You can google (CAREFUL) the roms for 1 to 6. As for ones for the psx, well, you have to download a psx emulator that lets you play the real games on your PC.

So, you can download the nes and snes roms off the internet, but you need the actual CD's to play the playstation ones on your computer. Anybody else here play IX on their computer?

Or, you could get the PC version of VII and VIII legally. I don't like those versions, though. I think all the games are better on whatever their original consoles were.