In this video designer Stephen Silver shows us the inner workings of the P3 system. It’s a very interesting and efficient design that makes the game surprisingly easy to service, with lots of features not found in typical pinball machines.
This is an introduction to an up-and-coming technology that a small group of pinball and electronics enthusiasts are developing. A custom microcontroller that interfaces with Bally-35 MPUs and allows you to write customized rulesets, even completely re-theming games. This is the first part of a journey that I hope to take everybody on.
NOTE: This is a video I recorded several months ago that I forgot to make public, so I’m much further along.. But thought it might be interesting to show this early look at the development of this technology. Now there are etched boards that can be acquired.
After getting my Trident operational, I installed the BSOS system and have been working on fine-tuning the custom code and sounds. Here’s a short demo of what the new Arduino-based controller does to a standard Bally 18/35/Stern early solid state game.
Resources (courtesy Dick Hamill):
The code is all available on GitHub. It’s broken down into a base library and then machine-specific implementations. Rewriting other games requires a moderate knowledge of C/C++.
Here’s a suggested parts list. If you bought all these things, you could create 6 of these boards. If you don’t need that many boards, you might find cheaper ways to source smaller quantities. I haven’t done any work to figure out if this is the cheapest way to source any of this stuff.
Cheap Arduino knockoff x6 ($20.99) – needs CH340 driver for programming / has to be ATmega328P
0.1″ 40-pin connector (40 pieces for $7.99)
32-pin Prototype PCB (2 pack for $9.99) – this won’t work for Alltek or MPU-200 because they have a 34-pin connector
Wire ($7.99) – tons of wire
74125 – ($1.95) https://www.jameco.com/z/74125-Major-Brands-IC-74125-Quad-Tri-State-Bus-Buffer_49373.html
Boot switch – x2 ($8.99) this switch will work for activating the Arduino board and toggling the speaker (see the writeup here to find out why: https://ballysternos.github.io/install.html)
@RoyGBev has created a PCB and kit (doesn’t include the Arduino) here:
These days modding games is all the rage: adding fancy toppers, custom lighting, subwoofers and powered speakers and more. But many pinball machines don’t have a facility for you to plug in extra stuff in your game. Many games do have a “service outlet” inside the game, but this is what’s called “un-switched” meaning it’s on all the time – mainly so technicians can use a soldering iron on the game with the power off. In this video I go over the process to tap into the switched power lines of the game to add your own extra outlet(s) that come on when you turn the game on.
I’ve been working on a new project that I’m very excited about. There’s been a movement to create an inexpensive, non-destructive and simple way to mod early Bally/Stern solid state games and add more features. In this video, I demonstrate an early prototype of the system used to modify a Bally Mata Hari pinball machine to include new features such as a skill shot, modes and even a wizard mode.
Want to learn more about this project? Visit: https://github.com/BallySternOS
As part of the ongoing restoration of a 1979 Stern “Trident” pinball machine, here’s a series of videos outlining how to replace the rectifier board on these games. This varies a bit between Stern and Bally due to wire color codes. References are here.
This is a short video demonstrating a pinball head back cover I made with a piece of 3/8″ plywood. Very easy to make, and what I like about it, is the wood actually makes the sounds of bells in the head sound a little warmer and less loud, which I think works well in home environments.