HP-42S
Encyclopedia
The HP-42S 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.
series, and is designed to be compatible with all programs written for the HP-41. However, it has received criticism for its lack of expandability, and lack of any real I/O
ability, both key features of the HP-41 series.
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. Additionally, it features a two-line dot matrix display, which made stack manipulation easier to understand.
Production of the 42S ended in 1995, due at least in part to the substantial increase in the production cost of the CPU chip. In the HP calculator community, the 42S is infamous for its inflated prices in online auctions, the rare new-in-box calculators typically command in excess of $400 USD. This is nearly a four-fold increase in price over its introduction cost and has created a scarcity for utility end users. Yet, this calculator is often regarded as the best ever made in terms of quality, key stroke feel, ease of programming, and daily usability for engineers. Many scientists and engineers use this calculator today, 20 years after its introduction.
, 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.
Reverse Polish notation
Reverse Polish notation is a mathematical notation wherein every operator follows all of its operands, in contrast to Polish notation, which puts the operator in the prefix position. It is also known as Postfix notation and is parenthesis-free as long as operator arities are fixed...
Scientific hand held calculator introduced by Hewlett Packard in 1988. It has advanced functions suitable for applications in mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
, linear algebra
Linear algebra
Linear algebra is a branch of mathematics that studies vector spaces, also called linear spaces, along with linear functions that input one vector and output another. Such functions are called linear maps and can be represented by matrices if a basis is given. Thus matrix theory is often...
, statistical analysis, computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
and others.
HP-41 replacement
The HP-42S was released as a replacement for the aging HP-41HP-41
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...
series, and is designed to be compatible with all programs written for the HP-41. However, it has received criticism for its lack of expandability, and lack of any real I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
ability, both key features of the HP-41 series.
The 42S, however, has a much smaller form factor than the 41, and features many more built-in functions, such as a matrix
Matrix (mathematics)
In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...
editor, complex number
Complex number
A complex number is a number consisting of a real part and an imaginary part. Complex numbers extend the idea of the one-dimensional number line to the two-dimensional complex plane by using the number line for the real part and adding a vertical axis to plot the imaginary part...
support, an equation solver, user-defined menus, and basic graphing capabilities. Additionally, it features a two-line dot matrix display, which made stack manipulation easier to understand.
Production of the 42S ended in 1995, due at least in part to the substantial increase in the production cost of the CPU chip. In the HP calculator community, the 42S is infamous for its inflated prices in online auctions, the rare new-in-box calculators typically command in excess of $400 USD. This is nearly a four-fold increase in price over its introduction cost and has created a scarcity for utility end users. Yet, this calculator is often regarded as the best ever made in terms of quality, key stroke feel, ease of programming, and daily usability for engineers. Many scientists and engineers use this calculator today, 20 years after its introduction.
HP-42S specifications
- Series: Pioneer
- Code Name: Davinci
- Introduction: 10-31-1988
- 64 KBKilobyteThe kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...
of ROMRead-only memoryRead-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only... - Functions: Over 600
- Expandability: Officially no other than IR printing (32K memory upgrade and over-clocking hardware hacks are possible)
- Peripherals: HP-82240B Infrared Printer
HP-42S features
- All basic scientific functionsFunction (mathematics)In mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...
(including hyperbolic functions) - StatisticsStatisticsStatistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
(including curve fittingCurve fittingCurve fitting is the process of constructing a curve, or mathematical function, that has the best fit to a series of data points, possibly subject to constraints. Curve fitting can involve either interpolation, where an exact fit to the data is required, or smoothing, in which a "smooth" function...
and forecastingForecastingForecasting is the process of making statements about events whose actual outcomes have not yet been observed. A commonplace example might be estimation for some variable of interest at some specified future date. Prediction is a similar, but more general term...
) - ProbabilityProbabilityProbability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...
(including factorialFactorialIn mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n...
, random numbers and Gamma functionGamma functionIn mathematics, the gamma function is an extension of the factorial function, with its argument shifted down by 1, to real and complex numbers...
