THIS IS VERY IMPORTANT. EMULATING THE FDS IS NOT JUST A MATTER OF DOWNLOADING AN EMULATOR AND A GAME ROM. PLEASE FOLLOW THESE STEPS. 1) Download FCEUX, it's an emulator that supports all forms of the 8-Bit Nintendo console including the Famicom Disk System. 2) GO TO THIS LINK and download "DISKSYS.ROM" - http://www.emuparadise.me/biosfiles/Nintendo_Disk_System_Boot_Sector.zip - Listen, many other sites claim to have something called the FDS Bios Rom... THEY DON'T. They even have something you can download and open in the emulator but you're going to see "BATTERY ERR.O2" and you won't be able to open any FDS games. 3) Put it in a folder (named something like "FDS Bios"). The ONLY file that works is DISKSYS.ROM (8kb). Remember to extract in order to check the correct file-size, the .zip is COMPRESSED so it will be smaller. You must use the extracted file anyway, not the .zip 4) Open FCEUX, go to "Config" and click "Directories...", hit the Browse button next to FDS Bios Rom, choose the folder you made. 5) NOW you will be able to open your FDS game rom and it WILL WORK! IF THE LINK TO DISKSYS.ROM ( 8 Kb ) ENDS UP BROKEN ONE DAY, CONTACT ME AND I WILL RE-UPLOAD IT RIGHT AWAY!!!!! GO HERE TO GET YOUR FDS GAME ROMS http://www.emuparadise.me/Nintendo_Famicom_Disk_System_ROMs/29 REMEMBER THE BIOS THEY HAVE THERE IS NOT THE CORRECT ONE. USE THE LINK IN STEP 2!!