Pretty sure it is trying to test Capt B Zar’s head during those freezes . I’ve noticed my machine’s attract mode lights stutter ever so slightly when his head movement is tested Each time the game is first turned on. I suspect the test would time out at each stage of his head doesn’t move, or the associated switches for sensing position are broken

Your head didn’t move at all on power on. Is it broken?

Just unplugged the Capt B Zar motor on my game and power it on. It showed the exact same lengthy freezes as your video. Given that, it is safe to say those freezes can be attributed to the head not working.

Hopefully your new motor control board takes care of things.

I’ve never played with the P-5 ROM, so I don’t even know if it does a head test when first powered on. If it does, then a ROM disassembly would be necessary between the two versions to see why they behave differently. I do hardware and software professionally, so spending off hours looking at 6809 assembly doesn’t sound too fun right now

If I had to take a guess, we are dealing with an early WPC machine where the programmers were still coming up to speed on a new architecture. As such, it was easier to throw in a test that completely blocked everything while it was waiting for feedback (disabled interrupts or the kernel treated the task as high priority).

Bottom line, probably not worth the effort of investigating if you get the head moving and the issue goes away. Better use of (y)our time would be to open your favorite beverage and “blast off through the ozone”!

Very cool! Thanks for the follow up!