Monday, December 28, 2020

The EverDrive GB X7 - The Ultimate 8-bit Game Boy/Color Flash Cart?

EverDrive GB vs. EverDrive GB X7

For too long, the Game Boy and Game Boy Color had been rather neglected by the flash cart builders.  The old cartridges by companies like Bung faded out of existence as Nintendo sued Bung out of existence.  There were a few more recent cartridges like the 64MB EMS Smart Card, but it was really klunky to use and had poor game compatibility.  A few cartridges were more focused on music production than game playing.  In 2014 Krikzz released the EverDrive GB, a flash-based device with an FPGA with enough resources to handle basic games.  I bought one then and was satisfied with it, as I indicated in my review.  Three years later he released the SRAM-based EverDrive GB X-series.  Having finally acquired an EverDrive GB X7, let me share my thoughts and views of the device and try to answer the question, "Is it the Ultimate GB/GBC Flash Cart?"

The EverDrive GB X7 is Krikzz' most fully featured and most expensive Game Boy/Game Boy Color flash cart.  It retails for $129.99, but if you do not want to wait for the long import (assuming you are in the USA) you can spend a few dollars more and import it from Stone Age Gamer.  SAG an authorized reseller of Krikzz products and that's what during Krikzz' annual Black Friday sale, which takes 20% off the retail price.

Introduction to the X7 and its Features

File Browser, GBC Version

Compared to the original EverDrive GB, the GB X7 offers many features.  The largest difference is the loading times for games.  The old EverDrive GB loaded games into flash memory.  This required the device to erase the flash then program the flash with a ROM file from the microSD card.  Krikzz was kind enough to show the progress of the flashing with a series of periods, one for every 64KiB of storage space erased or written.  Game Boy games range in size from 32KiB to 4MiB (there is one 8MiB GBC game).  The EverDrive GB would have to erase as much flash as the new game needed and then copy the game over, a process which could take up to a minute with the largest games.  All EverDrives use a pair of logic level transceivers, so they are safe to use in your original systems.

Select Menu

The EverDrive GB X7 is SRAM based, it has an 8MiB SRAM chip inside into which it copies a ROM file from the microSD card.  This operation is far quicker than having to erase and reprogram a flash chip.  Games generally load far more quickly on the X-series than the old GB as a result.  Because it used flash memory to store games, the old EverDrive GB could load that game on bootup even without a microSD card.  Also, if you wished to continue to play the game that was previously flashed, all you had to do was press start and that game loaded instantly.  Without a microSD card the X-series is useless.  Also for this reason, the X series is incompatible with the mod which allows for some games to work via the N64 Transfer Pak.

Options Menu

The menu has not changed much with the X-series over the old EverDrive GB.  On a GBC the menu will take on a green text on black background, but the menu looks pretty much the same on the monochrome machines.  There many more options on the Options Menu on the X7 than the older EverDrive GB.  You can turn cheats on and off, swap the A and B buttons function in the file browser and menus, hide the OS's directory and disable the in-game menu button.  The recently played list can store up to 11 games and the random game feature is new.  16 Game Genie codes can be input and will be stored on a per-game basis in a text file created once a code is entered.  You can also edit this text file to spare yourself of having to enter the codes via the Game Boy.  There is a built-in Diagnostic Test.  The RTC can be set to the true time and every game that uses an RTC can have its time set independently.  When you select a ROM, the ROM info screen gives you useful information, such as whether the game supports SGB, whether it is a GB, GB/GBC hybrid or a GBC exclusive game, the mapper, ROM and RAM size and whether it supports a real time clock.

Real Time Clock and Mapper Support

System Information (Cropped to Obscure Serial Number)

One of the most important new features in the X7 is the support for a Real Time Clock for those Game Boy and Game Boy Color ROMs that use one.  The GB X7 has a real time clock chip which is battery backed as well as 128KiB of battery backed SRAM for save games and music carts like nanoloop and LSDJ.  Pokemon Gold, Silver and Crystal can now be played to their fullest without having to grab a soldering iron to exchange a dead battery.  The GB X7 and X5 automatically backup the SRAM to a file on your microSD card when you change to a new game.  The save will remain in memory even after powering off the system.


Mapper support in the X7 has not otherwise improved over the old GB.  They both support 32KiB (no mapper) games, MBC1 games, MBC2 games, MBC3 games and MBC5 games.  Licensed games using a real time clock almost invariably use the MBC3 mapper, so you no longer need RTC-setting hacks for those games (see the list below).  They should be fully functional on the X7.  Certain MBC5 games supported a rumble motor, but the EverDrives do not have a motor so rumble is unavailable for those games, but they otherwise play.

RTC Setup

There are many, many more mappers than the "canonical five" identified in the previous paragraph.  The other ten known licensed mappers are MBC1 Multicart, MMM01, TAMA5, MBC6, MBC7, Mani 74’161, Game Boy Camera, MBC1 Sonar, HuC-1 & HuC-3.  In addition, there are fourteen known and emulated unlicensed mappers, BBD, Hitek, Sintax, NT old type 1, NT old type 2, NT new, Li Cheng, Last Bible, Liebao, Pokemon Jade/Diamond, Wisdom Tree, Sachen MMC1, Sachen MMC2, Rocket Games.  The EverDrive series simulates none of these mappers or any additional hardware they may provide and thus the games using them are almost invariably unplayable.  The EZ-Flash Junior does support MBC1 Multicart, but the only benefit to this mapper is some very basic Super Game Boy support for some of the Japanese multicart releases.


