| HP-45 | |
| Type: | Scientific |
| Entry: | RPN |
| Introduced: | 1973 |
| Discontinued: | 1976 |
| Display Type: | Red LED seven-segment display |
| Display Size: | 15 digits (decimal point uses one digit), (±10±99) |
| Prog Lang: | RPN key stroke |
| Memory Data: | Four-register operational stack with nine addressable memory registers + LASTx register |
| Supply: | Internal rechargeable battery or 115/230 V AC, 5 W |
| Weight: | Calculator: 9oz, recharger: 5oz |
| Dimensions: | Length: 5.8inches, width: 3.2inches, height: 0.7inches–1.3inchesin (–in) |
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] . Especially noteworthy was its pioneering addition of a shift key that gave other keys alternate functions.
The calculator was code-named Wizard,[3] 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.[4] [5] An accurate version of the stopwatch mode was officially featured in the 1975 successor of the HP-45, the HP-55.
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%,, vector arithmetic, register arithmetic. Statistical accumulation with mean and standard deviation calculations. Fixed point and scientific display modes, 0 – 9 decimal places round-off. | |
Several individuals and companies make software emulators of the HP 45 series calculators.
The complete design of the calculator and its firmware is patented under .