Gamma released the beta version of GammaOS Core in early September. It supports a variety of low-powered consoles, bringing Android to devices once only able to run Linux.

Table of Contents

• Introduction
• What You’ll Need
• GammaOS Core Install Guide
  • Step 1: Set Up
  • Step 2: Create the GammaOS Core Card
  • Step 3: Install GammaOS Core
  • Step 4: Post-Install
• Wrap-Up

Introduction

Android on various retro handhelds can sometimes mean more options for emulators, potentially leading to more support and updates as the years pass. Oftentimes, it opens the floodgates into a sea of possible hacks, tweaks, and mods gamers can use to, for example, automatically sync cloud saves, or connect directly to network storage.

GammaOS brings those possibilities to numerous Anbernic and Powkiddy devices:

• Powkiddy RGB30
• Powkiddy RGB20SX
• Powkiddy RGB10Max 3
• Anbernic RG503
• Anbernic RG353M
• Anbernic RG Arc-D
• Anbernic RG Arc-S
• Anbernic RG353V
• Anbernic RG353VS
• Anbernic RG353P
• Anbernic RG353PS

If you prefer a video guide and a quick overlook of the features, you can watch Derek’s video on the Retro Handhelds YouTube page.

What You’ll Need

• One of the devices mentioned above
• Windows PC
• 7-Zip
• GammaOS Core
  • available on Gamma’s Github
• Rockchip SD Disk Tool
• 32GB or higher MicroSD card

GammaOS works best with SD cards above 32GB, but I’ve had success using a variety of 16GB cards as well – but we would still recommend 32GB or higher.

On the GammaOS Github, each download has a device name in its title. For me, using an RGB30, I would naturally need the “GammaOS_Core_Beta1_RGB30_RGB20SX.7z” file. Download the one for your device, not any other. GammaOS is made specifically for these devices, so using a different one will simply not work or not work as optimally as it should.

GammaOS Core Install Guide

It should be noted that installing GammaOS Core in its current beta state may give you more bugs than when the official release drops. The process should be the same, download names may be slightly different, but this guide should be useful to anyone looking to put Core on one of the aforementioned devices.

Step 1: Set Up

When downloading 7-zip, you want to ensure that you are downloading the right one for your computer. Most people will be able to use the 64-bit option, the first one on the list. If you’re unsure, you can check in your Settings app, then About at the bottom. x32 needs the 32-bit version, x64 needs the 64-bit one, and an ARM-based computer needs the arm64 one.

Once it’s downloaded, double-click the .exe and follow the installation prompts.

After downloading GammaOS Core and the Rockchip SD DIsk Tool, you’ll be left with a .7z file for GammaOS and a .zip for the Disk Tool. Double-click them both, separately, and 7-Zip should open a window displaying all of the contents of the .7z file. The .zip file for the SD Disk Tool should open similarly to the Windows Explorer screenshot below, but it may have the shown files inside of a folder also named the same as the .zip file.

The .7z file should contain a single .img file, and the .zip should contain eight files, one of them being a .exe file.

Once you’ve double-clicked the GammaOS .7z file, and it has opened 7-zip, hit Extract in the upper lefthand corner as shown below. Then, on the following screen, hit Ok. This will place the .img file inside a folder with the same name as the .7z file.

Extracting the GammaOS image

After double-clicking the Disk Tool .zip file, it should open and look similar to the screenshot below. If you’ve set 7-zip to handle zip files, then it will be a screen that looks reminiscent of the one above. If not, don’t worry — it doesn’t matter. Just follow the same extraction steps you’ve followed for the .7z file above.

SD Disk Tool extraction

Hit Extract All in the options ribbon, and Extract on the following screen. This will also place the Disk Tool and its seven included files in a folder with the same name as the zip.

Step 2: Create the GammaOS Core Card

WARNING: Officially, Gamma recommends using the SD Disk Tool that you’ve downloaded above. However, we’ve seen reports of people using Rufus and finding success.

