HP Calculator History - The HP-21

by Wlodek Mier-Jedrzejowicz Ph.D.


Introduced on February 1 1975, just a month after the HP-55, this was the seventh handheld electronic calculator sold by HP, and the first to look different from the original HP-35 shape.

The model number showed that it was to be the first of a new family - the "series 20" or "Woodstock" series. Its code name was "Pumpkin" - it was a small, non-programmable handheld calculator with lots of scientific functions.

Its main attractions were its small size - which made it easier to fit in a pocket than the "Classic" models, and easier to use with one hand - and its low price, for those days, of $125.


This article is part of the WMJARTS file. This file contains a series of articles written by Wlodek Mier-Jedrzejowicz and published in DATAFILE, the journal of the HPCC. The article was reproduced with permission of the author.

Copyright Wlodek Mier-Jedrzejowicz Ph.D.