I have a Cabal Track Ball version that I recently converted to joystick using a Joystick Sub and joystick EPROMs that I burned. Issue seems to be P1 Start and Up don't work, with that P2 button 3. Now the button 3 and jumped to to service switch confirmed through a multi-meter.
I traced the...
This new Bios fixes the issue in Spawn. I had it in attract mode for 30 minutes without it freezing. No freezing after playing a few rounds, then back into attract. So it solved that problem for sure.