Pinball Refresh is the place to find various open source projects designed to upgrade older pinball machines with new rules and features.
Trident 2022 - with Multiball
Stars 2021
Supersonic 2022
Galaxy 2021
Instructions on how to source parts and solder them together to make your own RPU board for cheap.
A list of all the reasons you might not be getting sounds, and the ways you can fix those issues.
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.
PinballIndex.com - wiki for information on the software/hardware library
GitHub/RetroPinUpgrade - software repository for new code.
YouTube - PinballRefresh playlist
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.