Download PS1 BIOS for ARMSX1

The PS1 BIOS is an essential component of the ARMSX1 emulator. It serves as the core system for running PlayStation 1 game discs within the ARMSX1 emulator. The emulator replicates the hardware of the PlayStation 1 console and then executes the BIOS, just as it would on the original console.

You must provide the BIOS yourself by downloading it from this site if you wish to play PS1 games on an emulator such as ARMSX1. The BIOS handles various functions, including controller input, memory card management, game disc execution, and more. PS1 BIOS files are very small—approximately 512 KB each—so they will not take up much storage space, even if you download every available version.

Download All BIOS Versions

Below are all the PS1 BIOS versions that we have tested on ARMSX1, all of which work perfectly. Please ensure you select the appropriate BIOS version for the game you intend to play.

Region Console model Download Video
USA SCPH-1001 NTSC-U
USA SCPH-7003 NTSC-U
Europe SCPH-7502 PAL
Japan SCPH-5500 NTSC-J

Within a given region, use the latest BIOS version (for example, SCPH-7003 rather than an older version like SCPH-1001) to ensure a better gaming experience. Selecting the appropriate BIOS version can also be important; for instance, games originating from Japan may run better when using the SCPH-5500 BIOS.

How to Add a BIOS to ARMSX1

  1. Save the BIOS file in one folder

    Download the BIOS from the table above, then put the BIOS file in one folder, for example Download/armsx1.

  2. Open ARMSX1 initial setup

    When first opened, ARMSX1 displays a three-step setup: App Data Folder, BIOS Location, and ROM Location. Tap Next, choose where to save the memory card, save state and configuration, then tap Next again.

    ARMSX1 setup welcome screen listing three steps: App Data Folder, BIOS Location and ROM Location, with the Next button
    Tap Next to start setup.
    ARMSX1 App Data Folder options: Internal, SD Card and Custom folder, with Internal selected
    Select the location of the app data, then tap Next.

  3. Select BIOS folder

    On the Select your BIOS screen, tap Select BIOS. Open the folder from step 1, tap Use this folder, then Allow. ARMSX1 scans that folder and displays all detected BIOSes and their region flags. Select one (marked BIOS selected), then tap Next. This selection can be changed at any time in the BIOS settings. If the list is empty, tap Pick a different folder and check that the BIOS file is already in that folder, is not in a ZIP, and is 512KB in size.

    Select your BIOS screen in ARMSX1 with the Select BIOS button for picking a folder of PS1 BIOS files
    Tap Select BIOS.
    Android folder picker open at Download/armsx1 with four PS1 BIOS files from armsx1.com, with the Use this folder button
    Open the BIOS folder, then tap Use this folder.
    Dialog asking to allow ARMSX1 to access files in armsx1, with the Cancel and Allow buttons
    Tap Allow.
    4 BIOS files ready in ARMSX1: SCPH-1001 and SCPH-7003 (USA), SCPH-5500 (Japan), SCPH-7502 (Europe), with SCPH-1001 marked BIOS selected
    All four BIOSes are detected. Select one, then tap Next.

  4. Add game folder

    On the Select ROMs folder screen, tap Pick ROMs Folder, navigate to the folder where you keep your PS1 games, then tap Use this folder and Allow. The folder will be added to the list. Tap Add Another Folder if your games are stored in several different folders, then tap Next.

    Select ROMs folder screen in ARMSX1 with the Pick ROMs Folder button
    Tap Pick ROMs Folder.
    Android folder picker showing a PS1 game folder with BIN and CUE files, with the Use this folder button
    Select the game folder, then tap Use this folder.
    Dialog asking to allow ARMSX1 to access files in the game folder, with the Allow button
    Tap Allow.
    Download/armsx1 added to the ARMSX1 ROMs folder list, with the Remove, Add Another Folder and Next buttons
    The game folder has been added to the list. Tap Next.

  5. Apply setup

    The Apply & Finish screen summarizes your selections: the App Data Folder, the BIOS version under BIOS Location, and the number of folders under ROM Location. Tap Let's Go.

    ARMSX1 Apply & Finish summary: App Data Folder Internal, BIOS Location v2.20, ROM Location 1, with the Let's Go button
    Review the summary, then tap Let's Go.

  6. Play the game

    ARMSX1 scans your game folders, and any detected games will appear in your library, complete with their cover art. Tap on a cover to launch the game using your chosen BIOS.

    ARMSX1 library showing the Crash Bandicoot: Warped cover after the game folder is scanned
    The game appears in your library. Tap to play.

PS1 BIOS Features on ARMSX1

Here is what ARMSX1 does with your BIOS files—from scanning folders to selecting the appropriate BIOS for a specific game.

Detected from Its Content

ARMSX1 calculates the MD5 checksum of each 512 KB file and compares it against a list of BIOS files recognized by the application. The filename does not matter, so there is no need to rename your files to anything specific.

Region and Version Displayed

Each detected BIOS will be displayed with a region flag, the console model, and its version—for example, SCPH-5500 (v3.0 09-09-96 J).

Multiple BIOS at Once

All BIOS files in the folder you select will be added to the list. Choose one BIOS for the emulator to use; you can change the BIOS in the settings whenever you like. Use Import BIOS file… to add more BIOS files without changing the folder.

Select Primary BIOS

You can specify which BIOS to use first via the Preferred console model setting. If that BIOS is not detected, ARMSX1 will automatically use another available BIOS. Changes will take effect when the game is restarted.

Per Game Custom BIOS

A BIOS can be set for specific games only, while other games can continue to use the global BIOS.

OpenBIOS Detected

OpenBIOS is a community-developed, open-source alternative to a BIOS. ARMSX1 can detect it as a valid BIOS. Many games can run using this BIOS, though not all of them.

Download ArmSX1 Full install guide

Frequently Asked Questions

Since the BIOS is proprietary firmware owned by Sony and not part of ARMSX1, you'll need to add the BIOS file yourself, either from your console or from this page.

Adjust to the region of the game you're playing. This page provides SCPH-1001 and SCPH-7003 for USA games, SCPH-7502 for European (PAL) games, and SCPH-5500 for Japanese games. You can download all three regions; ARMSX1 has an automatic system that can select the appropriate BIOS for each game.

No. ARMSX1 can detect the BIOS by its checksum, not by its name, so scph5501.bin and bios.bin are considered the same if their checksums are identical. The file size must also be exactly 512 KB; otherwise, it will be ignored.

The folder you selected does not contain a detected BIOS file. Most often, the BIOS file has not been moved to the folder you added in ARMSX1.

Yes. You can set a BIOS for one game only, while other games keep using the global BIOS.

ARMSX1 can detect OpenBIOS, the open-source PS1 BIOS replacement, as a valid BIOS. OpenBIOS is neither a Sony code dump nor a perfect replacement: some games rely on BIOS behavior that OpenBIOS may not handle.