PS1 BIOS Files: Which Ones You Need for DuckStation and RetroArch

Last updated: September 2026

A PS1 emulator with no BIOS gives you a black screen and nothing else. Not a warning, not a menu, just black. I have watched more people bounce off PS1 emulation at that exact moment than at any other step, and the fix takes two minutes once you know which file goes where.

This page is the PS1 half of my RetroArch BIOS guide, expanded to cover DuckStation, the RetroArch PS1 cores, and the Linux and Android handhelds most of you are actually running. Filenames, hashes, folder paths per platform, and the legal way to get the files. No download links, and I explain why at the end.

The Three PS1 BIOS Files That Matter

The PlayStation shipped with a dozen BIOS revisions across its life, but modern emulators standardise on the SCPH-5500 series. One per region, and each region’s file has one correct MD5 hash.

Grab the one matching the games you play. If you play imports, keep all three. DuckStation and the Beetle PSX core both pick the right region automatically when all three sit in the folder.

Other revisions you will see mentioned

My rule: if the emulator has a preferred set, use the 5500 series and stop thinking about it. The only time I reach for something else is psxonpsp660.bin on a PSP-derived setup, because it boots faster and covers every region in one file.

Where Each Emulator Looks

This is the part people get wrong. Every emulator has its own folder, none of them search subfolders, and Linux is case-sensitive.

DuckStation (Windows, Mac, Linux, Android)

DuckStation keeps a bios folder inside its data directory:

Drop the .bin files straight in. Then open Settings > BIOS and you will see each region slot resolve to a named file. If a slot still says “auto-detect” with nothing found, the file is either in a subfolder or the hash is wrong.

DuckStation also accepts a PS2 BIOS dump, because the PS2 firmware contains the PS1 boot ROM. If you already dumped a PS2 for PCSX2 or NetherSX2, you can point DuckStation at that file and skip a separate PS1 dump.

RetroArch (Beetle PSX, PCSX ReARMed, SwanStation)

All three cores read from the system directory, the same folder every other core’s BIOS lives in:

Confirm the path in Settings > Directory > System/BIOS. Then load the core and check Information > Core Information from the Quick Menu. Each BIOS line shows “Present” or “Missing” with the expected hash, which makes this the easiest verification screen in the whole hobby.

Beetle PSX refuses to run without a matching region file. PCSX ReARMed has a built-in HLE BIOS that boots most games without one, but compatibility drops and a handful of titles hang at the memory card check. Put the real file in and forget the HLE fallback exists.

Linux handhelds (muOS, Knulli, ROCKNIX, OnionOS, GarlicOS)

The custom firmware crowd each picked a folder:

Filenames stay exactly as in the table above. Every one of these firmwares runs RetroArch cores underneath, so the core’s expectations are what count.

Android handhelds

Standalone DuckStation on Android is the best PS1 experience on a Retroid or Anbernic Android device, and it asks you to choose a BIOS folder on first launch. I make a folder called Emulation/bios on the SD card, put every BIOS I own in it, and point DuckStation, NetherSX2 and RetroArch at the same place.

How to Verify a BIOS File

Wrong file, black screen. Always hash your dumps.

Windows PowerShell:

Get-FileHash .\scph5501.bin -Algorithm MD5

Linux and macOS:

md5sum scph5501.bin

Compare against the table. Two other quick checks: every PS1 BIOS is exactly 524,288 bytes (512 KB), and the file must end in .bin with no double extension. Windows hides extensions by default, so scph5501.bin.bin is a real thing I have fixed on other people’s machines more than once.

How to Dump the BIOS From Your Own PlayStation

The preservation-correct way to get these files is from hardware you own. Three routes, in order of how much I like them:

1. FreePSXBoot. A memory card exploit that runs unsigned code on an unmodified PS1. You write the exploit to a memory card using a PS2 with FreeMcBoot or a PC memory card adapter, boot the PS1 with it inserted, and run a BIOS dumper that writes the file back to the card. No soldering, no modchip. The project lives on GitHub.
2. Modchipped console. If your PS1 already has a chip, burn a BIOS dumper disc and run it. Same output.
3. From a PS2. Every PS2 contains the PS1 BIOS. If you dump the PS2 with biosdrain (covered in my PS2 BIOS guide), DuckStation reads the PS1 portion directly. For RetroArch you still need the standalone scph*.bin files.

The PSP route (psxonpsp660.bin) comes from a PSP running custom firmware. It is a single region-free file, and DuckStation lists it as supported.

Common Problems

Black screen, no sound. No BIOS found. Check the folder path in the emulator’s settings, then check for subfolders and double extensions.

Boots to the PlayStation logo, then hangs. Usually a region mismatch with a core that cannot auto-switch, or a corrupt dump. Hash the file.

Games run but memory cards never save. PCSX ReARMed in HLE mode. Install the real BIOS.

DuckStation says “BIOS image is not a known good dump.” It runs anyway. The hash does not match its database, which happens with rarer revisions. If games work, ignore it. If they do not, get one of the 5500 series.

Fast boot skips the logo, and one game breaks. A few titles depend on the BIOS boot sequence. Turn fast boot off for that game in its per-game settings.

Why I Do Not Link to Downloads

BIOS files are Sony’s copyrighted firmware. Emulators are legal, and dumping the firmware from a console you own is the defensible position. The sites that host “PS1 BIOS packs” are the same sites that stuff installers with adware, and I have no way to vouch for what is in their zip files. Dump your own, hash it, and you are done for life.

FAQ

Which PS1 BIOS is best?

scph5501.bin for North American games, scph5502.bin for PAL, scph5500.bin for Japanese. Together they cover everything, and DuckStation and Beetle PSX both auto-select by game region.

Does DuckStation need a BIOS?

Yes. DuckStation has no HLE BIOS. It will not start a game without a real file.

Can I use the same BIOS for RetroArch and DuckStation?

Yes. Same files, different folders. Copy them to both locations.

Is scph1001.bin the same as scph5501.bin?

No. Both are North American, but they are different revisions with different hashes. Both work in DuckStation; Beetle PSX in RetroArch specifically wants 5501.

Do I need a BIOS for PS1 on the Miyoo Mini Plus or RG35XX?

Yes. Stock firmware, OnionOS, muOS and GarlicOS all run PCSX ReARMed or a similar core and expect the file in the BIOS folder listed above.

DuckStation | Beetle PSX core docs | FreePSXBoot

Last verified: September 2026