HP -65 calculator
Six years after the launch of the HP 9100A computer, all its capabilities had been engineered into the HP-65 – the first programmable calculator designed to fit into a shirt pocket (hence the tapered form). It used magnetic strips to write, store and load programs and the multiple functions on each button gave the user almost immediate access to a multitude of operations.
Hewlett-Packard drew heavily on internal research and development for the HP-65. Mechanical and cognitive design studies resulted in a number of innovations: hinged keys pressing upon bent beryllium copper strips to provide a positive feel to their action; a card reader with a high level of stability ensuring reliable data writing and reading; 35 keys controlling in excess of 80 operations grouped into clusters according to their nature, with colour-coded nomenclature for multiple key-stroke operations; and key colour, size and value contrast designed to guide the user.
