The TrimUI Brick is one of those rare budget handhelds that genuinely earns its hype, but the trimui brick setup process has a handful of landmines that catch almost every new owner off guard. A corrupted SD card on day one, BIOS files dropped into the wrong folder, ROMs that refuse to show up in the menu, a device that seemingly shuts itself off for no reason. These are not hardware defects. They are setup errors, and every single one is avoidable.
This guide walks through the entire pipeline from unboxing to fully loaded library. It covers SD card selection and formatting, firmware options, the exact BIOS directory structure MinUI expects, ROM folder naming conventions, wireless transfer via Syncthing, PortMaster pitfalls, and the hardware quirks that will confuse you if nobody warns you about them. No fluff. Just the steps that actually work.
KEY TAKEAWAYS
- FAT32 is mandatory for SD card stability. Use Rufus for any card over 32GB. exFAT may appear to work, but it is far more likely to corrupt files over time.
- MinUI and NextUI are the two best custom firmware options for the TrimUI Brick right now. CrossMix OS is still developing for this device.
- BIOS files in MinUI go into system-specific subfolders such as
/Bios/GBA/and/Bios/PS/. File names and folder names need to match exactly.- ROM folders must include the system code in parentheses at the end of the folder name, such as
Game Boy Advance (GBA). If that code is wrong, MinUI will ignore the folder.- A quick tap on the power button triggers sleep mode. After a few minutes, the device auto-shuts down to save battery, so you need a full button hold to boot it again.
- The physical toggle on the right side is a mute switch. If the speaker suddenly seems dead, check that first.
- PortMaster games that bounce back to the menu after a black screen usually need runtimes, not a full reinstall.
What you actually get in the box (and what you need to source)
The TrimUI Brick ships as a clean piece of hardware with a few accessories, but it does not come pre-loaded with a game library. The retail package includes the Brick itself, a USB-C cable for charging, and a microSD card if you purchased the bundled version. The bundled card, when included, is typically a generic 128GB TF card pre-formatted with a base ROM set. Tempting as that sounds, it is worth reformatting it properly anyway, because the factory partition setup is often inconsistent.
The device itself is built around the Allwinner A133P SoC, a quad-core ARM Cortex-A55 chip paired with a PowerVR GE8300 GPU. The 3.2-inch IPS display runs at 1024×768 resolution, which is a genuinely excellent fit for pixel-art era consoles. You get a solid D-pad, four face buttons, shoulder triggers, a USB-C port, a micro-HDMI port, a 3.5mm headphone jack, and that right-side physical mute switch that will confuse you exactly once. The battery sits around 3,000mAh, giving a comfortable four to five hours of play depending on the system being emulated.
What the box does not include: your own ROM files, BIOS firmware binaries, or any guarantee that the stock firmware is the experience you want. All three of those are your responsibility to sort, and the rest of this guide covers how.
For a detailed hardware breakdown, including display quality, button feel, and how the Brick compares to other devices in its price bracket, the detailed hardware breakdown in our TrimUI Brick review covers all of that ground.
Choosing your firmware: MinUI, NextUI, StockMix, or waiting for CrossMix
Firmware choice is the first real decision you make with the TrimUI Brick, and it shapes everything downstream. There are currently four viable options, each with a distinct philosophy.
Stock firmware is what ships on the device. It is functional and familiar if you have used TrimUI devices before, but it is relatively limited in customisation and receives less community support than custom alternatives. Most experienced users replace it within the first hour.
StockMix is a community-modified version of the stock firmware built specifically for the Brick. It retains the familiar stock UI while layering in additional emulator support and quality-of-life patches. If you want something that feels like an improved version of the out-of-box experience, StockMix is a sensible middle ground.
MinUI is the minimalist custom firmware that has become the default recommendation for most Brick owners. It is deliberately sparse: no background music, no animated transitions, no store. What it does have is rock-solid emulation, a clean grid-based interface, and an almost obsessive focus on reliability. Boot times are fast, input lag is low, and the per-system BIOS and ROM folder organisation is logical once you understand the naming conventions.
