Comparison (34C-59) of numerical ∫ algorithm

[Steve Simpkin]

The Aug 1980 issue of HP Journal magazine has detailed information on the Numerical Integration feature of the HP-34C (page 23). This article was written by Professor William Kahan who developed the Solve and Integration algorithms for the HP-34C. A PDF of this issue is available here:
http://hparchive.com/Journals/HPJ-1980-08.pdf

There is a really interesting story behind the development of the HP-34C. Professor William Kahan, who worked as a consultant for HP, came up with an algorithm for a numeric solver and really wanted HP to implement it in a calculator. The problem was that HP marketing had no interest in making a model with a solver. Their marketing studies convinced them that their customers did not want a calculator with a "Solve" key. Professor Kahan kept bringing this subject up with Stan Minz, the person in charge of one of the HP calculator development groups. Finally Stan said if you can create an algorithm that will fit in a calculator that solves numeric integration problems, I will incorporate your Solve function into that calculator. That is just what professor Kahan did. Even after HP committed resources to making the HP-34C, HP management did not want to fully document the new Solve/integration functionality. The full story is very entertaining as is the story behind the development of the HP-15C.

Professor Kahan's full oral history PDF document can be found at the following link. The discussion of the HP-34C starts on page 152.
https://drive.google.com/file/d/1Jlg9EWQ...zwcol/edit