HP-42S

Last updated

HP-42S
Hewlett-Packard HP-42S, programmable calculator with RPN (combined from two images, cropped).jpg
The HP-42S
Type Programmable scientific
Manufacturer Hewlett-Packard
Introduced1988
Discontinued1995
Calculator
Entry mode RPN
Precision12 display digits (15 digits internally), [1] exponent ±499
Display type LCD dot-matrix
Display size2 lines, 22 characters, 131×16 pixels
CPU
Processor Saturn (Lewis)
Programming
Programming language(s) RPN key stroke (fully merged)
Firmware memory64 KB of ROM
Program steps7200
Interfaces
Ports IR (Infrared) printing
Other
Power supply3×1.5 V button cell batteries (Panasonic LR44, Duracell PX76A/675A or Energizer 357/303)
Weight6 oz (170 g)
Dimensions148×80×15 mm

The HP-42S RPN Scientific is a programmable RPN Scientific hand held calculator introduced by Hewlett-Packard in 1988. It has advanced functions suitable for applications in mathematics, linear algebra, statistical analysis, computer science and others.

Contents

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. [2] As this calculator is regarded amongst the best ever made in terms of quality, key stroke feel, ease of programming, and daily usability for engineers, [3] in the HP calculator community the 42S has become famous for its high prices in online auctions, up to several times its introduction price, which has created a scarcity for utility end users.

Specifications

HP-42S battery compartment and the IR diode Hp42s battery compartment.jpeg
HP-42S battery compartment and the IR diode
HP-42S calculator internal teardown HP42S Calculator Internal Teardown.jpg
HP-42S calculator internal teardown

Features

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.

The HP-42S supports indirect addressing with which it is possible to implement a Universal Turing machine and therefore the programming model of the HP-42S can be considered Turing-complete.

Sample program

This is a sample program which computes the factorial of an input integer number (ignoring the calculator's built-in factorial function). The program consumes 18 bytes. No memory registers are used.

StepInstructionComment
01LBLFACStart of program "FAC"
0211 is put into X, hence the value to be calculated upon (which was initially in X) is lifted (pushed) into stack register Y
03LBL00Define label 00
04RCL×STYRecall stack register Y and multiply with X
05DSESTYDecrement stack register Y and if not zero ...
06GTO00... go back to label 00
07END or RTNReturns control (and result in X) to either the user or to a calling program.

Legacy

An open-source software version of the HP-42S (Free42) was developed by Thomas Okken that runs on iOS, Android, Windows, MacOS, and Linux. Its source code has been released under the GNU General Public License.

In May 2017, SwissMicros released pre-production samples of an RPN calculator closely resembling the HP-42S, the DM42. The final product was released on the 9 December 2017. Even though slightly smaller (144×77×12 mm, 180 g) than the original HP-42S (148×80×15 mm, 170 g), the calculator comes with an additional top row of keys for soft menus, a keyboard layout supporting direct alpha character input, a much larger high-contrast display (Sharp low power transflective memory LCD with a resolution of 400×240, protected by Gorilla Glass) showing all four stack levels at once (configurable), ca. 75 KB usable RAM, a beeper, a callable real-time clock as well as an infrared port for HP 82240A/HP 82240B printer support and a USB interface (with Micro-B connector) emulating a FAT16-formatted USB mass storage device for easy program transfer and state backup / transfer as well as for firmware updates. The calculator, which comes in a stainless steel case with matte black physical vapor deposition (PVD) coating, supports keyboard overlays and is based on a modified version of Thomas Okken's GPLed Free42 simulator with Intel's decimal floating-point math library for higher precision (decimal128) running on an STM32L476RG processor (ARM Cortex-M4 core, 128 KB RAM, 1 MB internal flash) with another 8 MB of external QSPI flash (of which ca. 6 MB are available to users). It is powered by a CR2032 coin cell or via USB and clocked dynamically at 24–80 MHz. Since 2021, Free42 version 3 (and Plus42 version 1) optionally supports a dynamic RPN stack only limited by the amount of available memory instead of the classical four-level stack. This feature was incorporated as a selectable function into the DM42 since firmware DMCP-3.21/DM42-3.18. [6] [7]

The DM42 is also the hardware basis for the community-developed WP 43S calculator (called WP43 in more recent revisions since 2022), [8] [9] a successor to the WP 34S. The WP43 is supporting measurement system analysis (MSA) for the first time in a calculator. Expanding on the WP43 software and also based on the DM42 hardware, there are also variants with a considerable different keyboard and user interface called WP 43C (2011) / C43 (2022) / C47 (2023).