NextUI is a community fork of MinUI that adds a rebuilt emulation engine, expanded system support, and additional feature layers while keeping the core MinUI structure intact. If you want MinUI’s stability with more headroom for tinkering, NextUI is the upgrade path.
CrossMix OS, the popular custom firmware from the TrimUI Smart Pro community, is still in active development for the Brick. It will be a strong option when it lands in a fully mature state, but it is not yet the stable, complete package it is on the Smart Pro.
For this guide, the setup steps follow the MinUI path, as it is the most documented, the least fussy once installed, and the firmware I personally find myself reaching for first.
SD card size, format, and the FAT32 rule
SD card formatting is not a preference. It is a technical requirement, and getting it wrong leads to data corruption that looks like a firmware bug. The TrimUI Brick can read exFAT partitions without complaint, which is why so many people never bother to reformat. The problem is that exFAT on this device is unstable under certain read and write conditions, particularly when transferring large ROM sets or running background sync tasks. The corruption shows up as files that appear present but will not load, or a device that freezes mid-game and then fails to read the card on reboot.
FAT32 is the only format worth using for reliability. The catch is that Windows natively refuses to format drives larger than 32GB to FAT32, which is where Rufus comes in.
How to format your SD card with Rufus
Rufus is a free, portable Windows utility that overrides Windows’ FAT32 size limit. Here is the process:
- Download the portable version of Rufus from rufus.ie. No installation needed.
- Insert your microSD card via a reliable USB card reader. Cheap, unbranded readers cause their own corruption issues, so use a reputable one.
- Open Rufus. Confirm the Device dropdown shows your SD card and its correct capacity.
- Set Boot Selection to
Non bootable. - Set Partition Scheme to
MBR. - Set File System to
Large FAT32. - Leave Cluster Size at the default unless you have a specific reason to change it.
- Click START and confirm the format prompt.
The process takes one to three minutes. When it completes, you have a clean, blank FAT32 card ready for the MinUI base package.
The SD card validation step most people skip
A fresh format is not the same as a healthy card. I have had cards pass a format, accept a full ROM copy, and then start throwing invisible errors the moment the Brick rebuilt menus or wrote save data. Before you install anything important, eject the card, reinsert it, create a test folder, copy a few hundred megabytes of mixed files, then open several of them directly from the card. If file names look garbled, transfer speed falls off a cliff, or folders reappear with strange timestamps, stop there and replace the card or the reader.
There is another quiet failure point here: Windows may leave you with a GPT-partitioned card if you used a different formatter before Rufus, and the Brick is far happier with MBR. If the device acts like the card does not exist even though your files are all there on the PC, check the partition table before you blame MinUI. Nine times out of ten, the issue is the card prep, not the firmware.
Maximum SD card size: The TrimUI Brick supports large-capacity microSD cards when they are formatted properly and use an MBR partition table. Cards around 128GB or 256GB tend to be the easiest balance of price, stability, and library space. FAT32 also has a 4GB single-file limit, which usually is not a problem for ROM storage but is worth knowing up front.
Installing MinUI on the TrimUI Brick
MinUI installation is a first-boot process. You copy the right files to the SD card, insert it into the Brick, power on, and MinUI installs itself automatically. There is no PC-side flashing tool required.
Step 1: Download the MinUI package. Grab the latest stable release from the official MinUI repository. The release archive contains a MinUI.zip file and a set of device-specific folders.
Step 2: Extract the archive. Use 7-Zip for extraction. Some ZIP tools mishandle the nested compression and produce incomplete output without showing an error. 7-Zip is reliable and usually avoids the weird half-extracted mess that wastes an evening.
Step 3: Copy files to the SD card root. You need two things at the root level of your freshly formatted FAT32 card:
- The
trimuifolder - The
MinUI.zipfile itself
Do not unzip MinUI.zip. Copy the zip file as-is. MinUI’s installer reads the zip directly during the first-boot process. If you extract it, the installation will fail silently or produce an incomplete setup.
