RPN-45 is available here:

RPN-45 HD (iPad)

RPN-45 SD (iPhone, iPod touch)



Articles on the HP-45

Using an example, this article from 1976 shows how the HP-45 computes the cosine of an angle. In German only, unfortunately, but with the help of the pictures, formulas and tables you may get the idea.

Page 1 Page 2 Page 3 Page 4

In 1976, some clever tinkerers added programmability to the HP-45. In German only.

Page 1 Page 2 Page 3 Page 4

A paper written by Hewlett-Packard in 1974, praising the virtues of RPN.

Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7

In 1976, Egbert Electronics from Orem, Utah, offered a quartz kit for the HP-45. It cost $13. Here are the installation instructions.

Page 1 Page 2 Page 3



Internet Links, Quick Reference Guide

HP-45 Quick Reference Guide
The original reference guide that came with the HP-45. This early edition contains errors on pages 5 and 6, corrected in later editions.

HP-45 Owner's Handbook
A freely available online version of the Owner's Handbook. If you're looking for a beautiful PDF version, check out the offerings of the HP Museum (see below).

HP-45 Applications Book
A wonderful written by Hewlett-Packard Advanced Products Division, giving step-by-step solutions to more than 200 problems in mathematics, statistics, finance, engineering, navigation plus tips on more efficient calculator operations.

The number one URL for all things "HP calculators". At http://www.hpmuseum.org/simulate/sim45.htm there's even a Java application simulation of an HP-45 based on the real ROM microcode.
Manuals (and much more) may be purchased here: http://www.hpmuseum.org/cd/cddesc.htm

Good article about Reverse Polish Notation.

A browser-based simulation of the HP-45, written in JavaScript. Runs fine on Firefox – Safari and Google Chrome, however, report a type error, refusing execution. Not a perfect simulation, but a good example of the power of JavaScript (http://www.t-denker.de/hp45/hp45.750.js).




HP-35 in Popular Electronics (1972)
A very early review of the HP-45's predecessor.

Copyright © 2018. All rights reserved.