EZ-Flash IV Guide
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Prerequisites
You'll need:
- EZ-Flash IV
- GBA / GBA SP / GB Micro / DS / DS Lite
- Micro SD card formatted to FAT32
- Micro SD to USB adapter
- PC
(TAR.GZ, 384 KiB)
Contents of the supplementary files:
- ezfla_up.bin: EZ-Flash IV firmware 2.05. (BIN, 1.14 MiB)
- KEYSET.CFG: Configuration file that defines custom shortcuts. (CFG, 1.17 KiB)
Firmware
The EZ-Flash likely comes with a firmware below 2.00 (mine came with 1.75). Before firmware 2.00, EZ-Flash users needed to use a custom PC application to patch ROMs and transfer them to the SD card. There was also a 78-game limit on the EZ-Flash, regardless of the size of the inserted SD card.
Firmware 2.00 fixed the 78-game limit and added the ability to patch ROMs on-the-fly, so now users can copy untouched ROM backups directly to the SD card and patch them at load time. This makes playing ROMs a lot easier, so I highly recommend updating the firmware to 2.00+. The current firmware at time of writing is 2.05.
Updating Firmware:
- Download the supplementary files for this guide.
- Connect the SD card to your PC.
- Copy ezfla_up.bin from the supplementary files to the root of the SD card. If KEYSET.CFG is not in the root of the SD card, copy it as well.
- Eject the SD card and insert it into the EZ-Flash.
- Boot the console while holding R. The EZ-Flash will automatically begin updating.
- After the update is finished you can delete ezfla_up.bin from the SD card. Keep KEYSET.CFG on the card.
- You can check which firmware the EZ-Flash has by looking at the number in the upper-right corner of the EZ-Flash's home screen.
Adding ROMs
- Make backups of your legitimately-owned GBA cartridges.
- Connect the SD card to your PC.
- Add the ROMs to the SD card. Organize them any way you want.
- Eject the SD card and insert it into the EZ-Flash.
I create a "roms" directory in the root of the SD card and put the ROMs in there. Inside the "roms" directory I put two directories: one for the few ROMs I play a lot and one for all the others.
Loading ROMs
The EZ-Flash offers two ways to load ROMs: NOR flashing and on-the-fly patching. NOR flashing writes the patched ROM into the EZ-Flash's internal NOR flash memory and loads it from there, while on-the-fly patching loads the ROM and patch directly from the SD card into the GBA's RAM.
Advantages of NOR flashing:
- Games load from NOR very quickly.
- Large ROMs (32 MiB) can be loaded. These ROMs are too large to be loaded using on-the-fly patching.
Disadvantages of NOR flashing:
- NOR flash memory is only 256 MiB. ROMs are inflated to 8 times their flat file size when written to NOR; a single 32 MiB ROM fills up NOR, as do two 16 MiB ROMS or four 8 MiB ROMS.
- Initial setup is necessary (the ROM must be written to NOR), and this can be very slow depending on the size of the ROM.
Advantage of on-the-fly patching:
- The number of ROMs that can be stored is limited only by the size of the SD card.
- Patch files are kept on the SD card and can be backed up, so the ROM does not need to be re-patched every time it is run.
Disadvantages of on-the-fly patching:
- The initial creation of the patch file can be slow, and ROM loading can be slow even with an existing patch file as the patch is applied.
- Only 16 MiB or smaller ROMs can be loaded with on-the-fly patching.
Playing ROMs
On-the-fly Patching Mode:
- Boot the console. You'll reach the EZ-Flash home screen.
- Use the D-pad to navigate to the icon with a globe (it should start there by default) and press A.
- An info box will pop up saying "Starting the file manager". Press A again.
- Highlight the directory called "EZ-Disk" and press A. This will take you to the SD card.
- Navigate to your ROM of choice and press A.
- An info box will pop up saying "progressing". This is the EZ-Flash patching the ROM. Wait for the patching to complete. If an info box pops up saying "PSRAM is not enough", you'll need to load the game using NOR flashing.
- The game will start.
NOR Flashing Mode:
- Boot the console. You'll see a home screen resembling a PC desktop.
- Use the D-pad to navigate to the icon with a globe (it should start there by default) and press A.
- An info box will pop up saying "Starting the file manager". Press A again.
- Highlight the directory called "EZ-Disk" and press A. This will take you to the SD card.
- Navigate to your ROM of choice and press Select.
- An info box will pop up saying "Write NOR Flash Y/N". Press A. If an info box pops up saying "NOR Space is not Enough", you need to delete games from the NOR in order to make room.
- Three info boxes will appear in succession. Wait for all of them to finish.
- From then on, when you enter the file browser, the NOR-flashed ROM will appear underneath the "EZ-Disk" directory. The ROMS will listed in the order they are stored in memory on NOR.
- Highlight the ROM you want to load and press A.
- The game will start.
Deleting ROMs from NOR
- Boot the console. You'll reach the EZ-Flash home screen.
- Use the D-pad to navigate to the icon with a globe (it should start there by default) and press A.
- An info box will pop up saying "Starting the file manager". Press A again.
- Highlight the ROM you want to delete and press Select.
NOTE: NOR flash memory is read from and written to sequentially--the last thing to be written is the first thing to be deleted. ROMs can thus only be deleted from the NOR in reverse order that they were written. For example, if you've written Game 1, then Game 2, then Game 3 to NOR flash memory, and you want to delete Game 2, you must delete Game 3 first.
NOR memory management can be tricky when ROMs of different sizes are written to it. To easily figure out what will fit, take the flat file sizes of the ROMs you want to write and add them up. The total cannot exceed 32 MiB.
NOR stuff is complicated, and I'm willing to wait through the loading time for on-the-fly patching, so I only use NOR flashing to load games that are too big for on-the-fly patching.
Saves
Save files are located in a directory called "SAVER" on the SD card. Saves are not deleted when a ROM is deleted, either from the SD card or from NOR. When a ROM is running, the EZ-Flash does not write saves directly to the SD card because writing to the SD card is very slow. Instead, the EZ-Flash creates a temporary save file in its on-board memory, and when the EZ-Flash is power-cycled, it then writes the save out to the SD card. If you want to copy a save file off of the SD card, turn on the EZ-Flash at least once to make sure the most recent save has been written to the SD card.
DS ROMs and Homebrew
If your DS / DS Lite has FlashMe installed, it's possible to use the EZ-Flash to load DS ROMs and homebrew from the GBA slot. Apparently you just have to put a DS ROM onto the SD card, then plug any DS cartridge into Slot 1 to make the console think it's reading the ROM from Slot 1. I have a DS Lite with FlashMe Stealth v8 and I have NOT been able to get this to work. If you do, I'd love to hear about it.
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[Last updated: 2026-01-21]