MAMEWorld Forums - EmuChat - Centipede/millipede trackball setup

Hey all, first post here. I just got my hands on an x-arcade tankstick with trackball. I'm running MAME OSX. It works awesome, save for the trackball. I managed to get it up and running on Blasteroids to rotate my ship (just left and right as a spinner.) That was easy to set up. The game specific setup list of centipede/millipede seems a great deal more complicated. Frankly I'm lost, I tried a few different things starting with simply wheeling up, down, etc. to specify direction but that hasn't gotten me anywhere. I've also tried messing with the other options on there referring to x and y axis. I've established that it does work on other games. Just can't get it running here. Any help anyone has to offer would be greatly appreciated.