Quick demo of fully-modded Stern “Trident” pinball with new rules and sound

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:

How to make a test bench rig for Bally-18/35 MPU boards using a PC power supply

I found this old video the other day and realized I didn’t have a post on my main site showcasing this video so I wanted to add it (also, this was before I learned the proper pronunciation of “Bally” LOL…. bah-lee).

How to add a switched power outlet to your pinball machine

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.

Pinball Feature: Custom Side Art Blades

This is a neat way to add extra art and visual appeal to your pinball machine using what are called side art blades. This is an area where many third party artists & entrepreneurs are finding clever and creative ways to mod pinball machines to increase their value and appeal. I talk about this and show you some examples.


Prototyping A Brand New Mata Hari Ruleset!

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

How to replace or repair EM pinball latch relay parts/articulating arm/rollers

Ok, that’s a mouthful huh? This is a continuation of a previous series of videos I’ve done on fixing deep ruleset issues in EM games, and now that we’ve found what’s wrong, let’s fix it!

First, here’s a video on how to replace the latch relay – there’s another post where I demonstrate how to remove the backplane from the game so it’s easier to work on.

And in this next video, if you don’t have a replacement part, I show how with a little ingenuity and a #4 tap, you can fabricate your own roller for the articulating arm.

Now that it’s fixed… let’s see how the game plays!

Fixing Shooter Lane Problems in Stern Jurassic Park pinball

This is a common issue with Stern’s Jurassic Park pinball machine. The shooter lane throws the ball into a vertical up-ramp delivering it to the right flipper, but in some cases it doesn’t reliably do so and it messes up the skill shots. Here’s a fix that is based on what appears to be a manufacturing defect with the playfields.