Another project based on the DM42 hardware is Christophe de Dinechin's DB48X (2022) to recreate an RPL environment from scratch.

See also

Related Research Articles

Reverse Polish notation (RPN), also known as reverse Łukasiewicz notation, Polish postfix notation or simply postfix notation, is a mathematical notation in which operators follow their operands, in contrast to prefix or Polish notation (PN), in which operators precede their operands. The notation does not need any parentheses for as long as each operator has a fixed number of operands.

<span class="mw-page-title-main">HP 48 series</span> Series of graphing calculators

The HP 48 is a series of graphing calculators designed and produced by Hewlett-Packard from 1990 until 2003. The series includes the HP 48S, HP 48SX, HP 48G, HP 48GX, and HP 48G+, the G models being expanded and improved versions of the S models. The models with an X suffix are expandable via special RAM and ROM cards. In particular, the GX models have more onboard memory than the G models. The G+ models have more onboard memory only. The SX and S models have the same amount of onboard memory.

<span class="mw-page-title-main">HP 49/50 series</span> Series of graphing calculators by Hewlett-Packard

The HP 49/50 series are Hewlett-Packard (HP) manufactured graphing calculators. They are the successors of the popular HP 48 series.

<span class="mw-page-title-main">HP-65</span> Programmable handheld calculator with magnetic card reader

The HP-65 is the first magnetic card-programmable handheld calculator. Introduced by Hewlett-Packard in 1974 at an MSRP of $795, it featured nine storage registers and room for 100 keystroke instructions. It also included a magnetic card reader/writer to save and load programs. Like all Hewlett-Packard calculators of the era and most since, the HP-65 used Reverse Polish Notation (RPN) and a four-level automatic operand stack.

RPL is a handheld calculator operating system and application programming language used on Hewlett-Packard's scientific graphing RPN calculators of the HP 28, 48, 49 and 50 series, but it is also usable on non-RPN calculators, such as the 38, 39 and 40 series. Internally, it was also utilized by the 17B, 18C, 19B and 27S.

<span class="mw-page-title-main">HP 33s</span>

The HP 33s (F2216A) was a scientific calculator marketed by Hewlett-Packard. It was introduced in 2003 as the successor to the HP 32SII, and discontinued on the introduction of its successor the HP 35s in 2007.

<span class="mw-page-title-main">HP-41C</span> Hewlett-Packard handheld RPN calculator

The HP-41C series are programmable, expandable, continuous memory handheld RPN calculators made by Hewlett-Packard from 1979 to 1990. The original model, HP-41C, was the first of its kind to offer alphanumeric display capabilities. Later came the HP-41CV and HP-41CX, offering more memory and functionality.

<span class="mw-page-title-main">HP-20S</span>

The HP-20S (F1890A) is an algebraic programmable scientific calculator produced by Hewlett-Packard from 1987 to 2000.

<span class="mw-page-title-main">HP-27S</span>

The HP-27S was a pocket calculator produced by Hewlett-Packard, introduced in 1988, and discontinued between 1990 and 1993. It was the first HP scientific calculator to use algebraic entry instead of RPN, and though it was labelled scientific, it also included features associated with specialized business calculators.

<span class="mw-page-title-main">HP calculators</span> Calculator product line by Hewlett-Packard

HP calculators are various calculators manufactured by the Hewlett-Packard company over the years.

There are various ways in which calculators interpret keystrokes. These can be categorized into two main types:

<span class="mw-page-title-main">Hewlett-Packard Voyager series</span> Programmable calculator, 1982–1984

The Hewlett-Packard Voyager series of calculators were introduced by Hewlett-Packard in 1981. All members of this series are programmable, use Reverse Polish Notation, and feature continuous memory. Nearly identical in appearance, each model provided different capabilities and was aimed at different user markets.

