HP Calculator History - The HP-29C

by Wlodek Mier-Jedrzejowicz Ph.D.


A year after the introduction of three new models on July 1 1976, HP introduced three more models on July 1 1977. These models (equal 15th in the count of small calculator models made by HP) were the HP-10, HP-29C and HP-92 - three very different calculators.

The HP-29C, codenamed "Bonnie", was the last model in the Woodstock family or "Series 20". The codename bears no relation to the previous names of Series 20 models, which were all named after vegetables. In contrast, the HP-29C was followed by a printing version, the HP-19C, and these two were called Bonnie and Clyde. Or does someone know of a vegetable called Bonnie?

The HP-29C was introduced as an improved version of the HP-25C, with more memory, more program steps (98) and a few extra functions. In fact it inherited many of the features of the HP-67, such as a second set of registers and even reverse branching when a negative number was put in the "indirect" register and used by an indirect GTO command. Though a considerable improvement on the HP-25 and HP-25C, it did not quite achieve the same popularity, perhaps because the HP-67 provided keen competition.


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.