King of Fighters - Maximum Impact

[CatchFiveBats]

So do you need a PS1 memory card or can you just use a PS2 memory card?

Whoops!  I meant to say "PS1 Memory Card."  You can store PS1 save files on a PS2 memory card by transferring them, but you can't save PS1 games directly to a PS2 memory card and vice versa.  And PS2 files won't even fit on a PS1 memory card, so don't even try that.