EZ-FLASH Junior – Gameboy Flash Cartridge Review

The EZ-FLASH Junior is a flash cartridge that has the ability to store the entire Gameboy and Gameboy Color game library. Let’s see how well it performs as we break down all of it’s features in this EZ-FLASH Junior Cartridge review!

There are a number of flash cartridges on the market with a range of features and price points. So what does the EZ-FLASH offer?


  • Works on all Gameboys that support Gameboy games (DMG to Advance SP)
  • ROMs are stored on a MicroSD card and can be loaded without the use of special software
  • Easy to navigate user interface
  • Features a real-time clock
  • Saves to SD card
  • Upgradeable firmware
  • Replaceable battery


  • Confusing setup process
  • Specific SD card requirements
  • No support for cheat codes
  • Depletes batteries quicker than a regular cartridge

Competing against the line of Everdrive cartridges, the El Cheapo, and a few older options, the EZ-FLASH Junior is a good option for those who don’t want to spend almost $150 for the Everdrive X7, but still want a lot of features to enjoy the entire Gameboy library of games.


For only about $50, you can purchase the EZ-FLASH Junior and be playing all your favorite games in no time. Prior to the Junior, the only flash cartridge on the market with a real time clock (required to play a number of games such as the ever-popular Pokemon Gold, Silver, and Crystal) was the Everdrive X7. That meant that if you wanted to enjoy games that utilize this feature, you needed to spend a lot of money. The Junior changed this in a huge way when it released; charging a third of what the X7 cost. Since then, a number of other cartridges came to market with RTC functionality, but none offered a lower price tag and more features. For that reason alone, the Junior is an excellent option for anyone looking to purchase a flash cartridge.


This cartridge has everything you need to enjoy the full Gameboy library. It features a 64Mbit Mask ROM which is large enough for every single authentic game (most homebrews will also fit, but some may be too large). The majority of released games for the Gameboy and Gameboy Color are 32Mbit, with only a handful actually using the entire 64Mbit provided.

EZ-FLASH Junior Internals

As far as game saves go, this cartridge handles them perfectly. All saves function exactly as they do if you were using an original cartridge, but instead of being permanently stored on an SRAM chip, the save files are stored on the SD card. After you save your game, it is temporarily stored to memory; then when you reset the cartridge (with a well-placed button on the front), that save data will be transferred from memory to the SD card.

Some of you may be thinking something along the lines of “if I don’t reset the cartridge my saves will be lost when I turn off the Gameboy”! Well don’t worry about that! The save data will be stored in memory until you power it on again. So even if you forget to reset the cartridge, your saves won’t be lost! Just remember that there is an on-board battery in place to power the RTC and keep saves that are stored in memory. If that battery runs dry, your saves will be lost, unless, of course, they are on the SD card.

Speaking of the battery, this cartridge includes one on-board CR-1220 that is easily replaceable. It is not soldered on the board, it just slides into a small holder. This is a nice addition as not everyone enjoys re-soldering a battery every few years.


When you first receive your cartridge it will come without an SD card, which means you are required to load the firmware and any of your ROMs.

To get started, you will need an SDHC card ranging from 4GB to 32GB. Anything larger than that is an SDXC and is not officially supported (but many do work without issues). A 4GB card is all that is needed to store the entire Gameboy and Gameboy Color library, but as they are hard to come by, I recommend this card. It is 16GB and less than $10.

Once you have your card, simply go to the EZ-FLASH website and download the latest kernel and firmware versions. At the time of writing this, that would be Kernel 1.05e and Firmware 5 Release Candidate. Extract the files.

You can then format the SD card (Fat-32 and 32K allocation size), and drag the update_fw5.gb and exgb.dat files onto the root of the card. Create two folders on the root of the card, one titled GB and the other titled GBC. These can be filled with your Gameboy and Gameboy Color ROM files.

Now that the SD card is setup, you can insert it into the EZ-FLASH Junior. When the cartridge is turned on in your Gameboy for the first time, it may take a few seconds to initially load. Once loaded, scroll down in the menu and select the update_fw5.gb option. This will run the firmware, and update your cartridge to the newest version. Note that while it is updating, the screen may flicker constantly. This is normal, do not shut the Gameboy down until it is done and tells you to restart! Once the next boot, you can select any of your ROMs and start playing!

