HP-42S
 The HP-42S | |
| Type | Programmable scientific |
|---|---|
| Manufacturer | Hewlett Packard |
| Introduced | 1988 |
| Discontinued | 1995 |
| Calculator | |
| Entry mode | RPN |
| Precision | 12 display digits (15 digits internally),[1] exponent ±499 |
| Display type | LCD Dot-matrix |
| Display size | 2 lines, 22 characters, 131x16 pixels |
| CPU | |
| Processor | Saturn |
| Programming | |
| Programming language(s) | RPN key stroke (fully merged, Turing complete) |
| Firmware memory | 64 KB of ROM |
| Program steps | 7200 |
| Interfaces | |
| Ports | IR (Infrared) printing |
| Other | |
| Power supply | 3×1.5V button cell batteries (Panasonic LR44, Duracell PX76A/675A or Energizer 357/303) |
| Weight | 6 oz (170 g) |
| Dimensions | 148×80×15mm |
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.
HP-41 replacement
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. Additionally, it features a two-line dot matrix display, which made stack manipulation easier to understand.
Production of the 42S ended in 1995.[2] In the HP calculator community, the 42S is famous for its high prices in online auctions, with good condition calculators typically selling at around US$400 (2016) [3] 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 regarded amongst the best ever made in terms of quality, key stroke feel, ease of programming, and daily usability for engineers. [4]
HP-42S specifications
- Series: Pioneer
- Code Name: Davinci
- Introduction: 1988-10-31
- 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
HP-42S 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 (unrelated to the DEC FOCAL programming 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.
| Step | Instruction | Comment |
|---|---|---|
| 01 | LBLFAC | Start of program "FAC" |
| 02 | 1 | 1 is put into X, hence the value to be calculated upon (which was initially in X) is lifted (pushed) into stack register Y |
| 03 | LBL00 | Define label 00 |
| 04 | RCL×STY | Recall stack register Y and multiply with X |
| 05 | DSESTY | Decrement stack register Y and if not zero ... |
| 06 | GTO00 | ... go back to label 00 |
| 07 | END or RTN | Returns control (and result in X) to either the user or to a calling program. |
References
- ↑ HP-42s Owner's Manual. Corvallis, OR: Hewlett-Packard Co. 1988. p. 3.
- ↑ Museum of HP Calculators http://www.hpmuseum.org/hp42s.htm. Retrieved 27 October 2016. Missing or empty
|title=(help) - ↑ Ebay http://www.ebay.co.uk/itm/HP-42S-Hewlett-Packard-Calculator-HP-42S-/191988242232?hash=item2cb3641738:g:F3wAAOSw8gVX9Ts0
- ↑ http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv020.cgi?read=177373
External links
- HP-42S Owner's Manual on HP41.net
- HP-42S intro on hpcc.org
- HP-42S page on hpmuseum.org
- 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.