IT MAY have been a humble beginning but the invention bundled onto a trolley in Glasgow’s Central Station went on to revolutionise the banking industry and make life easier for millions of people.

On May 2, 1966, James Goodfellow patented his design for personal identification number (PIN) technology and 50 years later there are three million cash-withdrawal machines worldwide.

Back living in his Paisley birthplace, Goodfellow has recalled his “eureka” moment to mark the 50th anniversary of the patent he made while working as a young engineer in Glasgow.

Yet while it is used by millions of people around the world every day and eventually gained Goodfellow an OBE, an induction into the Hall of Fame at Harvard University in the US and an honorary doctorate from the University of the West of Scotland, he made only $15 from the invention – a pittance compared with the banker bonuses of today or the £33 billion Mark Zuckerberg has made from Facebook.

He is not bitter, however, and says his brainwave was just part of his job for Glasgow firm Kelvin Hughes.

“The banks wanted an automatic cash dispenser – something that would provide a service 24/7 unmanned,” he recalls.

“They wanted a methodology for allowing access to cash on this unmanned basis. It eventually landed on my desk and the reason probably was that in 1964 I had spent some time in the United States designing access control systems.

“I was left with this problem – the demand was a million customers, 2,000 machines scattered throughout the UK which anyone could use at any time, and only money dispensed to a recognised person.

“The conventional view at the time was that it was going to be biometrics – such as your fingerprint – but that was totally impractical for many reasons.” He adds: “The actual sort of eureka moment took place when I was messing around and suddenly realised that I could do it and it would probably solve the problem.

“That took place in my head and then on an engineering model but there was quite a bit of work to put it together in demonstration form.

"I bundled this great thing on to a trolley at Central Station and wheeled it down and took it off at Euston, put it in a taxi and set it up in a boardroom and then the great and the good of the banks and the insurance companies were given the demonstration.

“We now had a token identified to a person, issued by the bank, along with a number they had to keep secret and that was the personal identification number. If you got it right then you got the money – which is exactly the same as what happens today.”

While an Englishman called John Shepherd-Barron claimed to be the inventor of the ATM, even though his machine was installed 14 months after Goodfellow’s patent was lodged, the UK Government has now officially recognised Goodfellow’s achievement in a new edition of a guidebook to life in the UK.

Under the heading “great British inventions of the 20th century” the book states: “In the 1960s, James Goodfellow (1937-) invented the cash-dispensing automatic teller machine (ATM) or ‘cashpoint’.”

After the invention, the married father-of-one went on to work for computer giant IBM for 26 years.

He is no longer sure what he did with the $15 but thinks he may have spent it on a night out.

“The remuneration was $15. I had to make patent applications for 15 countries, and the standard fee for a patent signature was $1. It didn’t change my life.”

However, he added: “I was very happy doing the job I was doing.”