I have built a number of cp's, mame units and games (original and multis). Today for the first time, i hooked a Spintrak to the X player1 trackball input on a game elf and i figured id share my experience with anyone foolish enough to try this. Spintrak works decent enough with the buffered input from a pc mame box, but direct to game elf, right from thr box with no mods seems to be incredibly a complete waste of time. An optical trakball works better, but not great. It appears that Spintraks unbuffered input to GE multi boards lags, skips and without any mods (that arent easily done) result in useless game play. Unless im missing something, GE is not the platform to use a direct connected Spintrak to.. your milage may vary.
Lee!