In Emulators / NES ROMs

How can I convert FDS into NES files, so that I can play them on emulators who aren't able to play FDS files? Is there any program that does it?

i don't understand why you don't just use FCE Ultra, and use the disk. sys file or whatever it is in the wherever you put it file.

I always love such answers. Does anybody else have a real suggestion?

He's right. Find a rom called disksys.rom, then put it in the FCE Ultra directory. To run the disk system game NES ROMs, you have to do "side-switching" like the real thing. If the game says put it on side B, do that via the function keys. Look at your file that came with FCE Ultra that should be called something like fceultra.html. That will tell you what function keys do what.

I know how to play FDS files, thanks. The unofficial NESter (with the huge mapper support) is for example able to do it. But I'm nevertheless curious.
There is a "Super Mario Bros. 2 (J)" hack as an NES file and it seems to me that it was not just made with a simple "Super Mario Bros. 1" file and a level editor, but is based on the original FDS file instead. So, how did they do it?

Well, I'm not sure then. I've never seen/heard of a FDS -> NES converter. If one does in fact exist, perhaps it was something someone created and never released it. You might try asking at the . They would probably know the answer to that.