) - Equation solver (root finder) that can solve for any variable in an equation
- Numerical integrationNumerical integrationIn numerical analysis, numerical integration constitutes a broad family of algorithms for calculating the numerical value of a definite integral, and by extension, the term is also sometimes used to describe the numerical solution of differential equations. This article focuses on calculation of...
for calculating definite integrals - MatrixMatrix (mathematics)In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...
operations (including a Matrix Editor, dot productDot productIn mathematics, the dot product or scalar product is an algebraic operation that takes two equal-length sequences of numbers and returns a single number obtained by multiplying corresponding entries and then summing those products...
, cross productCross productIn mathematics, the cross product, vector product, or Gibbs vector product is a binary operation on two vectors in three-dimensional space. It results in a vector which is perpendicular to both of the vectors being multiplied and normal to the plane containing them...
and solver for simultaneous linear equations) - Complex numbers (including polar coordinates representation)
- VectorVector (mathematics and physics)In mathematics and physics, a vector is an element of a vector space. If n is a non negative integer and K is either the field of the real numbers or the field of the complex number, then K^n is naturally endowed with a structure of vector space, where K^n is the set of the ordered sequences of n...
functions - Named variablesVariable (programming)In computer programming, a variable is a symbolic name given to some known or unknown quantity or information, for the purpose of allowing the name to be used independently of the information it represents...
, registersHardware registerIn digital electronics, especially computing, a hardware register stores bits of information, in a way that all the bits can be written to or read out simultaneously.The hardware registers inside a central processing unit are called processor registers....
and binary flags - Graphic display with graphics functions and adjustable contrast
- MenusMenu (computing)In computing and telecommunications, a menu is a list of commands presented to an operator by a computer or communications system. A menu is used in contrast to a command-line interface, where instructions to the computer are given in the form of commands .Choices given from a menu may be selected...
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 beeperBuzzerA buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical, or piezoelectric. Typical uses of buzzers and beepers include alarm devices, timers and confirmation of user input such as a mouse click or keystroke....
) - Base conversion, integer arithmetic and binary and logic manipulation of numbers in BinaryBinary numeral systemThe binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...
, octalOctalThe octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...
, decimalDecimalThe decimal numeral system has ten as its base. It is the numerical base most widely used by modern civilizations....
and hexadecimalHexadecimalIn mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
systems - Catalogs for reviewing and using items stored in memory
- Programmability (keystroke programming with branchingBranch (computer science)A branch is sequence of code in a computer program which is conditionally executed depending on whether the flow of control is altered or not . The term can be used when referring to programs in high level languages as well as program written in machine code or assembly language...
, loops, tests and flags) - The ability to run programs written for the HP-41C series of calculators
Programming
The HP-42S is keystroke-programmableKeystroke programmable
Keystroke programming describes a specific way of programming by which each keystrokes on a device or application is recorded in some way and then played back so that the recorded key-presses can be repeated multiple times...
, 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
Focal
Focal may refer to:*Focal , an Irish lexicographical website*FOCAL **FOCAL-69**Focal *Focal Radio, a radio station based in Stoke-on-Trent, England-See also:*Focus...
language.
The HP-42S supports indirect addressing with which it is possible to implement a Universal Turing machine
Universal Turing machine
In computer science, a universal Turing machine is a Turing machine that can simulate an arbitrary Turing machine on arbitrary input. The universal machine essentially achieves this by reading both the description of the machine to be simulated as well as the input thereof from its own tape. Alan...
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. The program consumes 18 bytes.| Step | Instruction | Comment |
|---|---|---|
| 01 | Start of program "FAC" | |
| 02 | Store X in register 0 | |
| 03 | Store 1 in X | |
| 04 | Define label 00 | |
| 05 | Recall register 0 and multiply with X | |
| 06 | Decrement register 0 and if not zero ... | |
| 07 | ... go back to label 00 | |
| 08 | End program - result displayed in X |