Computer programmers historically used "Press any key to continue" (or a similar text) as a prompt to the user when it was necessary to pause processing. The system would resume after the user pressed any keyboard button.
Early computers were typically operated using mechanical teleprinters, which provided a continuous printed record of their output. However, during the 1970s, these became obsolete and were replaced with visual display units, and text was lost once it scrolled off the top of the screen. To compensate, programs typically paused operation after displaying one screen of data, so that the user could observe the results and then press a key to move to the next screen.
These prompts were commonplace on text-based operating systems prior to the development of graphical user interfaces, which typically included scrollbars to enable the user to view more than one screen/window of data. They are therefore no longer required as a means of paginating output, but the graphical equivalent (such as a modal dialog box containing the text "Click OK to continue") is still used for hardware interactions.
The prompt is not strictly accurate in that, for the vast majority of computer systems, modifier keys or lock keys would not cause processing to resume, as they do not produce an actual character that the program could detect.
A 1982 Apple Computer manual for developers warned:
Do not tell the user to "press any key." ... On the Apple II series computers, you cannot read every key by itself:
CONTROL. We have also found in testing that new users, in particular, panic when asked to press any key. Over 80% of them will turn around and say, "but what key should I press?" In questioning them about this response, we discovered that they are quite convinced that even though the prompt implied that all keys were OK to press, some could be dangerous. Of course, they were quite right.
There are reports from as early as 1988 that some users have searched for such a key labelled "any", and called technical support when they have been unable to find it. The computer company Compaq even edited their FAQ to explain that the "any" key does not exist, and at one point considered replacing the command "Press any key" with "Press return key".
ANY keys" with adhesive backings are available as novelty gifts.
In ex-USSR computer slang
The phrase "press any key to continue" (and its relatives) caused a slangy (but widely known) word эникейщик (enikeyshchik) to appear in Russian language, which has meaning of an administrator or a support worker (usually of a low rank), whose role is to help (often novice) users struggling with (often trivial) PC-related difficulties (like the aforementioned "press any key to continue" message). Often it's a derogatory term, contrasting an enikeyshchik to a "real" system administrator or higher-level support officer who solve more complex tasks – but not always. Even a slang verb "эникеить" (enikeyit') exists with meaning to perform a (usually low-level) computer administration and support.
Additionally, in Russian and ex-USSR computer jargon, the term "any key" is sometimes associated with the reset button of a PC. Explanations of such association vary: from considering it as being based on real pranks when some more advanced (in computers and in English) office workers had put stickers "Any key" to the reset buttons of their office computers, causing their less experienced colleagues to misinterpret the message – to considering it just as being a sarcasm about software-related difficulties solving skills of novice users (seeing a message you didn't expect? ahh, panic! don't even try to read it and understand!! just press reset!!!), or a Murphy's law-similar pessimism about actual resolvability of some types of work-flow problems caused by bugs in software.
- Meyers, Joe; Tognazzini, Bruce (1982). Apple IIe Design Guidelines (PDF). Apple Computer. p. 34.
- "Fantastic Voyages II / The Whirlwind Tour inside the Entertainment Industry Continues". Computer Gaming World. November 1988. p. 42.
- Jared Sandberg (2007-02-20). "'It Says Press Any Key; Where's the Any Key?'; India's Call-Center Workers Get Pounded, Pampered". Wall Street Journal. p. b1.
- Compaq FAQ: Where do I find the "Any" key on my keyboard
- Nick Farrell (2006-12-18). "Compaq tells punters where the 'any' key is". The Inquirer. Retrieved 2008-01-23.
- Ashlee Vance (2003-09-25). "Compaq FAQ explains the 'Any Key'". The Register. Retrieved 2008-01-23.
- Bill Kirby (1999-10-29). "Technology often tests creativity". Augusta Chronicle. Retrieved 2009-02-16.
- Jeffrey Kent (2004). C++ Demystified. McGraw Hill. p. 245. ISBN 0-07-225370-3.
- "Gag items offer relief in world of bits, bytes". The Deseret News. 1999-03-30. Retrieved from Newsbank on 2009-02-15.
- Search for the word "эникейщик" through dictionaries (in Russian)
- Social variants of language II: materials of international scientific conference on April 24-25, 2003 (in Russian)
- Tatyana Gennadyevna Nikitina "Slang of young people (explanatory dictionary)" (in Russian)
- Gazeta.Ru: Dmitriy Turetskiy "Let's talk about slang" (in Russian)