Heathkit_ET-3400 VS BallySternOS

[3] https://github.com/CalPlug/Heathkit_ET-3400

There is something special to me about the idea of writing modern C++, and compiling it for such early microprocessors. The 512 bytes of RAM is a pretty big limitation though. I wanted to try and emulate an EEPROM using an Arduino or FPGA, but got stalled out on the project. From time to time I like to browse through the LLVM backend documentation, but I can't seem to commit to trying to build a backend.

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