The HP-80 was introduced for financial users following the success of the HP-35 among scientific and technical users. It has the same physical design as the HP-35, and, like early HP-35s, early HP-80s do not have a model number on their label, only the words "HEWLETT-PACKARD".

The HP-80 was the first HP calculator with business functions including the command row "n i PMT PV FV" below the display. It also had date arithmetic, bond and depreciation calculations, statistics functions including E+ and E-, and control of the display mode. It had a shift key to allow 11 extra functions to be placed on shifted keys.

The ENTER key was labelled SAVE - to avoid confusing business users! It had registers designed for use for specific business and statistics functions, but it also had STO and RCL buttons which allowed the user to store and recall numbers directly to and from a separate register.

The x^y function of the HP-35 was replaced by y^x. Thus the HP-80 introduced many of the features which have since become standard on both
scientific and business handheld calculators made by HP. The HP-80 is not particularly rare, but is of interest to collectors because it is HP's first business handheld.

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.