HP-45
Scientific pocket calculator
From Wikipedia, the free encyclopedia
The HP-45 is the second scientific pocket calculator introduced by Hewlett-Packard, adding to the features of the HP-35. It was introduced in 1973[1] with an MSRP of US$395[2] (equivalent to $2,865 in 2025).[3] Especially noteworthy was its pioneering addition of a shift key that gave other keys alternate functions.
HP-45 Advanced Scientific Electronic Pocket Calculator | |
| Type | Scientific |
|---|---|
| Introduced | 1973 |
| Discontinued | 1976 |
| Calculator | |
| Entry mode | RPN |
| Display type | Red LED seven-segment display |
| Display size | 15 digits (decimal point uses one digit), (±10±99) |
| Programming | |
| Programming language(s) | RPN key stroke |
| Memory register | Four-register operational stack with nine addressable memory registers + LASTx register |
| Other | |
| Power supply | Internal rechargeable battery or 115/230 V AC, 5 W |
| Weight | Calculator: 9 oz (260 g), recharger: 5 oz (140 g) |
| Dimensions | Length: 5.8 inches (150 mm), width: 3.2 inches (81 mm), height: 0.7–1.3 inches (18–33 mm) |
The calculator was code-named Wizard,[4] which is the first known use of a code name for a calculator.
It also contained an Easter egg that allowed users to access a not-especially accurate stopwatch mode.[5][6] An accurate version of the stopwatch mode was officially featured in the 1975 successor of the HP-45, the HP-55.
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The display of the HP-45 hidden timer showing 00 hours 00 minutes 07 seconds and 58/100 second.
| HP-45 functions | |
|---|---|
| Arithmetic | +, −, ×, ÷ |
| Trigonometry | sin, arc sin; cos, arc cos; tan, arc tan (decimal degrees, radians or grads). |
| Logarithms | log10x, 10x; logex, ex |
| Conversions | Decimal degrees, radians or grads ↔ degrees–min.–sec. Rectangular coordinates ↔ polar coordinates. Conversion units: cm/in, kg/lb, ltr/gal |
| Other | 1/x, √x, x2, yx, n!, %, Δ%, π, vector arithmetic, register arithmetic. Statistical accumulation with mean and standard deviation calculations. Fixed point and scientific display modes, 0 – 9 decimal places round-off. |
Emulators
Several individuals and companies make software emulators of the HP 45 series calculators.
- Nonpareil, high-fidelity simulator for calculators
- Emulates, among other, the HP-45. Licensed under the GNU General Public License (GPL). Available for Microsoft Windows.
- HP-45 Emulator
- HP-45 Emulator written in Java. Licensed under the GPL 3. Available for Android[7] and Symbian.[8]
- HP-45 Windows Phone 7 App
- An Emulator for Windows Phone 7.
- HP-45 Emulator in JavaScript
- The HP-45 Program ROM was translated to JavaScript to have an exact simulation of the original calculator for use in web browsers.
- HP-45 Emulator in Python
- Simulates the HP-45 and displays and explains its inner workings. For Linux, MacOS, Windows, CP/M, and more, with minimal mode for low-power machines.
Patents
The complete design of the calculator and its firmware is patented under US 4001569A.