The Open Pinball Project is a cooperative effort to develop open source pinball hardware and software. Their stated goal is to “to build the perfect pinball machine, or at least a pinball machine for a reasonable price!” To date they’ve worked at restoring a number of old machines, learning valuable lessons in the process. Their project will consist of the development of embedded code for solenoid drivers, input switches, and main controller, and will eventually include software for running the monitor/video in the back box. They’ve explored a number of topics including display selection, construction of an EEPROM burner from scratch, building solenoid driver boards, and lately using Xilinx Spartan 3A FPGAs for solenoid driving, lighting, and digital inputs.
While this is a work in progress (no code or schematic available yet) their postings details substantial progress in the last year. This may be a project to watch for the growing number of hobbyists discovering/rediscovering pinball. Check out their blog page to follow along. Their code repository will eventually appear on Google code.</A.