Bitkit

Ms Pac-Man Progress

It’s nice when a full row of games is complete enough to power on and everything is playable..

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This project Ms Pac cabaret came to me complete but not working.

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So far, I’ve recapped the monitor, changed the top CPO, added a marquee light and new T-Molding. New Buttons, rebuilt the joystick and tumbled some of the metal.

Still, plenty of rust on the door hinge and the game counter that I need to address.

The game came with a full not-really-working Ms Pac boardset and original power supply.

I cleaned the original harness, boards and power supply and wrapped and stored them for future purist endeavors. To get the game going, I decided to go FPGA instead - Bitkit to the rescue.

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Storing the original harness, PCBS and power brick in the bottom wrapped in plastic and brown-paper. I built up a power-block with a new 8-liner and isolation transformer and switched the game to a JAMMA wiring harness. I installed Ms Pac on the Bitkit and set it to directly boot to the game instead of a game selection menu.

The BitKit in action:

I still need to address rusty spots, the side laminate and the game could use a new monitor overlay.

All said though, it is running great with the Bitkit with only one caveat.

There are sync frequency differences between the Bitkit menu and the MsPac Rom.

I can get the monitor dialed in for one or the other but not both, so at this point it has little value as a multi-game, it is strictly a dedicated Ms Pac. The bitkit offers some choices for this, including reversing the polarity of the Sync through a jumper. I’m more inclined to blame this on the monitor than Bitkit, though. I’ll spend some time to determine the sync polarity and attack that problem more surgically in the near future. My guess is that I may be able to solve it with some combination of tweaks between V-Sync, h-Sync or sync-ground tweaks on the harness.

UPDATE 3/20/2019: Aaron (from Bitkit) saw this post and proactively reached out to me (because he is that kind of awesome). He confirmed that (paraphrasing him here) the Bitkit’s origins in Nibbler (Fantasy, Pioneer Balloon, Vanguard, Zarzon) so that the original menu was built with the Nibbler hardware in mind. There are some sync differences between the Nibbler hardware and the Pac hardware. He said he intends to release a future update (early May) to port the Bitkit menu system to the Pac hardware.

That said, in my case I haven’t spent a ton of time (aside from pot adjustments) experimenting with the the sync and grounds to see if I can get both the MsPac and the Bitkit menu dialed in equally. As I alluded to above the best I can do, today with the adjustment pots is to get the Bitkit menu w/ MsPac having a large g07-like curl on the right or I can get MsPac dialed in perfectly at the expense of the Bitkit sync.

I’m more inclined to believe this is an out-of-variance condition on this monitor than any real fault or weakness in Bitkit. Don’t take my report here as a strike against Bitkit - I’m extremely happy with the Bitkit board. It plays perfectly, boots fast and was super-simple to get running.

One of those situations where I triaged this to: “okay it plays great overall situation is good enough for now” and I moved on down the line to the next dark marquee in the lineup.. :)

I’m not sure about my long-term intentions having (effectively) three cabinets that will play Ms Pacman in some capacity but I’m sure this could be excellent trade bait for something else down the line, if it comes to that..