The BV20 Bill Validator is a compact, exceptional value validator ideal for the amusment and vending industry. The Smiley Bill Validator / Note Reader BV20 is a compact note-validating machine, suitable for Amusement Machines, such as, kiddie rides, video games, pool tables or Low Value Vending Machines, such as, hot/cold drinks, medical items ...
There was a hack to make $5 bills get credited as $100 bills. It was on the JCM WBA-22/23 bill validator model used in slot machines. You needed a small screwdriver a wire and a battery. Stick it between the door bezel and under the BV then short two pins and insert the $5 bill. All while avoiding surveillance of course.