS files for PlayStation 1 emulation using RetroArch, ensuring smooth performance and full game compatibility.

What Is RetroArch and Why BIOS Files Matter?

RetroArch is a free, open-source frontend for emulators, game engines, and media players. It supports multiple platforms including Windows, macOS, Linux, Android, and iOS. For PlayStation 1 (PS1) emulation, RetroArch uses cores like Beetle PSX and PCSX ReARMed, which require BIOS files to function correctly.

What Is a BIOS File?

A BIOS (Basic Input/Output System) file is firmware that initializes hardware and software communication. For PS1 emulation, BIOS files replicate the original PlayStation console’s startup environment. Without them, many games won’t load or will behave unpredictably.

Why Use Multiple PS1 BIOS Files?

Different PS1 games were released in various regions—North America (NTSC-U), Europe (PAL), and Japan (NTSC-J). Each region uses a different BIOS version. Configuring multiple BIOS files ensures:

• Region compatibility
• Accurate emulation
• Reduced crashes and bugs
• Improved game performance

Supported PS1 BIOS Files in RetroArch

RetroArch supports the following official PS1 BIOS files:

Region	Filename	MD5 Checksum (for verification)
North America	scph1001.bin	924e392ed05558ffdb115408c263dccf
Europe	scph5502.bin	8dd7d5296a650fac731b3cbbecb78d8a
Japan	scph5500.bin	8dd7d5296a650fac731b3cbbecb78d8a
Japan (Alt)	scph7001.bin	1e68c231d0896b7eadcad1d7d8e5b0f1

Always verify BIOS files using MD5 checksums to ensure authenticity and avoid corrupted files.

How RetroArch Detects BIOS Files?

RetroArch automatically scans its system folder for BIOS files. If the correct files are present and named properly, the emulator loads them based on the game’s region. If BIOS files are missing or misnamed, RetroArch may fail to launch the game or display a warning.

Default BIOS Folder Path

• Windows: `C:\Users

\[YourName]\AppData\Roaming\RetroArch\system`

• macOS: /Users/[YourName]/Library/Application Support/RetroArch/system
• Linux: /home/[YourName]/.config/retroarch/system
• Android: /storage/emulated/0/RetroArch/system

Step-by-Step: Configure Multiple PS1 BIOS Files in RetroArch

Step 1: Download Verified BIOS Files

Only use BIOS files from trusted sources. Avoid pirated or modified versions. For legal reasons, BIOS files should be dumped from your own PlayStation console using tools like PSX BIOS Dumper.

Step 2: Rename BIOS Files Correctly

RetroArch requires exact filenames. Use the following names:

• scph1001.bin (USA)
• scph5500.bin (Japan)
• scph5502.bin (Europe)

Incorrect filenames will prevent RetroArch from recognizing the BIOS.

Step 3: Place BIOS Files in the System Folder

Move all BIOS files into the RetroArch system directory. Do not place them in the core or config folders.

Step 4: Verify BIOS Recognition

Open RetroArch and go to:

Main Menu → Information → Core Information → Beetle PSX

Check the “Missing BIOS” section. If all BIOS files are correctly placed, this section will be empty.

Testing BIOS Functionality

To confirm BIOS functionality:

1. Load a PS1 game from each region.
2. Observe the startup screen—each BIOS shows a different logo.
3. Check for smooth audio, proper framerate, and no graphical glitches.

If any issues occur, recheck the BIOS filenames and MD5 checksums.

Choosing the Right Core for PS1 Emulation

RetroArch offers two main cores for PS1:

Beetle PSX (Recommended for Accuracy)

• Supports high-resolution rendering
• Allows PGXP (geometry correction)
• Requires BIOS files for full functionality

PCSX ReARMed (Recommended for Low-End Devices)

• Optimized for ARM processors (e.g., Raspberry Pi, Android)
• Includes built-in HLE BIOS (not recommended for accuracy)
• Can run without BIOS but may cause compatibility issues

For best results, use Beetle PSX with verified BIOS files.

Performance Tips for PS1 Emulation

Enable PGXP Settings

PGXP improves 3D geometry accuracy. To enable:

Settings → Core → Enable PGXP

Use Vulkan or OpenGL Renderer

Choose the renderer based on your device:

• Vulkan: Better performance on modern GPUs
• OpenGL: More compatible with older systems

Adjust Internal Resolution

Increase resolution for sharper graphics:

Quick Menu → Options → Internal Resolution → x2, x4, x8

Troubleshooting BIOS Issues

Problem: Game Won’t Start

Solution: Check BIOS filenames and MD5 checksums. Ensure files are in the correct folder.

Problem: Black Screen or Audio Glitches

Solution: Use Beetle PSX core with verified BIOS files. Avoid HLE BIOS.

Problem: Region Mismatch

Solution: Use the correct BIOS file for the game’s region. NTSC-U games need scph1001.bin, PAL games need scph5502.bin.

Legal Note on BIOS Usage

BIOS files are copyrighted by Sony. Downloading them from the internet is illegal in many countries. To stay compliant:

• Dump BIOS from your own PlayStation console
• Use tools like BIOS Dumper v2.0
• Store files securely and avoid sharing

For more information, refer to Sony’s Intellectual Property Policy.

Advanced Configuration: Multiple BIOS Files for Multi-Disc Games

Some multi-disc PS1 games require BIOS switching during gameplay. RetroArch handles this automatically if all BIOS files are present.

How to Set Up Multi-Disc Games

1. Create an .m3u playlist file listing all disc .cue files.
2. Load the .m3u file in RetroArch.
3. RetroArch will switch discs using the correct BIOS based on region.

Ensure all discs are from the same region to avoid BIOS conflicts.

Mobile Setup: Configure PS1 BIOS on Android

Step-by-Step for Android Devices

1. Install RetroArch from Google Play Store.
2. Create a system folder in /storage/emulated/0/RetroArch/.
3. Place BIOS files inside the system folder.
4. Launch RetroArch and verify BIOS under Core Information.

Use PCSX ReARMed core for better performance on mobile, but BIOS files are still recommended.

RetroArch Core Updates and BIOS Compatibility

RetroArch updates may change BIOS requirements. Always check the Core Info after updates. If a BIOS file becomes incompatible:

• Download the latest core version
• Re-verify BIOS MD5 checksum
• Reconfigure BIOS folder if needed

Summary: Key Takeaways

• Use verified BIOS files: scph1001.bin, scph5500.bin, scph5502.bin
• Place BIOS files in the correct system folder
• Use Beetle PSX core for best accuracy
• Verify BIOS recognition in RetroArch settings
• Avoid HLE BIOS for full compatibility
• Dump BIOS legally from your own console

Additional Resources

• Libretro Documentation
• RetroArch Official Site
• MD5 Checksum Tool – WinMD5Free
• Sony Legal Terms