Low cost 5101 Adapter
This Adapter is using a cheap PIC (which need to be programmed with the 'hex' file provided), a Diode and a capacitor, that's it!
The program use the internal RAM and EEPROM of the PIC. The capacitor and the Diode are necessary to give the PIC enough time to save the RAM Content to the EEPROM after switching of the pinball machine.
No backup battery needed anymore!
The Adapter does only work with Bally and Stern MPUs (in Bally compatibilty mode) produced between 1977 and 1985!
In case you do not have a PIC programmer I do recommend my own PIC programmer or a PICKIT3.