The 6820 PIA (Peripheral Interface Adapter) chips are how the M6800 talks to the outside world.

The Stern MPU-100 is identical to the Bally AS-2518-17 board. At least I think it is. I’ve worked on both…

Installing new code on your machine is relatively cheap & easy. There are plug-and-play and DIY approaches available. You can write your own software too if there’s no new code available for your machine.

This project began with a need to fix an old Stern Stars. Once it was playable, the real work began.

Trident is a great game. Trident with 4-ball multiball is insanity …

After repairing a Stars machine (Stern, 1978), I started thinking about how I could improve the rules of the game. Stars is fun, but …

The games I’ve worked on have five 6-digit displays. There are four player displays and one for credits/ball-in-play. These …