development engineer and had been asked to devise a way to enable customers to withdraw cash from banks on Saturdays. “Most people working during the week couldn’t get to the bank. They wanted a solution. The solution was a machine which would issue cash on demand to a recognized customer,” he recalls. “I set out to develop a cash-issuing machine and, to make this a reality, I invented the PIN [personal identification number] and an associated coded token.” This token took the form of a plastic card with holes punched in it. The patent documents proposed a system incorporating a card reader and buttons mounted in an external wall of the bank and stated: “When the customer wishes to withdraw a pack of banknotes from the system, he simply inserts his punched card in the card reader of the system and operates the set of ten push-buttons in accordance with his personal identification number.” Aside from the cards with punched holes, that pretty much describes today’s ATM. After Goodfellow successfully demonstrated the methodology by producing a model, prototypes were built and the first machines were installed in 1967. At around the same time, Shepherd-Barron was developing a rival cash-dispensing device. His machine didn’t use plastic cards – instead, it used cheques impregnated with carbon-14, a mildly radioactive substance. The machine detected the