Here is the list of unusual licensed Game Boy and Game Boy Color ROMs that use an unusual mapper or some kind of extra hardware :

As you can see, most of these games were released in Japan only or require special hardware to work properly or possess very little usefulness with a flash cartridge.  Rumble Paks used an additional AA battery for the rumble and were oversized.  They also comprise a tiny fraction of the Game Boy and Game Boy Color's library.  Saving in Pocket Monsters - Crystal Edition, which uniquely supports 64KiB of SRAM, works.

In-game Menu & Save States

Game Menu

The other important new feature for the X7 is the addition of the in game menu for save state support.  The way the in-game menu is accessed is by physically pushing on the GAME text embossed on the top front of X7's cartridge housing.  Underneath this plastic is a switch which will stop the game in progress and bring up the menu.  There you can save a state, load a state or return to the file browser.  This feature is very useful for fine tuning your game performance, avoiding having to write down passwords, saving your game when your batteries are about to die or you have to put the console away.  If you choose the Back to Menu item, the boot screen will appear again but it beats the power cycle required for the old EverDrive GB.  A few games, Battletoads, Donkey Kong, Mr. Nutz, may not recognize the in-game menu button or load a save state correctly.  

ROM info

With the Super Game Boys the X7's in game menu works, but if you go Back to Menu, the Super Game Boy border will not reset to the default border.  You can still choose one of the built-in borders and an SGB-enhanced game will overwrite the border with its own. Still, it might be fun to play Super Mario Land using Donkey Kong's border.  If the Super Game Boy has a pre-selected palette for a first party Nintendo game, that palette will not show up until you press reset on the SNES.  This reset for pre-selected palette was also required on the old EverDrive GB.

Power Consumption

Loading, no Erase, No Write indicators

Power consumption is something Krikzz takes seriously.  He uses low power and ultra low power memory chips whenever possible to reduce the power consumption of his cartridges as much as possible.  Hopefully this should allow the included battery to maintain the battery backed save memory and Real Time Clock for as long as possible.  It should take less energy to write data to SRAM compared to flash memory.  

In Game Menu

The EverDrive X-series is compatible with every mainstream console or add-on which can play Game Boy games, the original DMG Game Boy, Super Game Boy, Game Boy Pocket*, Super Game Boy 2, Game Boy Light, Game Boy Color, Game Boy Advance, Game Boy Player and Game Boy Advance SP (frontlit and backlit).  I put an asterisk next to the Pocket because the earliest PCB revision of the X-series was not Pocket compatible, but the Rev. B boards fixed this issue.  I found the shell of my X7 had a tighter fit in my Pocket than regular cartridges or the old EverDrive GB.  The X7 fit just fine in my other handhelds and my Supers and my Player.   

Running the X7 on the amperage-starved Game Boy Pocket is something of a challenge.  The Pocket uses triple-A batteries whereas other Game Boy handhelds use double-A batteries.  While both AA and AAA batteries provide a nominal 1.5v, the amperage of a AAA battery (860–1,200mAh) is less than half that of an AA battery (1800–2850mAh).  The capacity was sufficient, just barely, for a Pocket running regular cartridges.  Now add in the extra energy drain required for a flash cart and you are really starting to test the power output of those batteries.  You will only get so many game swaps out of a pair of Alkaline AA batteries, best look for cheap lithium batteries for on-the-go play.  If you want to add in a backlit IPS screen, then even the mighty GBC can start to buckle under the power drain.  At that point you should really be looking at a CleanJuice-type rechargeable battery solution.

Installation Tips

Installing the firmware for the X7 is just like the older GB, unzip the OS update file with the folder GBCSYS and then copy that directory onto the root directory your micoSD card.  I would suggest a freshly formatted FAT32 microSD card and copying your ROM archive using the XCOPY command from a command line.  The XCOPY /E command will copy all files and all directories in alphabetical order, which is helpful because there is no file sort option on the EverDrive GBs.  A program like DriveSort will also work to sort.  

One issue that the X7 struggles with is the consistency of the speed of loading ROMs.  While smaller ROMs generally load faster than larger ROMs, I have found that this is not always the case.  With the old GB, the speed at which a ROM loaded was always directly proportional to the ROM's size and whether it was being loaded on a GBC-based device with its faster loading times or a DMG-based device, which loaded slower.  Still, the slowest time a ROM took to load was about 15 seconds, but sometimes even small games took longer to load than other times.  I believe a fresh format and copy of the archive directory may have helped matters here.  Also, it is wise when dealing with these devices never to overwrite files, this creates fragmentation which the EverDrives find harder and slower to deal with.  


When Krikzz released the EverDrive GB, there was no competition that could play the library of Game Boy and Game Boy Color games nearly as well.  Now there are other, cheaper solutions which actually prioritize games as well as music-making, such as the EZ-Flash Junior and the ElCheapoSD from BennVenn Electronics.  But the EZ-Flash Junior is a battery hog and the ElCheapoSD does not support RTC.  While the competition is out there, Krikzz is still the king of the Game Boy flash carts.


  1. This gets a thumbs up from me solely because it uses the Atari 8-bit font and a lot of the color scheme!!

  2. Hi! Just a bit of information that I did not see in your post. The games that support the rumble function actually could allow access of the rumble functionality by way of using the GB/GBC codebreaker device. Just set the rumble function to the "game" setting and the built-in rumble of the codebreaker will replace the game's, although this may not be 100% exact due to different rumble hardware and cart physical differences, it should work as intended. Tarzan by default does not rumble, though the game was designed to rumble and was most likely cut due to costs.