I am building a bartop that will most likely use a modded xbox for the engine. Glad to know the older, bigger, xbox controllers are moddable. I am thinking I will do it like I used to do game pad's alongtime ago. Set the left joystick to the digital pad, wire up the A B X Y Black White buttons, then wire the right joystick in parallel using the A B X Y buttons. That way I only hack up one controller. Who knows, just now putting the silly thing together. Like the start you have on yours, glad to know it controls well when its done. Were you playing Mame on the Xbox or one of the Arcade Ported Original Games?
Zeosstud