Recently updated my software and my son LOVES the Fred Flintstone Memory Match game.
I'd like to quickly build him a stand-alone controller for it..before the fad wears off.

For those unfamiliar with the game, it uses 9 buttons in a 3x3 grid.
The Mame default is to use the #keypad for the 9 buttons. It works but it could be better.
So any ideas on the easiest way to go about this? I'm already running a Keywiz on this machine so I'm guessing I'll have to go USB.