Representing the root of your SD card schematically:
trimui/MinUI.zip
Nothing else. No extra folders, no leftovers from the archive tool, no duplicate folder level.
The install mistake that looks like a dead boot
The most common MinUI install failure is not a bad download. It is a bad folder layout. Some archive tools create an extra wrapper folder so you end up copying MinUI-main/trimui/ instead of just trimui/, and the Brick simply sits there like nothing happened. On a Mac, hidden metadata folders can also get copied alongside the real files, which does not always break the install but does make the card structure harder to verify at a glance.
I have also seen people unpack MinUI.zip because that feels logical, then wonder why the Brick boots into the stock environment or hangs at a blank screen. Leave the zip alone. If you can see the contents of MinUI.zip sitting loose on the card, you already took a wrong turn.
Step 4: Insert and power on. Slide the SD card into the TrimUI Brick’s card slot. Press and hold the power button until the screen lights up. You should see a MinUI installation dialogue appear almost immediately. Let it run. The process is usually fast.
Step 5: Remove and reinsert the SD card. Once MinUI finishes installing, power off the Brick and remove the card. Plug it back into your PC. The root of the card will now contain:
Bios/Roms/Saves/trimui/MinUI.zip
The Bios, Roms, and Saves folders are your working directories. Everything from this point forward goes into one of those three.
First boot: what to expect and what to ignore
On your first boot into a freshly installed MinUI with no ROMs loaded, the main menu may appear empty or show only a default games area with nothing in it. This is normal. MinUI builds its menu from whatever it finds in the Roms folder. If the folder is empty, the menu reflects that.
A common first-boot panic is the device landing on a black screen with a small loading spinner and then seeming to stall. That usually means the SD card was not seated properly or the card structure is still wrong. Power off, remove the card, reinsert it firmly until it clicks, and try again.
The complete TrimUI Brick setup checklist (before you touch a cable)
A clean trimui brick setup comes down to doing these five things in the right order. Skipping any step, or doing them out of sequence, is where most issues originate.
- Format the microSD card to FAT32 using Rufus.
- Copy the
trimuifolder andMinUI.zipto the SD card root. - Insert the card into the Brick and power on to let MinUI install itself.
- Remove the card, reinsert it into your PC, then populate the
BiosandRomsdirectories. - Reinsert the card into the Brick and reboot into your loaded library.
That is the entire flow. Everything else in this guide is detail on steps four and five.
BIOS files: locations, naming, and the case-sensitive trap
BIOS files are the firmware binaries that certain emulators need to accurately replicate original hardware behaviour. Without them, some systems refuse to launch entirely, while others run with degraded compatibility, missing audio, or strange boot errors. MinUI is strict about where these files live.
MinUI BIOS folder structure (by system)
In MinUI, BIOS files do not go into one giant dumping ground. Each system has its own subfolder inside the root /Bios/ directory, and the folder names matter. Place the right file in the wrong folder and MinUI behaves as if the BIOS does not exist.
Here is the structure MinUI expects:
/Bios/FC/for NES / Famicom/Bios/GB/for Game Boy/Bios/GBA/for Game Boy Advance/Bios/GBC/for Game Boy Color/Bios/MD/for Sega Mega Drive / Genesis/Bios/PS/for PlayStation 1/Bios/SFC/for Super Famicom / SNES- additional system folders as you add extras
The BIOS filenames themselves also need to be exact. PlayStation is the classic example. scph1001.bin in lowercase is a very different thing from SCPH1001.BIN or scph1001.bin.bin once MinUI starts scanning for a specific file.
The filename trap that looks like a BIOS issue
Windows hides file extensions by default, which is how people end up renaming a file to scph1001.bin while the real filename becomes scph1001.bin.bin. That file looks fine in File Explorer and fails perfectly on the handheld. The result is a fake BIOS problem that sends people hunting through firmware settings when the real issue is one bad filename.
In my experience, BIOS troubleshooting gets faster the moment you enable visible file extensions on your computer and stop trusting what the operating system thinks is a helpful simplification. I have fixed more PlayStation boot failures by correcting names and extensions than by replacing BIOS packs.
