HP-42S#DM42

{{ Infobox Calculator

| name = HP-42S

| image = HP42S.jpg

| caption = HP-42S

| type = Programmable scientific

| entry = RPN

| designfirm =

| manufacturer = Hewlett-Packard

| introduced = 1988

| discontinued = 1995

| processor = Saturn (Lewis)

| precision = 12 display digits (15 digits internally), exponent ±499

| display_type = LCD dot-matrix

| display_size = 2 lines, 22 characters, 131×16 pixels

| prog_lang = RPN key stroke (fully merged)

| memory_step = 7200

| memory_rom = 64 KB of ROM

| ports = IR (Infrared) printing

| supply = 3×1.5 V button cell batteries (Panasonic LR44, Duracell PX76A/675A or Energizer 357/303)

| weight = {{convert|6|oz|g|abbr=on}}

| dimensions = 148×80×15 mm

}}

The HP-42S RPN Scientific is a programmable RPN Scientific hand held calculator introduced by Hewlett-Packard in 1988. It is a popular calculator designed for science and engineering students.

Overview

Perhaps the HP-42S was to be released as a replacement for the aging HP-41 series as it is designed to be compatible with all programs written for the HP-41. Since it lacked expandability, and lacked any real I/O ability, both key features of the HP-41 series, it was marketed as an HP-15C replacement.

The 42S, however, has a much smaller form factor than the 41, and features many more built-in functions, such as a matrix editor, complex number support, an equation solver, user-defined menus, and basic graphing capabilities (the 42S can draw graphs only by programs). Additionally, it features a two-line dot matrix display, which made stack manipulation easier to understand.

Production of the 42S ended in 1995.

Specifications

Image:Hp42s battery compartment.jpeg

File:HP42S Calculator Internal Teardown.jpg

Series: Pioneer
Code Name: Davinci
Introduction: 1988-10-31
64 KB of ROM
8 KB of RAM
Functions: Over 350
Expandability: Officially no other than IR printing (32 KB memory upgrade and over-clocking hardware{{Citation |title=HP 42S Easy Double Speed / Turbo Mode for Calculator and Programs |url=https://www.youtube.com/watch?v=fYCjhFKgHdo |language=en |access-date=2022-08-05}} hacks are possible)
Peripherals: HP 82240A infrared printer

Features

All basic scientific functions (including hyperbolic functions)
Statistics (including curve fitting and forecasting)
Probability (including factorial, random numbers and Gamma function)
Equation solver (root finder) that can solve for any variable in an equation
Numerical integration for calculating definite integrals
Matrix operations (including a matrix editor, dot product, cross product and solver for simultaneous linear equations)
Complex numbers (including polar coordinates representation)
Vector functions
Named variables, registers and binary flags
Graphic display with graphics functions and adjustable contrast
Menus with submenus and mode settings (also custom programmable) that use the bottom line of the display to label the top row of keys
Sound (piezoelectric beeper)
Base conversion, integer arithmetic and binary and logic manipulation of numbers in binary, octal, decimal and hexadecimal systems
Catalogs for reviewing and using items stored in memory
Programmability (keystroke programming with branching, loops, tests and flags)
The ability to run programs written for the HP-41C series of calculators

Programming

The HP-42S is keystroke-programmable, meaning that it can remember and later execute sequences of keystrokes to solve particular problems of interest to the user. The HP-42S uses a superset of the HP-41CX FOCAL language.

All programs are stored in one continuous program space, and may be created and edited by switching to programming mode, using the {{keypress|PRGM}} key.

Subroutines are enclosed in {{keypress|LBL}}/Label (name of subroutine) and {{keypress|RTN}}/Return ( halts execution unless it is in a subroutine in which case it returns to the caller). Keystrokes (of functions) are enclosed between {{keypress|LBL}} and {{keypress|RTN}} or {{keypress|.END}}.

In a running program, a {{keypress|GTO}}label causes program execution to branch to the specified label and continue running at that line.Executing a GTO instruction from the keyboard moves the program pointer to the corresponding label. No program lines are executed.

