I've just picked up a 1977 Stern Stingray from a guy who has never had it running, and it came with the house he bought. The MPU and Display driver boards were in the bottom of the cabinet and seem complete except some minor battery damage and missing U2 and U6. I'm still deciding whether or not to buy the missing roms and try to get it going, or just get an Alltek board.
It also has a board in it that I've never seen before called MAA-100 and I can't find ANYTHING anywhere on the internet about what this board is. There is no sound board at all so I'm guessing this board runs the chimes? Do I possibly have something kind of rare here since I cannot find any info about it anywhere other than the documentation that came with the game saying this game is equipped with a MAA-100 board. It doesn't tell me anything more than that and there are no schematics for it. It plugs into the 32 pin connector at the top of the MPU.
Has anyone seen this board before? Here's some pics, thanks.