For stock firmware and stock-style setups: BIOS paths differ. On stock TrimUI firmware, RetroArch usually reads BIOS files from:
/RetroArch/.retroarch/system/
That layout is flatter and less elegant, but it is the normal location for stock-style firmware environments.
Adding ROMs to the TrimUI Brick
ROM organisation in MinUI is where most setup guides get too vague, and that is why so many first-time owners end up with empty menus. MinUI’s folder detection system relies on a specific naming convention. If the folder name is right, the menu populates cleanly. If the folder name is wrong, MinUI simply pretends the folder is not there.
The double-parentheses rule (this is not optional)
MinUI identifies which emulator core to use for each folder by reading the system code in parentheses at the end of the folder name. The format is:
[Descriptive Name] (SYSTEMCODE)
The parentheses must be standard round brackets, and the system code must match MinUI’s recognised codes exactly. Here are the codes for the most commonly used systems:
| System | Folder Name Example |
|---|---|
| Game Boy | Game Boy (GB) |
| Game Boy Color | Game Boy Color (GBC) |
| Game Boy Advance | Game Boy Advance (GBA) |
| NES / Famicom | Nintendo (FC) |
| SNES / Super Famicom | Super Nintendo (SFC) |
| Sega Mega Drive / Genesis | Sega Genesis (MD) |
| PlayStation 1 | PlayStation (PS) |
| Sega Game Gear | Game Gear (GG) |
| Sega Master System | Master System (SMS) |
The descriptive name before the parentheses is flexible. You can call the folder Portable Nintendo (GBA) or GBA Games (GBA) and MinUI will still understand it, as long as the parenthetical code is correct.
Place ROM files directly inside these folders. Keep it simple at first. You can get fancy with subfolders later.
The folder naming mistakes that waste the most time
A folder can look correct and still fail because of tiny formatting issues. A trailing space before the parentheses, a smart quote copied from a notes app, a full-width bracket from mobile text input, or a system code typed in lowercase can all stop detection cold. That is why a folder copied from a spreadsheet or Notion page sometimes refuses to show up even though it looks perfect.
I have had supposedly broken setups spring to life after nothing more glamorous than renaming Game Boy Advance（GBA） with normal keyboard brackets and removing one invisible trailing space. When ROMs do not appear, I check folder names before I blame the card, the BIOS, or the firmware.
Why games do not show up or launch
Use this checklist before you reinstall anything. Most TrimUI Brick ROM issues come down to structure, naming, or file state.
| Symptom | Likely cause | What to fix |
|---|---|---|
| System folder does not appear in MinUI | Folder name does not end with the correct system code in parentheses | Rename the folder to a valid format such as Game Boy Advance (GBA) |
| System folder appears, but games are missing | ROMs are still zipped, nested too deep, or in unsupported file formats | Extract archives if needed, keep ROMs directly inside the system folder, verify file extensions |
| Game launches to black screen and returns | Missing BIOS file, wrong BIOS filename, or wrong BIOS folder | Check /Bios/ structure, verify exact filenames, enable file extensions on your PC |
| Card reads on the PC but not on the Brick | exFAT format, GPT partitioning, or card reader corruption | Reformat to FAT32 with MBR in Rufus, then test with a different card reader |
| PlayStation games show but fail to boot | BIOS name is wrong, extension is doubled, or cue/bin files are split incorrectly | Verify scph1001.bin, confirm no .bin.bin, and keep PS1 disc files in a clean set |
| New files copied over WiFi do not appear | Sync did not finish cleanly or MinUI has not re-scanned the card yet | Reboot the device, verify the copied files on the card, and retry the transfer on a stable WiFi connection |
Consolidating systems into a single folder
One of MinUI’s cleaner features is the ability to merge multiple systems into one folder when those systems share an emulator core. The most practical example is Sega. Sega CD and Sega 32X files can live inside the Sega Genesis (MD) folder alongside standard Mega Drive ROMs, and the emulator can handle all three without separate folders cluttering the menu.