{{keypress|XEQ}} is used in much the same way with one important difference: after an {{keypress|XEQ}} instruction has transferred execution to the specified label, the next RTN (return) or END instruction causes the program to branch back to the instruction that immediately follows the XEQ instruction.Programs/Subroutines can also be executed with the help {{keypress|XEQ}}label (Execute) key.

Important difference is that {{keypress|XEQ}} executes the label and returns to previous subroutine and continues execution from the line following {{keypress|XEQ}},whereas {{keypress|GOTO}} branches to the label specified and doesn't return.

{{keypress|GTO}}{{keypress|.}}{{keypress|.}} packs the current subroutines and moves to new program space.{{keypress|GTO}}{{keypress|.}}nnnn can be used to reach a particular line of program.

= Programming examples=

A simple program to calculate area of circle

class=wikitable

! Step

! Instruction

! Comment

| { 6-Byte Prgm }

| {{keypress|LBL}}{{keypress|A}}{{keypress|R}}{{keypress|E}}{{keypress|A}}

| Start of program "AREA"

| {{keypress|INPUT}}{{keypress|R}}

| Prompts for Value of R and stores it in R

| {{keypress|X↑2}}

| Squares the value in X register

| {{keypress|PI}}

| Puts π on the stack

| {{keypress|×}}

| Multiplies values in X and Y register

{{keypress|END}} or {{keypress|RTN}}

| Returns control (and result in X) to either the user or to a calling program.

Program instructions like {{keypress|STOP}}, {{keypress|PROMPT}}, {{keypress|INPUT}} halt the program execution,which can be continued by pressing {{keypress|R/S}}.

{{keypress|VIEW}} is used to view contents of a register,For example R in the above example.

= Using Integral and Equation Solver =

It is necessary to write a program or subroutine that evaluates f(x) for the function which needs to be solved or integrated.

Variables used in program should be declared using {{keypress|MVAR}}

Here is a sample program to solve the equation °F = (9/5×°C) + 32

class=wikitable

! Step

! Instruction

! Comment

| { 31-Byte Prgm }

| {{keypress|LBL}}{{keypress|T}}{{keypress|E}}{{keypress|M}}{{keypress|P}}

| Start of program "TEMP"

| {{keypress|MVAR}}{{keypress|F}}

| Declares F as a variable for solver

| {{keypress|MVAR}}{{keypress|C}}

| Declares C as a variable for solver

| {{keypress|RCL}}{{keypress|F}}

| Recall F

| {{keypress|9}}

| {{keypress|5}}

| {{keypress|÷}}

| {{keypress|RCL}}{{keypress|C}}

| Recall C

| {{keypress|×}}

| {{keypress

}}

| {{keypress|3}}{{keypress|2}}

| {{keypress

}}

{{keypress|END}} or {{keypress|RTN}}

| Returns control (and result in X) to either the user or to a calling program.

After, accessing the solver using {{button|Shift}} {{keypress|7}} ({{keypress|SOLVER}} ), select program {{keypress|TEMP}}.

In a similar way, expressions can be integrated. After selecting the variable of integration, enter the lower limit and then press on {{keypress|LLIM}}, similarly input {{keypress|ULIM}} (upper limit) and {{keypress|ACC}} (accuracy).

Emulators

Image:Emu42 emulator.png

HP 42s can be accessed through Android Emulators like Emu42 and Free42.

Image:Hp30bwp34s.jpg

=WP 34s=

WP 34S project uses a modern HP financial calculator HP 30b as the starting point to create an advanced scientific RPN calculator. It is a more powerful scientific (non-graphing) calculator compared to the original HP 42s.https://commerce.hpcalc.org/34s.php

Functionality

Euler's Beta and Riemann's Zeta functions, Bernoulli and Fibonacci numbers, Lambert's W, the error function as well as Chebyshev's, Hermite's, Laguerre's and Legendre's orthogonal polynomials, and testing for primality,
Many statistical distributions and their inverses like Poisson, Binomial, Geometric as well as Cauchy-Lorentz, Exponential, Logistic, Weibull for reliability analysis, Lognormal and Gaussian with arbitrary means and standard deviations,
Programmable sums and products, first and second derivatives

