GammaOS Next v1.0.0 (Anbernic T820) Release Notes

Patreon Exclusive Release
This build is currently available only to Patreon supporters. It will be made public after 60 days.
Password (release to public on 31st July 2025): ngfbs78b45tygh2jhsFGBFdbgdfgw3w434t42
Originally obtained from Patreon for Insider tier supporters: https://www.patreon.com/posts/exciting-gammaos-130439543

Release Date: June 1, 2025

Overview

GammaOS Next v1.0.0 marks the first official release for the Anbernic T820 family (RG556, RG-CUBE, RG406V, RG406H). Based on Android 13 / LineageOS 20, it offers a fully customized, performance-focused experience out of the box.

For the T820 release, please do not expect any raw performance improvements from stock firmware. This is a quality of life update.

Key Features

• Android 13 / LineageOS 20 Base
  A clean, debloated build for snappy performance and minimal bloat.

• Daijisho Launcher + RetroArch Integration
  Pre-configured for GB, GBC, GBA, NES, SNES, Genesis, PSX (BIOS files not included).

• Universal Button Remapping
  Map any physical button to any key or input—complete control over your gamepad layout.

• Analog Stick Calibration
  Adjust analog range and deadzone for more precise control.

• DC Dimming Emulation
  Reduces PWM flicker on displays that exhibit it—easier on the eyes during long play sessions.

• GammaRGB LED Sync
  Mirrors on-screen colors to supported RGB LEDs on analog sticks, and synchronizes LED brightness with the display.

• Deep Sleep Mode (cgroup Freeze)
  Force-freezes background apps to conserve power (use with caution—some apps may not resume properly).

• Screen Rotation Controls
  Enforce landscape mode when rotation is disabled to keep games and apps oriented correctly.

• App Drawer in Navigation Bar
  Quickly switch between any installed app without returning to home.

• Performance Governors & Modes

  • Max Performance: All frequencies at maximum for top speed.
  • Normal Performance: Dynamic scaling based on load.
  • Power Save: Lowered frequencies for extended battery life (ideal for light emulation).
    Toggle modes via Quick Settings.

• Quick Settings Tiles
  One-tap toggles for performance profiles, analog sensitivity, ABXY remapping, axis inversion, D-pad/analog swap, and more—no need for button combos.

• L2/R2 Button Fixes
  Ensures proper functionality in games and apps.

• Relaxed Scoped Storage
  Loosened file-access restrictions so apps can freely read/write without permission issues.

• Magisk Root
  Pre-installed root access with Magisk.

What’s Missing

• Finer RGB Control
  Current GammaRGB sync mirrors overall screen color, but per-LED granular control is not yet available.

• On-Screen Button Mapping
  No built-in touch-mapping utility. To map buttons on screen, install a third-party app such as Mantis Pro.

• Emulated Touchpad for External Displays
  Only screen mirroring mode is enabled. Emulated touchpad support when connected to an external monitor is planned but not available in this release.

• FM Radio
  Requires sources from the official firmware, which we'll never get.

Supported Devices

• Anbernic RG556
• Anbernic RG-CUBE
• Anbernic RG406V
• Anbernic RG406H

Flashing Requirements

• Windows Only (Current Release)
  The firmware archive is flashable via Windows only. Future releases will include support for Linux/macOS using the spd_dump tool: spreadtrum_flash

• Split Archive
  Each build is split into three parts for extraction via 7-Zip. Example naming for RG406H:

  • RG_406H_GammaOS_Next_Full_v1.7z.001
  • RG_406H_GammaOS_Next_Full_v1.7z.002
  • RG_406H_GammaOS_Next_Full_v1.7z.003

Installation

1. Download the v1.0.0 firmware package from GammaOS Next Releases.
2. Use 7-Zip on Windows to extract all three .7z.00x parts into one folder.
3. Follow the Installation Guide for detailed flashing instructions (brand-new install or upgrade).

RECOMMENDED

Install GammaPad patch for improved vibration support and system stability (if you get crashes to Boot logo during force feedback events): #29

Known Issues

• Some third-party apps may not fully resume when using Deep Sleep Mode.
• DC Dimming emulation may slightly alter color accuracy on certain panels.
• HDMI audio does not play, audio currently goes through the device speakers.

For any questions or troubleshooting, please visit our GitHub Issues page.

Enjoy GammaOS Next on your Anbernic T820 device!

Stock firmware package, flashed using the same tool as GammaOS:

RG 556: https://drive.google.com/file/d/1hYuUPBTHAghZXXVt5urnAhJP-_vofg3K/view?usp=sharing
RG Cube: https://drive.google.com/file/d/1DBl9ZwvyqUdjMmetA2ekYWKS1uUcmI0b/view?usp=sharing
RG 406v: https://drive.google.com/file/d/10ivdlP5CsVInWOa66RpjjCxLI38Lo1-2/view?usp=sharing
RG 406h: https://drive.google.com/file/d/1UVdcEFBBagm4Dmj28w8tyiQuGFyVhXAk/view?usp=sharing

To fix OTAs after flashing stock again:
TheGammaSqueeze/Bootloader_Unlock_Anbernic_T820@e5f7dfc