A function key is a key on a computer or terminal keyboard which can be programmed so as to cause an operating system command interpreter or application program to perform certain actions. A computer is a Machine that manipulates data according to a list of instructions. A computer terminal is an electronic or electromechanical hardware device that is used for entering data into and displaying data from a Computer or a Computing In Computing, a keyboard is an Input device partially modelled after the typewriter keyboard which uses an arrangement of buttons or keys On some keyboards/computers, function keys may have default actions, accessible on power-on.

A 102-key PC US English keyboard layout with the function keys in orange. The United States of America —commonly referred to as the English is a West Germanic language originating in England and is the First language for most people in the United Kingdom, the United States

Function keys on a terminal may either generate short fixed sequences of characters, often beginning with the escape character (ASCII 27), or the characters they generate may be configured by sending special character sequences to the terminal. American Standard Code for Information Interchange ( ASCII) On a standard computer keyboard, the function keys may generate a fixed, single byte code, outside the normal ASCII range, which is translated into some other configurable sequence by the keyboard device driver or interpreted directly by the application program. Function keys may have (abbreviations of) default actions printed on/besides them, or they may have the more common "F-number" designations.

Function key schemes on various computer keyboards

• Apple Macintosh: Early Mac OS supported system extensions known generally as FKEYS which could be installed in the System file and could be accessed with a Command-Shift-(number) keystroke combination (Command-Shift-3 was the screen capture function included with the system, and was installed as an FKEY); however, early Macintosh keyboards did not support numbered function keys in the normal sense. Macintosh, commonly nicknamed Mac is a Brand name which covers several lines of Personal computers designed developed and marketed by Apple Inc The Command key, known as the open-Apple key (as well as just "Apple" in documentation prior to the Apple Macintosh family of computers is a Modifier A screenshot, screen capture, or screen dump is an Image taken by the Computer to record the visible items displayed on the monitor Since the introduction of the Apple Extended Keyboard with the Macintosh II, however, keyboards with function keys have been available, though they did not become standard until the mid-1990s. The Apple Extended Keyboard is a keyboard that was sold on its own and prepackaged with Apple Professional Desktops during the early 1990s (starting with the Macintosh IIsi They have not traditionally been a major part of the Mac user interface, however, and are generally only used on cross-platform programs. Current Mac keyboards include specialized function keys for controlling sound volume. The most recent Mac keyboards include 19 function keys, but keys F1-F4 and F7-F12 by default control features such as volume, media control, and Exposé. Exposé is a feature of the Mac OS X Operating system. First previewed on 23 June 2003 at the Worldwide Developers Conference
• Apple Macintosh notebooks: Function keys were not standard on Apple notebook hardware until the introduction of the PowerBook 5300 and the PowerBook 190. Macintosh, commonly nicknamed Mac is a Brand name which covers several lines of Personal computers designed developed and marketed by Apple Inc A laptop computer, also known as a notebook computer, is a small Personal computer designed for mobile use. For the most part, Mac laptops have keys F1 through F12, with pre-defined actions for some, including controlling sound volume and screen brightness.
• Apricot PC/Xi: six unlabelled keys, each with a LED beside it which illuminates when the key can be used; above the keys is a liquid crystal display—the 'microscreen'—that is used by programs to display the action performed by the key. The Apricot PC was Apricot Computers ' first Personal computer made for Business use
• Atari 8-bit family (400/800/XL/XE): four dedicated keys (Reset, Option, Select, Start) at the right hand side or on the top of the keyboard; the XL models also had a Help key. The Atari 8-bit family is a series of 8-bit Home computers manufactured from 1979 to 1992 A Help key, found in the shape of a dedicated key explicitly labeled "Help" or as another key typically one of the Function keys on a Computer keyboard Atari 1200XL had four additional keys labeled F1 through F4 with pre-defined actions, mainly related to cursor movement.
• Atari ST: ten parallelogram-shaped keys in a horizontal row across the top of the keyboard, inset into the keyboard frame instead of popping up like normal keys. The Atari ST is a home / Personal computer that was commercially available from 1985 to the early 1990s In Geometry, a parallelogram is a Quadrilateral with two sets of Parallel sides
