🔧 What’s a Custom ROM? A Beginner-Friendly Guide to Supercharging Your Budget Handheld (With love to the Anbernic RG35XX H, Miyoo Flip & friends)

Hey fam 👋

If you just grabbed yourself a budget-friendly retro handheld — like the Anbernic RG35XX H or the Miyoo Flip — first of all, congrats! You’re officially part of a whole new world of gaming ✨

But you might’ve heard whispers online about stuff like GarlicOS, OnionOS, or JelOS… and you might be wondering:

“What the heck is a custom ROM, and do I need one?”

Let’s break it down in plain English — and by the end of this guide, you’ll know what they are, which ones are worth trying, and how to install them — whether your handheld uses one SD card or two.

🧠 So… What Is a Custom ROM?

A custom ROM is basically a replacement operating system for your handheld. It’s like installing a better brain in your device — one made by the community, for gamers like you.

Most budget handhelds come with a default stock OS that’s... let’s be real: it works, but it’s kinda meh. The menus can feel clunky, game sorting is weird, and emulator settings might be buried or broken.

A custom ROM fixes all that.

🍭 Think of it like this:

• The stock OS is your high school cafeteria lunch — functional, but boring.

• A custom ROM? That’s your favorite home-cooked meal — delicious, tuned to your tastes, and full of extras.

🔥 Popular Custom ROMs (And Why People Love Them)

Here are some of the most popular ROMs out there for budget handhelds, and why they’re loved by the community:

🧄 GarlicOS (Anbernic RG35XX, RG35XX H, RG35XX Plus)

• Made for: Anbernic devices with dual SD card slots

• Why people love it:

  • Faster boot times

  • Clean and responsive UI

  • Per-system emulator settings

  • Great power management and sleep mode

• Perfect for: Folks who want an easy-to-use but powerful experience

🧅 OnionOS (Miyoo Mini / Mini Plus / Flip)

• Made for: Miyoo devices, especially the Flip and Mini Plus

• Why people love it:

  • Beautiful themes and animations

  • Save states and rewind features

  • Custom playlists and favorites

  • Actively developed by a tight-knit community

• Perfect for: Tinkerers and folks who love polish and flair

🪨 JelOS (Anbernic and other devices)

• Made for: Some Anbernic handhelds and other low-power Linux-based devices

• Why people love it:

  • RetroArch integration

  • Lightweight and fast

  • Built for emulation first

• Perfect for: Minimalists who want raw power without the frills

🧠 Bonus Tip: Not All Devices Support Custom ROMs (Yet)

Some newer handhelds may not have a custom ROM available right away — always check on forums like Reddit or GitHub to see what’s cooking 🔍

💽 Dual SD Card Setup: How to Install a Custom ROM (e.g. RG35XX H)

If your device has two SD card slots, here’s how it usually works:

🧰 What You’ll Need:

• A microSD card (preferably fast + name brand)

• A card reader for your PC/Mac

• A download of the custom ROM you want (from official GitHub pages)

• A backup of your original OS (just in case!)

🪛 Step-by-Step:

1. Download GarlicOS (or your ROM of choice)

   • Go to the GitHub page or trusted source

   • Download the latest version for your specific device

2. Format your SD card

   • Use Balena Etcher or a similar tool

   • Flash the ROM image to the first SD card (this is usually the "OS card")

3. Prepare your second SD card

   • This card holds your ROMs (games)

   • Format it as FAT32

   • Create folders like /GBA, /SNES, /PS1, etc.

   • Add your legally-dumped ROMs

4. Insert both cards, power on the device

   • First boot may take a minute, but you should see the new interface

   • Enjoy the glow-up ✨

💽 Single SD Card Setup: How to Install a Custom ROM (e.g. Miyoo Flip)

Some devices like the Miyoo Flip only have one SD card, so your games and OS share the same space. It’s just as easy — with one small twist.

🪛 Step-by-Step:

1. Download OnionOS

   • Find the correct version from the official GitHub

2. Backup your current SD card

   • Copy everything to a folder on your computer

3. Format the card (FAT32)

   • Clean slate! Make sure you backed up first

4. Copy OnionOS files onto the card

   • Usually involves dragging and dropping a few folders

5. Add your ROMs

   • Same as above: create folders like /GBC, /NES, etc.

6. Insert card, boot up, enjoy

   • You’ll get the OnionOS interface — smooth, customizable, and just plain better

🔄 Can I Go Back to the Stock OS?

Yes! Just re-flash your original backup onto your SD card. Nothing on your device is permanently changed, which makes custom ROMs fun and low-risk.

🎮 TL;DR: Why Custom ROMs Are Worth It

💡 Feature	Stock OS	Custom ROM
Fast boot time	❌	✅
Emulator tweaks	❌	✅
Save states / Rewind	❌	✅
Better UI	❌	✅
Themes & Skins	❌	✅
Game scraping / box art	❌	✅

🧳 Final Thoughts

Custom ROMs are one of the best parts of the retro handheld scene. They take your already-awesome device and level it up — smoother menus, better emulation, and more joy in every boot-up.

Whether you’re team Garlic, Onion, or JelOS, one thing’s for sure: once you install a custom ROM, you’re never going back 😎

Need help flashing? Want to share your setup? Hit the forums, I got you 👇

Until next time!

P’Nick ✨