For use with FamiCom and the FamiCom Disc System. Has 4Mb of RAM to load games into. It requires a FDS to back games into, you can copy FDS disks as well as backup carts. It is compatible with more games than people think. A great device to own if you have a way of dumping and writing to FDS disks from your pc... I say it beats dr pc jr. It doesn't keep games in RAM so you have to keep loading them like most copiers. It works with all the dragonball games :) not worth having really because unless you own all the games you will ever want, and want to back them up onto FDS disks its useless.