You’ll notice my menu has a SAVER folder in it. That is normal, but it won’t appear until after your first save has been transferred to the SD card. When your first save is transferred, it may take a few more seconds than subsequent saves as it is creating the directory.

One more thing to do before the setup is fully complete! Make sure you set the real time clock. When in the menu, you can click the SELECT button to go to the SET menu. Press A and then you can set the date and time.

EZ-FLASH Junior Clock Set

You may also notice an AUTO SAVE feature on this screen. By selecting this, your game saves will automatically be transferred from memory to the SD card instead of happening on the next boot. This is a great feature to have, but it seems to be buggy (at the time of writing this, I will update this post if future software releases fix this). Sometimes the auto-save feature will cause the system to freeze. Because of this, I recommend leaving this option unchecked.


If you’ve read this far, you are probably surprised as the entire review has been fairly positive up to this point! Well it’s time to point out some flaws I’ve noticed throughout my time testing this card.


The first thing to point out is that this cartridge lacks the ability for cheat codes. While that may not be an issue for some gamers, many do prefer to modify original games for a couple reasons. To change the playability, change the difficulty, or sometimes just for cosmetic reasons. If cheats are something you enjoy using, just note that this cartridge will not support them! EZ-FLASH has stated that they do not plan on adding that ability anytime soon. The company is currently working hard on fixing current bugs, and expanding the cartridge’s compatibility with more Nintendo devices (notably the Super Gameboy for the Super Nintendo).


Speaking of the Super Gameboy, does this cartridge work with one? Technically, yes, it does. Unfortunately there are some bugs, but usually just reinserting the cartridge a few times will get it to work for you. Some games that had game-specific screen borders on the Super Gameboy do not show their specific border, and instead only show the generic Super Gameboy border. Also, note that this cartridge is compatible with the Gamecube Gameboy Player. Always run firmware updates from an actual Gameboy though, and not from the Gameboy Player or Super Gameboy.


Firmware 5 cleared up a lot of issues with initial setup which is great. When I first got the cartridge, I was using firmware 3 to initialize it. With older firmware (4 or earlier) the cartridge would not boot on Gameboy Color’s with certain motherboard revisions. Basically, if the Gameboy motherboard revision (CPU 01, CPU 02, etc.) did not have a CPU prefix, it would not load the cartridge! I personally had 9 Gameboy’s available at the time, and only one of them were compatible with that firmware.

Due to the firmware not loading, the cartridge would just stay at the “Loading…” screen on boot, and eventually throw a “Micro SD Initial Error!” message. If you were unlucky and did not have a compatible Gameboy, you would not be able to boot the cartridge and apply the newest firmware.

Real Time Clock

The majority of this issue has been resolved with firmware 5, but there are still some lingering bugs that need to be ironed out. Previously, the RTC would slowly creep to the future every time you saved your game. You will be happy to know that as long as you are using firmware 5 or later, the RTC will function correctly for all official Nintendo games.

The only known issue at the time of writing this article with the RTC is with the popular ROM hack, Pokemon Prism. Unfortunately there is an incompatibility with the RTC in the game, and on the cartridge. Both the developers of Pokemon Prism and EZ-FLASH are working together to resolve this issue, and hopefully it can be dealt with soon!

Future Support

Getting support directly from EZ-FLASH is not the easiest (excuse the pun?). This is definitely a “made in China” product, and the support reflects that. Your best bet to get in contact with actual employees from EZ-FLASH is to use the GBATEMP forums. EZ-FLASH is fairly active there, and I have never waited more than 24 hours for a resolution to my questions. To get better support my best suggestion would be to purchase your cartridge from a supplier like Handheld Legend, or Retro Modding. This way if an issue arises, these businesses can replace/repair the cartridge as EZ-FLASH normally does not do that directly.


I hope this EZ-FLASH Junior cartridge review has helped you with coming to a conclusion if it is the right flash cartridge for you! Although there are a few bugs that may pop up along the way, they definitely pale in comparison to the vast amount of features you receive for the price.

Do you already have one of these cartridges? Leave a comment with any questions you have and I’ll be sure to answer them all!

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