• BBC Micro: red/orange keys F0 to F9 in a horizontal row above the number keys on top of the computer/keyboard. The break, arrow, and copy keys could function as F10-F15.
• Coleco Adam: six dark brown keys in a horizontal row above the number keys, labeled with Roman numerals I-VI. The Coleco Adam was a Home computer, an attempt in the early 1980s by American toy manufacturer Coleco to follow on the success of its ColecoVision
• Commodore VIC-20 and C64: F1/F2 to F7/F8 in a vertical row of four keys ascending downwards on the computer/keyboard's right hand side, odd-numbered functions accessed unshifted, even-numbered shifted; orange, beige/brown, or grey key color, depending on VIC/64 model/revision. The VIC-20 ( Germany: VC-20; Japan: VIC-1001) is an 8-bit Home computer which was sold by Commodore Business Machines
• Commodore 128: essentially same as VIC-20/C64, but with (grey) function keys placed in a horizontal row above the numeric keypad right of the main QWERTY-keyboard; also had Help key. The Commodore 128 ( C128, CBM 128, C=128) home / Personal computer was the last 8-bit machine which was commercially A Help key, found in the shape of a dedicated key explicitly labeled "Help" or as another key typically one of the Function keys on a Computer keyboard
• Commodore Amiga: ten keys arranged in a row of two 5-key groups across the top of the keyboard (flush with the ordinary keyboard top row); function keys are 1½ times the width of ordinary keys. The Amiga is a family of Personal computers originally developed by Amiga Corporation. Like the Commodore 128, this also had a Help key. A Help key, found in the shape of a dedicated key explicitly labeled "Help" or as another key typically one of the Function keys on a Computer keyboard
• Graphing calculators, particularly those from Texas Instruments, Hewlett-Packard and Casio, usually include a row of function keys with various preassigned functions (on a standard hand-held calculator, these would be the top row of buttons under the screen). A graphing calculator (also known as a graphic calculator or graphical calculator) typically refers to a class of handheld Calculators that are capable of Texas Instruments ( better known in the electronics industry (and popularly as TI, is an American company based in Dallas, Texas, USA ( is a Japanese electronic devices manufacturing company founded in 1946 with its Headquarters in Tokyo. On low-end models such as the TI-83-series, these function mainly as an extension of the main keyboard, but on high-end calculators the functions change with the mode, sometimes acting as menu navigation keys as well. The TI-83 series of Graphing calculators is manufactured by Texas Instruments.
• HP 2640 series terminals: first known instance—late 1970s—of screen labeled function keys (where keys are placed in proximity or mapped to labels on CRT or LCD screen). The HP 2640A and other HP 264X models were block-mode "smart" and intelligent ASCII standard serial terminals produced Screen-labeled function keys are a special case of Function keys where keys are placed near a screen which provides labels for them
• HP 9830: f1–f8 on two rows of four in upper left with paper template label. The HP 9800 was a family of what were initially called programmable Calculators and later Desktop computers made by Hewlett-Packard which replaced their first Also on HP 2640 terminals. The HP 2640A and other HP 264X models were block-mode "smart" and intelligent ASCII standard serial terminals produced An early use of function keys (1972).
• IBM 3270: early models had 12 function keys in a 3×4 matrix at the right of the keyboard, later 24 in two rows on top of the keyboard. The IBM 3270 is a class of terminals made by IBM since 1972 (known as "display devices" normally used to communicate with IBM mainframes
• IBM PC AT and PS/2 keyboard: F1 to F12 usually in three 4-key groups across the top of the keyboard (the original IBM PC and PC XT keyboards had function keys F1 through F10, in two adjacent vertical rows on the left hand side; F1|F2, F3|F4, . The IBM PC keyboard and its derivative Computer keyboards are standardized . . , F9|F10, ascending downwards). Many modern PC keyboards also include specialized keys for multimedia and operating system functions.
• MCK-142 Pro: two sets of F1–F12 function keys, 1 above QWERTY and one to the left. Also, 24 additional user programmable PF keys located above QWERTY keys.

In MSX BASIC, the labels on the lowest row mark the text that would appear upon pressing each of the corresponding five function keys. MSX BASIC is a dialect of the BASIC programming language. It is an extended version of Microsoft Standard BASIC Version 4

• Sharp MZ-700: blue keys F1 to F5 in a horizontal row across the top left side of the keyboard, the keys are vertically half the size of ordinary keys and twice the width; there's also a dedicated 'slot' for changeable key legend overlays (paper/plastic) above the function key row.
• VT-100 terminals: four function keys (PF1, Alt; PF2, help; PF3, menu; PF4, escape to shell^[1]) above the numeric keypad. VT100 is a video terminal which was made by Digital Equipment Corporation (DEC A numeric keypad, or numpad for short is the small palm-sized seventeen key section of a Computer keyboard, usually on the very far right

