>>> Err, have you ever played a NES rom in your computer?..
whatever, first download that attachment, unzip it and then..
BTW, for those who dont know, if you want to play this you have to patch the ips file to a normal ff1 rom, there are various programs to do this i used "Lunar IPS (LIPS)".
I tested this hack with RocknesX. some screens.

get the ips application here
FuSoYa's Niche - Lunar IPS (LIPS) - IPS Tool
get some nintendo emulator here
Nintendo - NES Emulators - Zophar's Domain

The ff1 rom, well is better if you look for that one yourself..