It’s been quite a while since I wrote about the main game board. My last posting mentioned that I was going to install a code upgrade and a non-volatile SRAM chip to make this machine preserve high-scores after being powered off. I did actually complete this upgrade about 5 years ago and didn’t post anything about it. It was a lot fun too! I bought a EPROM programmer from eBay for about $50 and figured out how to use it. Then, I bought the two chips I needed, programmed, and finally installed them into the sockets on the game board. I remember the first power-up with the new chips resulted in a garbled display. I powered it off and was about to pull the new chips to test them. For whatever reason, I decided to power it on again and to my surprise it worked perfectly from there on. I guess the first power-up was some sort of initialization of the memory chip or something. Anyway, high scores are now able to be saved and I’ve been quite happy about it. I recall the SRAM chip has roughly a 10-year lifespan which is pretty decent considering how small it is. I don’t recall the data size it can hold, but I believe it was 12KB. (probably 11.9KB larger than it needed to be)
Why bring this up now? Well, partly to trumpet the progress I made but also to mention my recent change in direction with this cabinet. Since I fixed the original power supply issue and returned it to playability, my goal has been keeping the cabinet as close to original as possible while fixing up any cosmetic issues. That’s still the goal, but I recently decided it’s OK to expand upon the usefulness of the 4-way leaf-switched joystick and vertically-oriented monitor by adding some new games to the cabinet—as long as it is done cleanly, tastefully and is able to be completely reversed with minimal effort.
I already own a few dedicated MAME cabinets and I’m not aiming to turn this into another one. In fact, I’m not even going to mess with the original wiring in the cabinet. The only thing I’m going to add is a selectable game menu upon start-up. It will be along the same lines as what Jeff Hanson did with his Super Pac-Man. The only games will be a small selection of classics that were built for this sort of cabinet. (i.e. Pac-Man, Ms. Pac-Man, Super Pac-Man, Galaga, Donkey Kong, Dig Dug, etc.)
How is this possible without fully MAME‘ing the cabinet? Simple—I’ll build a custom JAMMA harness to interface with the original cabinet connectors and add a Programmable Multi-Game JAMMA PCB. I’ll be able to unplug the original game board and plug the new board in using the exact same connectors. Very clean and very easy to reverse. More details on what this will look like are on their way…