Guides

Firmware

Custom OS deep-dives and comparisons — muOS, Knulli, Onion OS, and more.

13 guides

iiSU Setup Guide: The New Visuals-First Android Frontend — Firmware guide for retro handhelds | Held Games
Guide
iiSU Setup Guide: The New Visuals-First Android Frontend
iiSU is a visuals-first Android launcher for handhelds, with a PSP and 3DS feel, a WiiSU menu mode, and RetroAchievements. Here is how to set it up.
2026-06-17
AmberELEC Setup Guide for RK3326 and RK3566 Handhelds — Firmware guide for retro handhelds | Held Games
Guide
AmberELEC Setup Guide for RK3326 and RK3566 Handhelds
How to install AmberELEC, the feature-rich EmulationStation firmware for RK3326 and RK3566 handhelds like the Anbernic RG351 and RG353. Flashing, WiFi, and games.
2026-06-04
ArkOS Setup Guide for Anbernic and Powkiddy RK3326/RK3566 Handhelds — Firmware guide for retro handhelds | Held Games
Guide
ArkOS Setup Guide for Anbernic and Powkiddy RK3326/RK3566 Handhelds
How to install and set up ArkOS custom firmware on RK3326 and RK3566 handhelds like the RG351 and RGB10. SD cards, WiFi, and emulators covered.
2026-06-04
Batocera Setup Guide: The All-in-One Emulation OS for Handhelds — Firmware guide for retro handhelds | Held Games
Guide
Batocera Setup Guide: The All-in-One Emulation OS for Handhelds
How to set up Batocera, the all-in-one Linux emulation OS that runs on handhelds, PCs, and single-board computers. Flashing, WiFi, scraping, and adding games.
2026-06-04
CrossMix OS Setup Guide for the Trimui Smart Pro and Brick — Firmware guide for retro handhelds | Held Games
Guide
CrossMix OS Setup Guide for the Trimui Smart Pro and Brick
How to install CrossMix OS, the feature-rich custom firmware for the Trimui Smart Pro and Brick. A polished, all-in-one setup with great emulator support and tools.
2026-06-04
NextUI and MinUI Setup Guide: A Minimal Frontend for Trimui and Miyoo — Firmware guide for retro handhelds | Held Games
Guide
NextUI and MinUI Setup Guide: A Minimal Frontend for Trimui and Miyoo
How to set up NextUI and MinUI, the minimal pick-up-and-play frontends for the Trimui Brick, Miyoo Mini, and more. Clean menus, fast boot, and long battery life.
2026-06-04
Spruce Setup Guide: Custom Firmware for the Miyoo Mini Plus — Firmware guide for retro handhelds | Held Games
Guide
Spruce Setup Guide: Custom Firmware for the Miyoo Mini Plus
How to install Spruce, the popular custom firmware for the Miyoo Mini Plus. A polished, feature-rich alternative to Onion OS with a clean look and handy tools.
2026-06-04
GammaOS Setup Guide for Anbernic Android Handhelds — Firmware guide for retro handhelds | Held Games
Guide
GammaOS Setup Guide for Anbernic Android Handhelds
How to install and configure GammaOS on your Anbernic Android handheld. Get a gaming-focused launcher, better controls, and tuned emulator settings.
2026-04-10
muOS vs KNULLI vs Onion OS: Which Custom Firmware Should You Use? — Firmware guide for retro handhelds | Held Games
Guide
muOS vs KNULLI vs Onion OS: Which Custom Firmware Should You Use?
A head-to-head of the three most popular handheld firmwares. muOS, KNULLI, and Onion OS compared on features, performance, ease, and device support.
2026-04-09
How to Install KNULLI on Your Anbernic Handheld — Firmware guide for retro handhelds | Held Games
Guide
How to Install KNULLI on Your Anbernic Handheld
Flash KNULLI custom firmware on your Anbernic handheld — a step-by-step guide from a blank microSD card to a fully configured retro gaming machine.
2026-04-04
muOS Setup Guide: Anbernic RG35XX, RG40XX, and RG28XX — Firmware guide for retro handhelds | Held Games
Guide
muOS Setup Guide: Anbernic RG35XX, RG40XX, and RG28XX
Flash muOS on your Anbernic RG35XX Plus, RG40XX H, or RG40XX V — a lean RetroArch-first launcher with fast boot times, PortMaster, and minimal overhead.
2026-04-02
KNULLI Setup Guide: Anbernic RG35XX, RG40XX, and RG28XX — Firmware guide for retro handhelds | Held Games
Guide
KNULLI Setup Guide: Anbernic RG35XX, RG40XX, and RG28XX
Flash KNULLI on your Anbernic RG35XX Plus, RG40XX H, or RG40XX V — EmulationStation frontend, per-game settings, WiFi file transfer, and PortMaster included.
2026-03-29
How to Set Up Onion OS on the Miyoo Mini Plus — Firmware guide for retro handhelds | Held Games
Guide
How to Set Up Onion OS on the Miyoo Mini Plus
The complete beginner's guide to transforming your Miyoo Mini Plus into the ultimate retro machine using Onion OS.
2024-03-19