Ok, say i was building a panel to play 2-player simultaneous Marble Madness via MAME on a WinXP machine. If I used two Happ Trackballs and two Opti-wiz interfaces from Groovy Game Gear, any reason why that wouldn't work? i don't see many dual-trackball panels so I wanted to make sure before I place orders, etc.
(I really am still working on my Raiden cab, promise! Also would love to get a puzzle-game oriented cocktail done for my wife before Christmas.)
(Imagine a Joust cocktail having a very ugly baby with a Millipede cocktail... that is pretty much where i am headed.)