The NES was originally released as the Family Computer, or Famicom in Japan. It was later released as the Nintendo Entertainment System around the world. There was a Japan only disk addon for it called the Famicom Disk System.
nesh (Convenience folder for romhacks)
.nes .unif .unf .zip .7z
.fds .zip .7z
The original NES does not require a BIOS file, but a BIOS is necessary for the Famicom Disk System.