Action of function keys on various programs, operating systems

In the Mac OS up to Mac OS 9, the function keys could be configured by the user, with the Function Keys control panel, to start a program or run an AppleScript. Mac OS is the trademarked name for a series of Graphical user interface -based Operating systems developed by Apple Inc Mac OS 9 is the final major release of Apple's "Classic" Mac OS. AppleScript is a Scripting language devised by Apple Inc, and built into Mac OS. Mac OS X assigns default functionality to F9, F10, and F11 (Exposé); F12 (Dashboard); and F14/F15 (decrease/increase contrast). Mac OS X (mæk oʊ ɛs tɛn is a line of computer Operating systems developed marketed and sold by Apple Inc, the latest of which is pre-loaded on all currently Exposé is a feature of the Mac OS X Operating system. First previewed on 23 June 2003 at the Worldwide Developers Conference Dashboard is an application for Apple 's Mac OS X operating systems used for hosting mini-applications known as widgets. On newer Apple laptops, all the function keys are assigned basic actions such as volume control, brightness control, NumLock (since the laptops lack a keypad), and ejection of disks. Software functions can be used by holding down the Fn key while pressing the appropriate function key, and this scheme can be reversed by changing the Mac OS X system preferences. Fn key can also refer to the Function keys on a Computer keyboard.

The lowest row of the GW-BASIC screen associated the PC function keys to BASIC commands. GW-BASIC was a dialect of BASIC developed by Microsoft from BASICA, originally for Compaq.

Under MS-DOS, individual programs could decide what each function key meant to them, and the command line had its own actions (e. MS-DOS (short for M icro' s' oft D isk O perating S ystem is an Operating system commercialized by Microsoft. g. , F3 copied to the current command prompt words from the previous command). Following the IBM Common User Access guidelines, the F1 key gradually became universally associated with Help in most early Windows programs. Common User Access ( CUA) is a standard for User interfaces to Operating systems and Computer programs It was developed by IBM and first To this day, Microsoft Office programs running in Windows list F1 as the key for Help in the Help menu. Microsoft Office is a set of interrelated desktop applications servers and services collectively referred to as an Office suite, for the Microsoft Windows and Internet Explorer in Windows does not list this keystroke in the help menu, but still responds with a help window. F5 is also commonly used as a refresh key in many web browsers and other applications, while F11 activates the full screen/kiosk mode on most browsers. A web browser is a software application which enables a user to display and interact with text images videos music games and other information typically located on a Kiosk software is the system and User interface software designed for a Kiosk or Internet kiosk. Under the Windows environment, the Alt-F4 key is commonly used to quit or close portions of an application.

Other function key assignments common to all Microsoft Office applications are: F7 to check spelling, Alt-F8 to call the macros dialog, Alt-F11 to call the Visual Basic Editor and Shift-Alt-F11 to call the Script Editor. In Microsoft Word, Shift-F1 reveals formatting. In Microsoft PowerPoint, F5 starts the slide show, and F6 moves to the next pane.

WordPerfect for DOS is one of the programs that made heavy use of function keys. WordPerfect is a proprietary Word processing application At the height of its popularity in the late 1980s and early 1990s it was the De facto

Function Keys are also heavily used in the BIOS interface. In Computing, the BIOS (ˈbaɪoʊs Generally during the power-on self-test, BIOS access can be gained by hitting either a function key or the delete key. Power-on self-test (POST is the common term for a computer router or printer's pre-boot sequence. In the BIOS keys can have different purposes depending on the BIOS. However, F10 seems to be a fairly wide standard for save and exit which saves all changes and restarts the system.

References

1. ^ Ignite-UX Administration Guide: for HP-UX 11. HP-UX (Hewlett Packard UniX is Hewlett-Packard 's proprietary implementation of the Unix Operating system, based on System V (initially 00 and 11i, Appendix D (Terminal Keyboard Shortcuts), Advanced Keyboard Navigation.

IBM/Windows keyboard (US layout) v • d • e
Esc		F1	F2	F3	F4		F5	F6	F7	F8		F9	F10	F11	F12		PrtSc	ScrLk	Pause
																	Ins	Home	PgUp		NumLk	/	*	-
																	Del	End	PgDn		7	8	9	+
																					4	5	6
																		↑			1	2	3	Ent
																	←	↓	→		0		.