I've been refurbing a fancy copy machine controller.
Since I paid $13 for it and it had $65 cash in it, the project seems to be off to a fairly good start. The main problem seemed to be a broken crimp lead on the power supply connector.
It is tricky to test if you do not have a copier to give you a "copy made" feedback signal.
The apparently industry standard CoinPro 3 mechanism and the M6000 controller (and the bill changer, copier, and reader) apparently talk to each other with simple alphanumeric serial commands.
The commands are likely 2400 baud, eight bit, no parity, one stop. One channel for send and one for receive.
Connector pinouts are readily available. Of the six pin Molex style connector, two are for supply power, one for transmit, one for receive, and one for T/R return common.
The CoinPro obviously sends stuff like "got a quarter", "got a dime", "got a nickel", "got a slug", "quarter dispenser tube above minimum", "quarter dispenser tube full", (nickel - dime- etc...)
And obviously receives stuff like "return a dime", "return a quarter", and "return a nickel".
PIC control leads to interesting possibilities for nonobvious apps.
Checking all 256 commands in both directions would be painful.
Can the "secret insider stuff" instruction set be downloaded? From where?