Atm machine founder? | And her 4 digit secret |

 Do you know? Why only 4 digit pin is used in ATM machine?

          Friends,you may have used an ATM machine at some point in your life,but do you know who it's founder is? Let me tell you it's founder is john shepherd barron,but this invention is a very interesting fact when this person invented the ATM machine he had a 6 digit pin set of ATM but his wife never remembers the 6 digit pin out of those 6 they only rememberd the 4 digit pin because of this,jhon barron set a 4 digit pin in the ATM machine and for the same reason we can choose a 4 digit pin