That is in essence right nixxy. Note changers do indeed have a train function on them to remember what note should give what value of credit when inserted. How this works to a tee i'm not sure, but something along the lines of what you've posted sounds fair enough.
As for the scam notes - don't bother unless you want to spend time at her majesty's pleasure!
"Sixty percent of the time, it works, every time!"
Dunhamzzz wrote:They look for a crocodile mouth made of plastic attached to the end of a £20 note with a 15mil strip cut off the bottom with the whole thing being attached to a 50p piece with fishing wire..
Lol - somehow I don't think everyone here will get that nehehe