BallySternOS VS pinballwizard

https://github.com/BallySternOS/BallySternOS

ballysternos is a really neat arduino project that sits on the debug header of old bally and stern mpu boards. the arduino holds the 6800 in halt from the start and re-implements game code

i've seen at least two of these in the wild, one in a Bally Eight Ball running "Eight Ball Plus" code, and another in a Stern Meteor running "Meteor 2021". both add some neat super-features and game modes, the Meteor has an accompanying wav trigger board, speakers, and amp to add wav sound effects as well -- anyone who loves Meteor will appreciate (or hate) that it no longer screams your spinner value in a high pitched tones.

Here's a similar project for old bally/stern games that might help programming wise. https://github.com/BallySternOS/BallySternOS

a lot of pinball machines are based on the 6800. i've been really impressed by one project that replaces the 6800 with an avr by just wiring up all the relevant pins and holding the 6800 in halt:

https://github.com/BallySternOS/BallySternOS

i've started working on a derivative project using an rp2040 instead of the avr with hopes of offloading the 6800 bus work to a pio

For a board, you can wire your own prototype, get a kit, or order your own PCB from Gerber files. Here are schematics and files (USE V3 FILES): https://github.com/BallySternOS/BallySternOS/tree/master/Schematics

The library that I wrote to build games on top of: https://github.com/BallySternOS/BallySternOS

Amazing, we are currently doing something very similar at our makerspace on a 1987 Road Kings pinball machine.

We first replaced the original RAM chip with a IDT 7132 SA100P dual-port RAM that sits on a breadboard:

https://pic.t0.vc/WPUO.jpg

The other port is accessed by an ATmega 1284 to the left of it. Its code responds to simple serial commands and can read and write to the RAM.

An ESP32 talks to the ATmega over UART and frequently asks it to dump 16 bytes at 0x00A0 to tell the game state and player number, and 0x0100 to get the four player scores. When it detects a new game, it offers the player a chance to scan their RFID member card and keeps track of their score:

https://pic.t0.vc/UQYK.jpg

After the game is complete, any players who have scanned in get their scores uploaded to our member portal where we can sort them by personal best:

https://pic.t0.vc/MZGY.png

We found there were sometimes read collisions and the ATmega would block the pinball machine from writing to RAM which would cause crashes or odd behavior. The latest version uses two RAM chips, one acting as a shadow copy -- similar to yours.

Eventually we'll make a PCB for it and open source everything. Currently only half the code (the ESP32) is on Github: https://github.com/Protospace/pinballwizard