Hi All,

A few months ago I started reading Peter Henrici's book "Computational Analysis with the HP-25 Pocket Calculator". The book contains very interesting programs that implement interesting algorithms. I am impressed how, the late Swiss mathematician, Henrici was able to push the HP-25 to the very limit. I have been translating some of his programs to HP-67 and HP-41C, allowing me more breathing space and the ability to generalize Henrici's program. The code does a lot and without the advantage of using subroutines. I guess Henrici wanted to target the lower-cost HP-25 calculator--perhaps barely affordable to students. I wish he did a version for the more expensive (especially for students) HP-67 or HP-41C--a project that needed much selling to the conservative publishers.

Henrici's wife has also written a similar book for the HP-33C (which I also have) and this book is a companion of "Essentials of Numerical Analysis", also by Henrici. The HP-33C version uses subroutines and is able to explore more interesting algorithms.

Among the books written for programmable calculators, Henrici's books for the HP-25 and HP-33C stand tall. If you have spare time to fiddle with old code (and even run it on the HP-25 emulator available on this site) then I encourage you to do so. It is also an interesting journey into cool computational algorithms.

Namir