This release of UnofficialOS brings new and updated cores and emulators, support for the Anbernic RG ARC S/D, R36T and R36T Max. The RG ARC-D is confirmed working with android (stock/GammaOS Core) on the emmc. BigPEmu has been added to all units, as a stand alone Atari Jaguar emulator. PortMaster has been updated to the latest beta since it contains uOS specific fixes. Special thanks to @christianhaitian and @ROCKNIX for the BigPEmu references, @kloptops for the speedy merge of my PortMaster commits, and @KitFox618 for the help testing.

New Device Support

• Anbernic RG ARC-S/D
• AISLPC R35T/R36T Max - overlays

New Cores and Emulators

• gearlynx - Atari Lynx
• geargrafx - PC Engine/CD, TurboGrafx-16/CD, Super Grafx
• geolith - Now Supports Neo Geo CD
• BigPEmu v1221 - Atari Jaguar

Updated Cores and Emus

• PortMaster - 2026.05.04-1202
• PCSX2 - v2.7.321
• Vita3K - 3969 - Instructions
• RPCS3 - 0.0.40-19335 - Instructions

Fixes

• Fix Dolphin Rotaion - X55
• Fix Filemanager - X55
• RG ARC Retroarch/SA controls and remaps
• Device Specific Quirks for BigPEmu Config Files

Installation

Fresh Install

1. Download the proper *.img.gz for your device.
2. Extract the .img and flash the image to your microSD card using your favorite image writing tool (Balena Etcher, Raspberry Pi Imager, Win32 Disk Imager, dd etc.)

Installation Image Downloads

Upgrading Over the Air (OTA)

If your device has access to the internet you can update UnofficialOS directly from EmulationStation.

1. In EmulationStation open the main menu by pressing the "Start" button on your controller.
2. Select System Settings
3. Scroll to the System Update header and select Start Update

Upgrading Manually

If you device does not have access to the internet you can still update manually

1. Download the latest update (.tar) of UnofficialOS for your device from below or the releases page.
   • Make sure to download the correct .tar file for your device. For example; if you are installing UnofficialOS on a RG351P you would download the UnofficialOS-RK3326 file.
   • If you have any questions you can check the Device Support section to confirm which .tar you should download for your specific device.
2. Copy the update to your device's update share.
   • via SCP to /storage/.update
   • via Samba to "update"
3. Reboot the device, and the update will begin automatically.

Update Package Downloads

IMPORTANT Known Bugs/Issues

Clones Units

Currently some clone units currently have no LEDs working when uOS is running.

Powkiddy X55

This device has a few known issues.

1. Charge the unit while its turned on, not while its powered off or sleeping.
2. Plugging the power cable in with the unit off causes it to boot. This is normal right now for the unit to charge.
3. Powering down fully for more then a few minutes at a time resets the battery meter. This IS NOT drain, its a bad meter reading.
4. And last, sleeping the unit breaks sound.

What I have been doing currently is charging the unit to 100%, sleeping the unit when not in use, then I'll wake it and reboot when I want to use it. It still has very good battery life when sleeping, as I only lose between 5% and 10% battery daily. Not ideal I know, I'm working towards a fix.

Odroid Go Advance

There is currently hotkey issues with this unit, specifically with PortMaster. Ports require a hard shutdown (not recommended).

Working on fixes for all mentioned issues and bugs. Please report bugs/issues to the uOS discord here.

Changelog

The commits and changes can be viewed here in the pull request for this release.

Donate

Love this project? Please consider supporting us on Ko-Fi