Esc key

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For other uses, see ESC.
A computer keyboard. The Esc key is in the top-left corner.
IBM 83-key keyboard (1981), with Esc in the top-left corner of the alphanumeric section.

On computer keyboards, the Esc key (named Escape key in the international standard series ISO/IEC 9995) is a key used to generate the Escape character (which can be represented as ASCII code 27 in decimal, Unicode U+001B, or Ctrl+[, the traditional escape sequence).

It is generally placed at the top left corner of the keyboard, which placement dates at least to the original IBM PC keyboard, though the key itself dates to teletypewriters.

Symbol[edit]

ISO keyboard symbol for "Escape"

The keyboard symbol for the ESC key (which may be used when the usual Latin lettering "Esc" is not preferred for labelling the key) is standardized in ISO/IEC 9995-7 as symbol 29, and in ISO 7000 "Graphical symbols for use on equipment" as symbol ISO-7000-2029. This symbol is encoded in Unicode as U+238B broken circle with northwest arrow (⎋).

Origins[edit]

The Escape key's creation is credited to Bob Bemer, a computer programmer who worked for IBM. He created the Escape key in 1960 to allow programmers working with diverse machines to switch from one type of code to another.[1][2]

Uses[edit]

As most computer users no longer are concerned with the details of controlling their computer's peripherals, the task for which the escape sequences were originally designed, the escape key was appropriated by application programmers, most often to mean Stop. This use continues today in Microsoft Windows's use of escape as a shortcut in dialog boxes for No, Quit, Exit, Cancel, or Abort, as well as a common shortcut key for the Stop button in many web browsers.[3][4][5]

On machines running Microsoft Windows, prior to the implementation of the Windows key on keyboards, the typical practice for invoking the "start" button was to hold down the Control key and press escape. This key combination still works as of Windows 8.[6]

Microsoft Windows makes use of "Esc" for many key shortcuts.[7] Many of these shortcuts have been present since Windows 3.0, through Windows XP, Windows Vista, Windows 7, and Windows 8.

In OS X, "Esc" usually closes or cancels a dialog box or sheet. The Command+ Option+Esc combination opens the Force Quit dialog box, allowing users to end non-responsive programs. Another use for the Esc key, in combination with the Command key, is switching to Front Row, if installed.

In most computer games, the escape key is used as a pause button and/or as a way to bring up the in-game menu, usually containing ways to exit the program.

ADM-3A keyboard layout used in vi development, with escape in what is now the tab position

In the vi family of text editors, escape is used to switch modes. This usage is due to escape being conveniently placed in what is now the tab position on the ADM-3A terminal keyboard used to develop vi, though it is now inconveniently placed. This is similar to how the extensive modifier keys in emacs were easily used on the original keyboard (the space-cadet keyboard), being placed together, but these keys have now been spread around the keyboard, becoming more difficult to use.

References[edit]