<span class="mw-page-title-main">HP-15C</span> Programmable scientific calculator produce by Hewlett-Packard

The HP-15C is a high-end scientific programmable calculator of Hewlett-Packard's Voyager series produced between 1982 and 1989.

<span class="mw-page-title-main">HP-16C</span> Programmable calculator produce by Hewlett-Packard

The HP-16C Computer Scientist is a programmable pocket calculator that was produced by Hewlett-Packard between 1982 and 1989. It was specifically designed for use by computer programmers, to assist in debugging. It is a member of the HP Voyager series of programmable calculators. It was the only programmer's calculator ever produced by HP, though many later HP calculators have incorporated most of the 16C's functions.

<span class="mw-page-title-main">HP-28 series</span> Series of graphing calculators produced by Hewlett-Packard

The HP-28C and HP-28S were two graphing calculators produced by Hewlett-Packard from 1986 to 1992. The HP-28C was the first handheld calculator capable of solving equations symbolically. They were replaced by the HP 48 series of calculators, which grew from the menu-driven RPL programming language interface first introduced in these HP-28 series.

<span class="mw-page-title-main">HP 35s</span> Programmable scientific calculator produced by Hewlett-Packard

The HP 35s (F2215A) is a Hewlett-Packard non-graphing programmable scientific calculator. Although it is a successor to the HP 33s, it was introduced to commemorate the 35th anniversary of the HP-35, Hewlett-Packard's first pocket calculator. HP also released a limited production anniversary edition with shiny black overlay and engraving "Celebrating 35 years".

A graphing calculator is a class of hand-held calculator that is capable of plotting graphs and solving complex functions. While there are several companies that manufacture models of graphing calculators, Hewlett-Packard is a major manufacturer.

<span class="mw-page-title-main">HP 20b</span>

The HP 20b Business Consultant is a financial calculator published in 2008 by Hewlett-Packard. Its function is similar to HP 10bII and includes scientific and statistical functions.

<span class="mw-page-title-main">HP 30b</span>

The HP 30b is a programmable financial calculator from HP which was released on 7 January 2010. The HP 30b is an advanced version of the HP's prior model HP 20b. Featuring a two line alpha numeric display, ability to input data via Reverse Polish Notation, Algebraic and normal Chain algebraic methods, and twelve digit display.

In computing FOCAL character set refers to a group of 8-bit single byte character sets introduced by Hewlett-Packard since 1979. It was used in several RPN calculators supporting the FOCAL programming language, like the HP-41C/CV/CX as well as the later HP-42S, which was introduced in 1988 and produced up to 1995. As such, it is also used by SwissMicros' DM41/L, both introduced in 2015, and is implicitly supported by the DM42, introduced in 2017.

References

  1. HP-42S RPN Scientific Calculator - Owner's Manual (PDF) (1 ed.). Corvallis, OR, USA: Hewlett-Packard Co. June 1988. p. 3. 00042-90001. Archived (PDF) from the original on 2017-09-17. Retrieved 2017-09-17.
  2. "HP-42S". Museum of HP Calculators. Retrieved 2016-10-27.
  3. "HP's best scientific calculator?".
  4. Hosoda, Takayuki (2007-10-10). "Upgrading the memory of the HP 42S to 32KB". Archived from the original on 2017-09-17. Retrieved 2011-08-12.
  5. HP 42S Easy Double Speed / Turbo Mode for Calculator and Programs , retrieved 2022-08-05
  6. https://forum.swissmicros.com/viewtopic.php?f=16&t=2939
  7. https://forum.swissmicros.com/viewtopic.php?f=15&t=2845
  8. Bonin, Walter (2019) [2015]. WP 43S Owner's Manual (PDF). 0.13 (draft ed.). ISBN   978-1-72950098-9 . Retrieved 2019-10-31. (314 pages)
  9. Bonin, Walter (2019) [2015]. WP 43S Reference Manual (PDF). 0.13 (draft ed.). ISBN   978-1-72950106-1 . Retrieved 2019-10-31. (271 pages)

Further reading