Programmability

RPN keystroke programmable à la HP-41 - up to 925 steps in RAM - numeric and/or alpha labels, thousands of steps burnable into flash banks.
Externally programmable by developers via JTAG interface

Reference Books

Image:RPN Books.png

Guides and Collections of Keystroke Programs

Documentation for the HP 42S calculator at hpcalc.orghttps://literature.hpcalc.org/allhttps://literature.hpcalc.org/all#model:42S

HP-42S Owner's Manual https://literature.hpcalc.org/items/929

HP-42S Programming Examples & Techniqueshttps://literature.hpcalc.org/items/934

Step-by-Step Solutions: Electrical Engineering (42S)https://literature.hpcalc.org/items/924

Step-by-Step Solutions: Mechanical Engineering (42S)https://literature.hpcalc.org/items/927

Advanced Circuit Analysis with the HP-42Shttps://literature.hpcalc.org/items/1449

An Easy Course in Using the HP-42Shttps://literature.hpcalc.org/items/1459

Educational Texts on RPN calculators

Algorithms for RPN Calculatorshttps://literature.hpcalc.org/items/1454

Scientific Analysis on the Pocket Calculatorhttps://literature.hpcalc.org/items/1712

Engineering Statistics with a Programmable Calculatorhttps://literature.hpcalc.org/items/1533

Applied Mathematical Physics with Programmable Pocket Calculatorshttps://literature.hpcalc.org/items/1479

Mathematical Astronomy with a Pocket Calculatorhttps://literature.hpcalc.org/items/1663

Handbook of Electronic Design and Analysis Procedures using Programmable Calculatorshttps://literature.hpcalc.org/items/1558

Calculator Programs for Chemical Engineers(Vol 1 & 2)https://literature.hpcalc.org/items/1536https://literature.hpcalc.org/items/1860

Collection of Algorithms/Keystroke Programs for HP 41/HP 42S

Extensive Collection of Physics and Mathematics Programshttps://hp41programs.yolasite.com/
Software Library for HP 41 Programs(Compatible with HP 42S)https://www.hpmuseum.org/software/soft41.htm

References

{{reflist|refs=

{{cite web |title=HP-42S |url=http://www.hpmuseum.org/hp42s.htm |website=Museum of HP Calculators |access-date=2016-10-27}}

{{cite web |author-first=Takayuki |author-last=Hosoda |title=Upgrading the memory of the HP 42S to 32KB |date=2007-10-10 |url=http://www.finetune.co.jp/~lyuka/interests/calc/hp42s/ |access-date=2011-08-12 |url-status=live |archive-url=https://web.archive.org/web/20170917220206/http://www.finetune.co.jp/~lyuka/interests/calc/hp42s/ |archive-date=2017-09-17}}

}}

External links

[https://www.swissmicros.com/product/dm42 SwissMicros DM42]
[http://www.hpcc.org/datafile/V23N6/LongLiveTheHP42S.pdf HP-42S intro on hpcc.org]
[http://www.hpmuseum.org/hp42s.htm HP-42S page on hpmuseum.org]
[https://web.archive.org/web/20141217101848/http://www.hp42s.com/ HP-42S resources on hp42s.com] (defunct as of July 2017)
[http://www.rskey.org/detail.asp?manufacturer=Hewlett-Packard&model=HP-42S HP-42S description on rskey.org]
[http://www.thimet.de/CalcCollection/Calculators/HP-42S/Contents.htm HP-42S description on thimet.de]
[https://market.android.com/details?id=com.thomasokken.free42&feature=also_installed#?t=W251bGwsMSwxLDEwNCwiY29tLnRob21hc29ra2VuLmZyZWU0MiJd Free42 for Android by Thomas Okken, an Open Source project.]
{{cite web |url=http://thomasokken.com/free42 |title=Free42, A HP-42S Calculator Simulator |author-first=Thomas |author-last=Okken |date=2011-04-20 |access-date=2011-08-12}}

42S

Category:Computer-related introductions in 1988