In 1972 the Hewlett Packard Corporation placed on the market the revolutionary HP-35 pocket scientific calculator which utilised integrated circuitry and provided output on a red LED screen. This calculator held a stack of memories to which, using the reverse polish notation method, operations could then be sequentially applied. Operations included not only addition, subtraction, multiplication and division, but a wide slate of trigonometic and other functions, including logarithms and the operations which could be utilised with them. It was a game changer and effectively brought the utility of all prior calculating machines to an end.

This collection currently holds an HP-35 and an HP-45 calculator.


  • The HP-45 in this collection was kindly donated by John Dean.


Page last modified on 28 November 2011