The HP-42S |
|
| Type | Programmable Scientific |
|---|---|
| Manufacturer | Hewlett Packard |
| Introduced | 1988 |
| Discontinued | 1995 |
| Calculator | |
| Entry mode | RPN |
| Precision | 12 display digits (25 digits internally), 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.
Contents |
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, 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.
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.
This is a sample program which computes the factorial of an input integer number. The program consumes 18 bytes.
| Step | Instruction | Comment |
|---|---|---|
| 01 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">LBL</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">F</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">A</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">C</kbd> | Start of program "FAC" |
| 02 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">STO</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd> | Store X in register 0 |
| 03 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">1</kbd> | Store 1 in X |
| 04 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">LBL</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd> | Define label 00 |
| 05 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">RCL</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">×</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd> | Recall register 0 and multiply with X |
| 06 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">DSE</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd> | Decrement register 0 and if not zero ... |
| 07 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">GTO</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd><kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">0</kbd> | ... go back to label 00 |
| 08 | <kbd class="keyboard-key" style="border: 1px solid; border-color: #ddd #bbb #bbb #ddd; border-bottom-width: 2px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px; background-color: #f9f9f9; padding: 1px 3px; font-family: inherit; font-size: 0.85em; white-space: nowrap;">RTN</kbd> | End program - result displayed in X |
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