OK so lets say you want to play the real Super Mario Brother 2. The one that was released in Japan only because they said it was too hard for North American gamers. FCEUX will run the ROM, however you MUST have the disksys.ROM file for the Famicom System. The disksys.BIN file found all over the internet WILL NOT WORK!!!!

You need to use Google to find the disksys.rom file. It's out there, I have a link but I'm not sure if I'm allowed to post it, ADMIN if I am let me know and I'll edit this post.

Here is the most important part!! EXTRACT the DISKSYS.ROM file from it's ZIP archive and RENAME IT exactly like this: disksys.rom in ALL LOWER CASE!! DO NOT put it back in a zip, it has to be the uncompressed file to work. I banged my head for an hour trying to figure out why FCEUX wouldn't load the #$%^ file. First because it was zipped, and then second because it was named in all caps. File name MUST BE LOWERCASE!

Next FTP into your Pi and put the renamed disksys.rom file into this directory "/home/pi/.fceux. You are going to have to type that out because "/.fceux" is a hidden folder. so when you are done the path to the file looks like this "/home/pi/.fceux/disksys.rom"

And that should be it. My system boots up the Famicom Disk games no problem now. And remember the "quotation" marks are just for reading the instructions here, don't use them when you are trying to move your files around.