This works because MinUI selects the emulator based on the folder name, not the file extension alone. As long as the ROMs you are combining genuinely use the same emulator core, the consolidation stays tidy and works well.
Hiding folders with .disabled
MinUI supports a folder-hiding trick that is genuinely useful for keeping the main menu clean. Adding .disabled to the end of any Roms subfolder name removes it from the main menu. The folder and its contents remain on the card and stay accessible through Collections, but they no longer appear in the default browsing view.
The practical use case is simple. You might keep a Tech Demo (GBA).disabled folder for oddities, patches, or test files that you still want accessible without seeing them every time you open the menu.
Transferring ROMs wirelessly with Syncthing
Syncthing is a file sync tool that, when installed on the TrimUI Brick through a compatible app workflow, lets you move ROMs wirelessly from a PC or phone over your local network. It saves you from constantly pulling the SD card out of the device every time you want to add a few games.
The setup process is straightforward in concept. Install Syncthing on the Brick, install it on your computer, pair both devices with their device IDs, and point the sync path at the Roms directory on the card. Once that is done, new files can flow across automatically.
The catch is WiFi. The TrimUI Brick’s wireless can be finicky. SSIDs sometimes do not appear on the first scan, or the connection looks active but drops long transfers. The reliable approach is not glamorous: rescan, toggle WiFi off and on, reboot the device if needed, then try again. Once it locks onto a stable connection, it usually behaves.
I still prefer direct SD card transfers for the initial bulk load. Syncthing becomes most valuable after setup, when you are adding a handful of games, patches, or translated ROMs and do not want to break your desk routine every time.
PortMaster: ports, runtimes, and the black screen problem
PortMaster is one of the Brick’s most interesting add-ons because it opens the door to native Linux ports instead of pure emulation. That means selected PC and indie-style games can run directly on the device if their engine support and runtime dependencies line up.
The black screen problem is where most people hit a wall. A port installs, you launch it, the screen goes black, and then it dumps back to the menu a few seconds later. That looks like a failed install, but it usually is not. It is more often a missing runtime or an incomplete download.
PortMaster ports depend on runtime libraries for specific engines. SDL2, LÖVE2D, and other frameworks each need their supporting files present before a game will launch cleanly. The fix is to install the required runtimes for the ports you want, or just pre-load the lot if you want fewer surprises later.
You can also pre-seed runtime files manually in a location such as:
/Roms/Apps/PortMaster/PortMaster/libs/
That helps if you are preparing a card on a PC before the Brick ever touches WiFi.
The false-success install problem
A PortMaster install can finish with no obvious error and still be incomplete. That usually happens when WiFi cuts out halfway through a runtime download or the card is so full that the install writes part of a package and silently fails on the rest. The app may still show up in the menu, which makes the later black screen even more misleading.
In my own setup routine, I leave generous free space on the card before I touch PortMaster and I always test one known-good port after installing runtimes. If that first test fails, I stop and fix the underlying environment instead of stacking ten more broken installs on top of it.
Power button, mute switch, and the two hardware quirks nobody reads about
The TrimUI Brick has two hardware behaviours that generate a disproportionate number of support questions, and both are features, not bugs.
The power button. A short tap on the power button puts the device into sleep mode. This looks like shutdown because the screen goes dark and the device seems dead. It is not dead. It is sleeping. However, MinUI sleep has an auto-shutdown timer. If the device sits long enough, it fully powers down to preserve battery. To wake from sleep, a short tap works. To boot from a full shutdown, hold the power button for a couple of seconds until the screen lights up. Many new owners tap once after auto-shutdown, get nothing, and start wondering if the battery failed. Hold the button.
The mute switch. On the right side of the TrimUI Brick, there is a physical toggle that silences all audio output. It is positioned where it can be nudged by accident during normal handling. When muted, no menu sound or game audio comes through the speaker, and OS settings will not override it. I have spent an embarrassing amount of time checking audio menus on a perfectly healthy device before noticing the physical switch had been bumped.
