Put the Saturn BIOS in the folder shown in RetroArch under Settings > Directory > System/BIOS, then use the filename and any subfolder required by your selected Saturn core. There is no single Saturn BIOS filename or path that works for every core: for example, Kronos expects kronos/saturn_bios.bin inside the system directory, while Beetle Saturn uses region-specific filenames.
Find RetroArch’s System/BIOS directory
- Open RetroArch and go to Settings > Directory > System/BIOS.
- Note the directory path displayed there. This is the system folder RetroArch is configured to use; it may differ from a path in an installation guide or on another device.
- Check which Saturn core you will launch. Use that core’s documented filename and folder structure before copying or renaming any BIOS file.
Libretro’s BIOS Information Hub advises checking the core documentation for the specific location and notes that capitalization can matter on case-sensitive operating systems.
Use the filename required by your Saturn core
| Core | Documented BIOS filename and location | Requirement and notes |
|---|---|---|
| Beetle Saturn | sega_101.bin for Japanese games; mpr-17933.bin for US/European games, in RetroArch’s configured system directory. |
The Beetle Saturn documentation lists the BIOS for the corresponding game regions and publishes MD5 values. |
| Kronos | SYSTEM_DIRECTORY/kronos/saturn_bios.bin |
The Kronos documentation requires a Saturn BIOS for Saturn games. It says the published MD5 is a hint and that any valid Saturn BIOS should work. If the expected path is not found, Kronos may check common locations used by other Saturn cores. |
| Yabause | saturn_bios.bin in RetroArch’s configured system directory. |
The Yabause documentation lists the BIOS as optional, recommends a real BIOS for compatibility, and says it is required for its multi-disc M3U workflow. |
| YabaSanshiro | saturn_bios.bin in RetroArch’s configured system directory. |
The YabaSanshiro documentation lists the BIOS as optional. It describes the core as outdated, known to have issues, and unmaintained, and recommends another Saturn core where possible. |
For Kronos, if RetroArch’s system directory is /path/to/system, the documented location is /path/to/system/kronos/saturn_bios.bin. Create the kronos subfolder if needed. Do not put the file in that subfolder when using a core that expects it directly in the system directory.
Check the BIOS if the core does not detect it
- Confirm the configured path: return to Settings > Directory > System/BIOS and make sure the file is in that directory, or in the required subfolder.
- Check the exact name and extension: match spelling and capitalization, including
.bin. Some operating systems distinguish uppercase and lowercase names. - Confirm the active core and game region: Beetle Saturn documents different BIOS filenames for Japanese versus US/European games. Other cores have different naming requirements.
- Compare the file’s MD5 when applicable: Beetle Saturn lists
sega_101.binas85ec9ca47d8f6807718151cbcca8b964andmpr-17933.binas3240872c70984b6cbfda1586cab68dbe. Kronos listssaturn_bios.binasaf5828fdff51384f99b3c4926be27762, but calls that value a hint rather than a strict requirement. Do not use one core’s filename or hash as the rule for another. - Check read access: if the path and filename are correct but the core still cannot use the file, verify that RetroArch can read the folder and file. This is a practical permissions check, not a core-specific BIOS rule.
After correcting the path or filename, relaunch the core and test a game. Restarting may be worth trying, but the core documentation does not establish one universal restart procedure or guarantee that restarting alone will resolve detection.
#1 Best Overall
- OFFICIALLY LICENSED BY SEGA – Manufactured under official Sega license for authentic design, premium quality, and faithful performance inspired by the original Sega Saturn controller.
- WIDE DEVICE COMPATIBILITY – Works with Sega Genesis Mini, Nintendo Switch, PC, Mac, Steam, RetroPie, Raspberry Pi, and more for plug-and-play retro gaming.
- SWITCH BETWEEN X-INPUT & D-INPUT – Easily toggle input modes by holding the START button for 5 seconds, ensuring compatibility with modern games and emulators.
- EXTRA-LONG 10 FT CABLE – Enjoy comfortable gaming from your couch with a durable 10-foot USB cable that gives you more freedom to play.
- BUILT FOR RETRO GAMERS – Original-grade build quality with comfortable ergonomics, responsive controls, and the authentic six-button layout trusted by Sega fans.
BIOS files and game content
Libretro’s BIOS guide says RetroArch and Libretro do not provide copyrighted system files or game content; users must supply their own BIOS and content in accordance with applicable local laws.
Quick Recap
Best Value
- Official SEGA Licensed Controller (Original Grade Quality)
- Classic 6-Button Layout
- Compatible with Sega Genesis Mini, Nintendo Switch, PC, Mac, Steam, RetroPie, Raspberry Pi
- For USB, swap between D-Input and X-Input by holding the START button for 5 seconds
Rank #4
- MULTI-COMPATABILITY: Includes SEGA Saturn and USB wireless receivers. Compatible with SEGA Saturn consoles via console receiver. Compatible with PC, Mac, Switch, and other USB-enabled devices via USB receiver
- PRECISION CONTROLS: Features dual Hall Effect analog sticks for durability and precision. 3D Control Pad support* enabled by macro via console receiver
- MULTIPLE FUNCTIONS & FEATURES: Dual analog rumble motors** incorporated in the controller. Four shoulder buttons, Home, and Select buttons.
- RECHARGEABLE: Built-In 500 mAh battery with USB-C fast charging port (3ft/1m USB-C to USB charge cable included)
- FIRMWARE UPDATE: Day 1 firmware update is available for this product. Please update before use! Instructions for firmware can be found on the Retro-Bit website under Support.
Rank #3
- Compatible with PC, MAC, STEAM, Super Retro Cade
- 3m cord length
- 5mm cord thickness
- Original Grade Quality
- Color originally only available in Japan;Officially licensed by SEGA
Rank #2
- 6 ft. Cable
- Features classic d-pad, 2 shoulder buttons, and 6 face buttons
- Compatible with PC/Mac via USB
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