Open the folder with the Disk Tool within it and double-click the SD_Firmware_Tool application. You may be presented with a prompt saying “Windows has protected your PC” but we’re going to ignore that. Hit More info, and then Run anyway. If you see a prompt after this with a yellow banner at the top, just hit Yes.

In the dropdown for the first option, where it says Choose removable disk, you should select your MicroSD card. If it shows two options with the same name, choose the one with a listed storage size.

The second option Choose function mode be sure to tick SD Boot.

For the third option, Choose firmware, and find the .img file that should be inside the GammaOS folder you created earlier when extracting the .7z file.

Your screen should look almost exactly like the one below.

How your SD DIsk Tool should look

Finally, hit Create. This process will flash the image to your SD card, but not via normal means. It may take a few minutes, but it shouldn’t be that bad. On a 16GB card, it took about ten minutes on an old Intel i5 Mac mini running Windows. A 400GB card took a few hours.

You’ll know it’s done once you get a prompt saying Creating upgrade disk ok.

If you see this screen, you’re doing great.

Step 3: Install GammaOS Core

Your SD card has been flashed and now you’re off to the races. Pop the SD card out of your computer, and put it in your device’s TF1 slot, or, if your device only has one SD card, the single SD card slot.

Power on your device, and the installation will commence. One of the first things you’ll see is four Linux penguins followed by a black screen. The installation may take a long time, but after a while, you should see the GammaOS logo, and finally, the Android setup screen.

The illustrious GammaOS Welcome Screen

Step 4: Post-Install

GammaOS Core is installed preconfigured for the device it is made for. Meaning, the settings within apps, where they look for games, all of it. It comes with Daijisho or PlainLauncher, but I’ve only had decent success with the former.

If your games aren’t being found via Daijisho, highlight the console you’re having problems with and hit the Paths button at the bottom. Then hit Add More on the following screen. From here, browse through the file manager until you find the folder with all of that console’s games. Once you’re inside the folder, tap the blue Use This Folder at the bottom, followed by Allow. If your file manager says Allow Access instead of Use This Folder, tap it and do the same thing.

Once you do that, you should see the folder path right in the middle of your screen. Hit Sync. This will begin an automatic process to add the games to your library.

GammaOS comes preinstalled with RetroArch and Daijisho will default to using it. You can adjust the cores being used by going to a specific console and entering its settings from within Daijishjo. It should be noted that GammaOS Core is a beta itself, but more so, Android technically isn’t supposed to run on a device with this little processing power. How well a game will work with a specific core under these conditions will require a lot of testing from various parts of the community.

If you prefer to use other emulators or want to download apps, you can use the included Aurora Store. It’s an alternative to the Google Play Store that allows you to anonymously (no account needed) download apps.

It looks similar to the Google Play Store that you may frequently see on your phone, but it’s… not.

Aurora Store

Alternatively, you can download APK files on your computer, turn off and remove the SD card from your device, put it in the computer, and finally move the .apk to a memorable location. Pop the card back in, open the File Manager, find the .apk, and install it by opening them.

If you get a warning saying you can’t install apps from this source, hit the shown Settings button, then turn the Allow from this source knob to on. Afterward, Android will ask if you want to install it, go ahead and hit Yes.

Wrap-Up

GammaOS is one of my favorite projects in the retro handheld space. For the past three or four decades, software modders and developers have been installing Doom on various different electronics; fridges, microwaves, electronic pregnancy tests, everything. It’s exciting to see, now, that the same spirit lives on but in much more practical ways.

Installing Android can be a game changer for some people. Some people enjoy that it runs a similar OS to their phones, but some people don’t. Thankfully, due to Gamma’s continued development and support, people now have the choice.

What did you think of this guide? Will you be checking out GammaOS Core on your RK3522 device? Let us know in the comments below, and chat with us in our Discord!

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