|Precision||12 display digits (25 digits internally), exponent ±499|
|Display Type||LCD Dot-matrix|
|Display Size||2 lines, 22 characters, 131x16 pixels|
|Programming language(s)||RPN key stroke (fully merged, Turing complete)|
|Firmware Memory||64 KB of ROM|
|Ports||IR (Infrared) printing|
|Power supply||3×1.5V button cell batteries (Panasonic LR44, Duracell PX76A/675A or Energizer 357/303)|
|Weight||6 oz (170 g)|
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.
The HP-42S was released as a replacement for the aging HP-41 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. In the HP calculator community, the 42S is infamous for its high 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, 25 years after its introduction.
- Series: Pioneer
- Code Name: Davinci
- Introduction: 10-31-1988
- 64 KB of ROM
- 8 KB of RAM
- 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
- 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
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 (unrelated to the DEC FOCAL programming language).
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.
|01||LBLFAC||Start of program "FAC"|
|02||STO00||Store X in register 0|
|03||1||Store 1 in X|
|04||LBL00||Define label 00|
|05||RCL×00||Recall register 0 and multiply with X|
|06||DSE00||Decrement register 0 and if not zero ...|
|07||GTO00||... go back to label 00|
|08||RTN||End program - result displayed in X|
- HP-42S page on hpmuseum.org
- An Alternative HP-42S/Free42 Manual from educalc.net
- HP-42S resources on hp42s.com
- HP-42S description on rskey.org
- HP-42S description on thimet.de
- Free42 for Android by Thomas Okken, an Open Source project.
- Thomas Okken (2011-04-20). "Free42, A HP-42S Calculator Simulator". Retrieved 2011-08-12.
- An Alternative HP-42S/Free42 Manual
- Takayuki Hosoda (2007-10-10). "HP-42S memory upgrade and overclock". Retrieved 2011-08-12.