Quoted from RatShack:This Bally MPU board looks interesting, with J5 exposing the CPU bus.
I'm going to attempt to do the same thing as this, using the APC in USB mode as a bridge to MPF. A few legs broke off my 6800 when reseating chips so step #1 is already completed.
https://pinside.com/pinball/forum/topic/replacing-the-m6800-in-a-stern-mpu100-with-an-arduino
It actually works really well! Have it setup for Meteor and it is nice to be able to run the original native code or put the original MPU to sleep and let the Arduino drive. Quite a few other Bally and Stern games are already done. I am going to use it for Elektra and one other project.