View source for HP-45

{{Use dmy dates|date=April 2019|cs1-dates=y}}
{{Infobox Calculator
| name         = HP-45
| image        = HP-45.jpg
| caption      = HP-45<br />Advanced Scientific Electronic Pocket Calculator 
| type         = [[Scientific calculator|Scientific]]
| entry        = [[RPN input mode|RPN]]
| introduced   = 1973
| discontinued = 1976
| processor    = 
| display_type = Red [[Light-emitting diode|LED]] [[seven-segment display]]
| display_size = 15 digits (decimal point uses one digit), (±10<sup>±99</sup>)
| prog_lang    = [[Reverse Polish Notation|RPN]] key stroke
| memory_data  = Four-register operational stack with nine addressable memory registers + LASTx register 
| memory_step  = 
| supply       = Internal rechargeable battery or 115/230&nbsp;V&nbsp;AC, 5&nbsp;W 
| weight       = Calculator: {{convert|9|oz|g|abbr=on}},<br />recharger: {{convert|5|oz|g|abbr=on}}
| dimensions   = Length: {{convert|5.8|in|mm}},<br />width: {{convert|3.2|in|mm}},<br />height: {{convert|0.7|–|1.3|in|mm}} 
}}

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<ref>{{cite web |url=http://www.hp.com/hpinfo/abouthp/histnfacts/museum/personalsystems/0040/index.html |title=HP Virtual Museum: Hewlett-Packard-45 advanced scientific pocket calculator, 1973 |access-date=2017-10-15}}</ref> with an [[Suggested retail price|MSRP]] of [[US$]]395<ref>{{Cite web |url={{Google books|1T4ORu6EICkC|page=124|plainurl=yes}} |title=Those incredible new scientific pocket calculators |last=Free |first=John R. |page=124 |magazine=Popular Science |date=April 1974 |access-date=2017-10-15}}</ref> ({{Inflation|US|395|1973|fmt=eq}}).{{Inflation-fn|US}} Especially noteworthy was its pioneering addition of a [[shift key]] that gave other keys alternate functions.

The calculator was code-named ''Wizard'',<ref>{{cite web | author-first=Włodzimierz "Włodek" Anthony Christopher |author-last=Mier-Jędrzejowicz | title=THE HP-45 | website=HP CALCULATOR HISTORY | url=https://www.xnumber.com/xnumber/WMJ_hp45.htm}}</ref> which is the first known use of a code name for a calculator.<br />
It also contained an [[Easter egg (media)|Easter egg]] that allowed users to access a not-especially accurate [[stopwatch]] mode.<ref>{{cite web | last=Miller | first=Paul E. | title=HP-45 Calculator As A Stopwatch | website=Decode Systems | date=2016-08-31 | url=http://www.decodesystems.com/hp45-stopwatch.html}}</ref><ref>{{cite AV media|title=HP 45 Scientific Calculator Hidden Timer |url=https://www.youtube.com/watch?v=4TFV-zOzbd4 |language=en |access-date=2022-08-05 |via=youtube.com}}</ref> An accurate version of the stopwatch mode was officially featured in the 1975 successor of the HP-45, the [[HP-55]].

[[File:HP-45 (101587990).jpg]]<br />
The display of the HP-45 hidden timer showing 00 hours 00 minutes 07 seconds and 58/100 second.
{| class="wikitable" style="text-align:left"
! colspan=2 | HP-45 functions
|-
| Arithmetic || +, −, ×, ÷
|-
| Trigonometry || sin, arc sin; cos, arc cos; tan, arc tan (decimal degrees, radians or grads).
|-
| Logarithms || log<sub>10</sub>x, 10<sup>x</sup>; log<sub>e</sub>x, e<sup>x</sup>
|-
| Conversions || Decimal degrees, radians or grads ↔ degrees–min.–sec.<br/>Rectangular coordinates ↔ polar coordinates.<br /> Conversion units: cm/in, kg/lb, ltr/gal
|-
| Other || 1/x, √x, x<sup>2</sup>, y<sup>x</sup>, n!, %, Δ%, {{pi}}, vector arithmetic, register arithmetic.<br />Statistical accumulation with mean and standard deviation calculations.<br />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.

; [http://nonpareil.brouhaha.com/ Nonpareil, high-fidelity simulator for calculators]: Emulates, among other, the HP-45. Licensed under the [[GNU General Public License]] (GPL). Available for [[Microsoft Windows]].
; [https://web.archive.org/web/20120405051955/http://my.opera.com/HP-45/about HP-45 Emulator]: HP-45 Emulator written in [[Java (programming language)|Java]]. Licensed under the [[GPL 3]]. Available for [[Android (operating system)|Android]]<ref>{{cite web | last=Krischik | first=Martin | title=HP-45 scientific calculator | website=Apps on Google Play | date=2023-09-09 | url=https://play.google.com/store/apps/details?id=net.sourceforge.uiq3.hp45}}</ref> and [[Symbian]].<ref>{{cite web | title=HP-45 scientific calculator | website=smartsam.de | date=2009-05-10 | url=http://smartsam.de/48796/HP_45_scientific_calculator.html | archive-url=https://web.archive.org/web/20120422172822/http://smartsam.de/48796/HP_45_scientific_calculator.html | archive-date=2012-04-22 | url-status=dead |df=dmy-all }}</ref>
; [https://archive.today/20130209074140/http://www.windowsphone.com/de-AT/apps/03067e72-5b02-e011-9264-00237de2db9e HP-45 Windows Phone 7 App] : An Emulator for [[Windows Phone 7]].
; [https://norbertkehrer.github.io/hp45_js/hp45.html 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.
;[https://sarahkmarr.com/retrohp1973.html 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 {{patent|US|4001569A}}.

==References==
<references/>

==Further reading==
*{{patent|US|3892958A|Inverse/complementary function prefix key}} 

==External links==
* http://www.hpmuseum.org/hp45.htm
* http://www.digibarn.com/collections/calculators/hp45/index.html
* http://www.xnumber.com/xnumber/WMJ_hp45.htm

{{HP calculators}}

[[Category:HP calculators|45]]