HP-42S / Free42 Manual
Version 0.7.1 ─ January 2010
Author: José Lauro Strapasson, Brazil
as Open Office Writer Document surf to http://tiny.emuwiki.com/evh6
With contributions by Russ Jones, Manhattan Beach, California
Copyright (C) 2010 José Lauro Strapasson.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the section entitled "GNU Free Documentation License".
For more information visit the Free Software Foundation at http://www.fsf.org
HP-42S / Free42 Manual 1
1 Introduction 4
2 Basic Operations 5
2.1 RPN 5
2.2 Turn ON/OFF 6
2.3 Setting the display contrast 6
2.4 Training RPN using HP-42S 6
2.5 Menus 6
2.6 DISP Menu (“softkey”) 6
2.6.1 The FIX function 7
2.6.2 The ALL function 7
2.6.3 The SCI function 7
2.6.4 The ENG function 7
2.6.5 RDX. And RDX, functions 8
2.7 MODES Menu 9
2.8 The Stack 10
2.9 Getting used to some keys of the keyboard 11
3 Memory 13
3.1 The CATALOG menu 14
3.2 More on the CLEAR menu 14
3.3 The CUSTOM menu 14
4 Probability 16
5 Complex Numbers 18
5.1 Complex numbers in rectangular coordinates. 18
5.2 Complex numbers in polar coordinates 18
6 Programming 18
6.1 Basic programming 18
6.2 More than one program in the memory 20
6.3 The X?0 and X?Y sub-menus 21
6.4 Real program examples 22
7 Using the Solver 24
8 Numeric Integration 26
9 Statistics 27
9.1 The sub-menu CFIT 27
9.2 The second line: ALLΣ, LINΣ, ΣREG and ΣRG? Functions 28
10 Matrices 29
11 Other Number Bases 32
12 Flags 33
13. Features specific to “free-42” 33
13.1 Keyboard Interface (Windows, Linux and Mac Desktops and Laptops) 33
13.2 Program Import and Export 34
13.3 Printing 34
14. Comprehensive Command List 35
15 suggested reading 43
16.1 (nonprinting text below ! click VIEW / hidden paragraphs to view it in Open Office) 44
17 GNU Free Documentation License 45
Since HP-42S was a very nice calculator, and its official manual is no longer freely available and there were many people looking for its manual, seemed good to me to write my own HP-42S manual. I personally don't have a HP-42S (more than US$300 on ebay). I have a HP-33S and had a HP-48G, but my brother has one and I also use Free42 simulator for PalmOS. This manual will be of interest to people who:
Have a HP-42S calculator and lost its manual.
Got the Free42 simulator and want to know how to use it.
Have a palmtop with PalmOS and want a nice scientific calculator (get Free42)
Just want to have an idea how 42S was.
Have the official manual but don't want to read more than 300 pages!
Why HP-42S? Because it was a very, very nice calculator and also a powerful one. I know some other HP models from the past and the present like 48G, 49G, 28S, 33S, 20S, 6S Solar, 15C, and even a TI-36X Solar, etc, but 42S is my favorite. And because there is a free simulator (Free42) that works on Palm OS, Windows and Linux and there are also some emulators (at the moment emulators are only useful for who has a real calculator since HP-42S roms are not freely available). This calculator played an unique position among HP calculators! Being a scientific programmable 100% RPN calculator, it also had some graphing abilities but was pocketed sized and non RPL (some people as me like RPN, but dislike RPL). It is important to say that this manual is not complete and I don't want it to be. Two things I really don't want to see here are PRINTING and HP-41 compatibility. This because I suppose most owners don't have the printer (and it is not so useful) and also haven't had a HP-41 prior to HP-42S. If you want to download the fantastic Thomas Okken Free42 program please go to this web site http://home.planet.nl/~demun000/thomas_projects/free42/
In my opinion Free42 is even better than the real HP-42S. Try asin(acos(atan(tan(cos(sin(6°))))))
For more information about HP-42S please see
Here you can find emulators for HP-42S
http://privat.swol.de/ChristophGiesselink (very nice) http://www.geocities.com/hrastprogrammer/HP42X/index.htm
I would like to finish this introduction saying that it would be nice to have the HP-42S back to life again and even better to have a model (both real and in simulator/emulator form) based on HP-42S but with some of the 33S features like more memory, an equation editor, fractions, program lines starting with letters, physical constants, units conversion, less useless functions, etc. And it also would be nice to have HP-42S ROM images for free just like what happened to HP-48G and other models and keeping PDF versions of the manuals of retired models to download would be nice too. Perhaps someone will listen to me!
A quick note on notation: throughout this manual, for the most part, keys that are to be pressed are denoted by putting them in a box, e.g. ENTER, except when the keys are numbers or arithmetic operators. Keys that are “2nd functions” denoted by orange lettering on the calculator are denoted in orange with an orange box preceding it, e.g. ALPHA.. Functions that are accessed through the menus are generally denoted by shading in grey, such as in FCN.