Just had a person come on IRC with an issue with the EZ4 and the Super Retro Advance for the SNES (a device that allows GBA carts to be played with a SNES using the SNES input and its own video output). The issues raised felt worth noting in a thread like this. Here are the images provided on IRC http://tinypic.com/view.php?pic=2wlvl2d&s=8 http://tinypic.com/view.php?pic=2druv5e&s=8 http://tinypic.com/view.php?pic=24pcmyt&s=8 They appear to show the same thing that happens when you try to run a stock dump of the GBA loader in an emulator. To that end I concluded that the device dumps the ROM from the cart and otherwise sorts the saves (saves are fairly simple electronics as far as such things go http://problemkaputt.de/gbatek.htm#gbacartbackupids , not as much as the DS http://problemkaputt.de/gbatek.htm#dscartridgebackup but still simple enough to implement on basic chips). Flash cart users*, EZ4 or otherwise, should probably be aware of this. You can probably get an older style NOR flash cart to work but it will just be a single game affair, more modern alternatives include the EZ 3 in 1 if you want to reflash with a DS every time or a fire linker/fire card clone. For the NOR style carts you will probably want to flash a single game without a loader as well -- the loaders often did things like load the loader, set the page in the NOR to read from and then reset into the game much like newer PSRAM based devices. Personally I would say get a GB player setup sorted instead if you want this sort of thing, or possibly get a means to dump GBA saves (not sure what exists in the arduino/rasp pi world right now) and an emulator. *technically the as yet undumped GBA Shrek Video titles will probably also be troubled.