First ATM machine

Jhon shephered barron created the world’s first AUTOMATED TELLER MACHINE (ATM).it was installed in branch of Barclays in Enfield, north London, on July 25,1967. one by product of inventing the first cash machine was the concept of pin number. And he came with an idea, when he realized that he was able to remember his six figure army number.
But he wanted to be sure whether other’s can also do the same…so he checked it with his wife.caroline..”And it seems over the kitchen table she said she could only remember four figures, so it’s because of her, four figures became world standard.”