HP Calculator History - The HP-70

by Wlodek Mier-Jedrzejowicz Ph.D.


Introduced on August 1 1973, this was the fifth handheld electronic calculator sold by HP, and the second business model. To be specific, the first one - the HP-80 - was called a "financial" calculator
whereas the HP-70 was called a "business" calculator. In practice this meant that the HP-70 had fewer functions than the HP-80, and was $120
cheaper than the HP-80 had been when introduced.

The HP-70 does have some innovations - for example there is a key for display setting control - the display settings could be controlled on the HP-80 too, but there was no key specially for this purpose. The double-width key is now called ENTER, not SAVE as on the HP-80. There is a memory register for accumulating values - this is the first (and only?) HP handheld with an M+ button. There is a second register, which contains the number 12 when the HP-70 is turned on - for use in calculations for a fixed number of intervals - usually 12 months in a year.

These changes, and the manual which contains lots of example calculations, and even the codename "Scrooge" suggest that the HP-70 was introduced as a cheaper business model to fight competitors. It is not clear how successful this was - the HP-70 is somewhat rare!


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.