N64, Dreamcast, and the analog stick reality check
The TrimUI Brick can technically run Nintendo 64 and Sega Dreamcast games through supported cores. Performance on lighter games can be acceptable. The real limitation is control, not raw capability.
N64 was built around an analog stick. The Brick has a D-pad. Mapping three-dimensional movement to a four-directional pad produces controls that range from awkward to deeply irritating depending on the game. Platformers and racers suffer the most because they rely on gradual movement and directional nuance.
There are workarounds. Some cores allow digital-to-analog mapping, and a few games remain playable if you are stubborn enough. But if N64 or Dreamcast is your main reason for buying a handheld, the Brick is not the ideal match. It shines on systems that were designed around a D-pad in the first place, which is exactly why it feels so good with Game Boy, SNES, Mega Drive, and PS1-era libraries.
Frequently asked questions
Does the TrimUI Brick come with games preloaded?
The hardware itself does not include a guaranteed library of commercial games. Some bundles include a pre-loaded SD card, but the contents vary by seller and are often messy enough that you will want to rebuild the card properly anyway.
What is the best SD card size for the TrimUI Brick?
For most people, 128GB or 256GB is the sweet spot. It is enough space for a big retro library without turning the card into a junk drawer you never clean up.
How do I format an SD card for the TrimUI Brick?
Use Rufus, select MBR, format to Large FAT32, and verify the card with a quick copy-and-read test before you install MinUI. Do not assume a successful format means the card or reader is healthy.
Where do BIOS files go on the TrimUI Brick with MinUI?
Put them inside /Bios/ using the system-specific subfolder MinUI expects, such as /Bios/GBA/ or /Bios/PS/. Exact filenames matter.
What is the best custom firmware for the TrimUI Brick?
MinUI is still the easiest recommendation for most users because it is stable, clean, and well understood. NextUI is attractive if you want more features without abandoning the MinUI style. StockMix is a sensible option if you prefer a stock-like experience.
How do I add ROMs to the TrimUI Brick?
Create correctly named folders inside /Roms/, using the right system code in parentheses at the end of the folder name, then copy your ROM files into those folders. If the code is wrong, MinUI will ignore the folder.
Can the TrimUI Brick play N64 games?
Some N64 games will run, but the lack of an analog stick makes many of them unpleasant to play. Treat N64 as a bonus experiment, not the device’s core strength.
How do I set up Syncthing on the TrimUI Brick?
Install Syncthing on the Brick and your PC, pair both devices using their IDs, then set the sync folder on the handheld side to the Roms directory. Expect to spend a little time wrestling the initial WiFi connection into behaving.
What does the mute switch on the TrimUI Brick actually do?
It physically disables audio output. If your sound seems gone for no reason, that switch should be the first thing you check.
Why do PortMaster games show a black screen on TrimUI Brick?
Most of the time it is a runtime issue, a partial install, or a storage problem, not a faulty port. Verify the runtime packages first and make sure the card still has comfortable free space.
Why does the TrimUI Brick turn off when I press the power button?
A quick tap usually sends it to sleep, and after a short idle period it fully shuts down to save battery. If you want to start it again from that state, hold the button instead of tapping it.
Can I use the TrimUI Brick without an SD card?
No. The SD card is not optional storage on this device. It is the working medium for firmware, ROMs, saves, and the rest of the setup.
Final thoughts
The trimui brick setup process has more moving parts than you might expect from a device this small, but none of the steps are actually difficult once you understand why they matter. FAT32 is not overkill. It is the difference between a stable library and a card that slowly sabotages you. The parenthetical folder naming rule in MinUI is not arbitrary. It is how the firmware decides which emulator core to load. The BIOS subfolder structure is not nerdy theatre. It is the difference between a game launching and a black screen that sends you in circles.
Get those three things right, format, folder names, and BIOS paths, and the rest of the device starts making sense very quickly. Survive the power button learning curve, avoid the mute switch trap, and treat N64 as an occasional party trick instead of a buying reason. Once you do that, the TrimUI Brick becomes exactly what it should be: a compact, reliable, genuinely excellent handheld for classic systems, and a trimui brick setup you only need to do properly once.