Function keys

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Function keys are general-purpose numbered softkeys found on the majority of computer keyboards. The number of function keys varies between computer systems; IBM-compatible computers typically have 12, while Macintosh computers have more: 15 on the Matias Tactile Pro 3, and 19 on the aluminium Apple Keyboard.

Function keys are typically labelled in the sequence { F1, F2, F3 … } but some keyboards start counting at zero.

Programmable function keys on programmable keyboards are typically labelled from PF1 upwards. The behaviour of function keys is operating system or software defined, while programmable function keys have user-defined behaviour, for example macro execution.

Count

Ten function keys was the typical amount on older keyboards; the IBM Model M increased the count to 12, and Apple have since increased the number further, variously using zero, 15, 12, 16 and 19[1]. Conversely, the Commodore 64 only had four physical keys, labelled f 1/f 2 to f 7 /f 8, an approach found on several manufacturers' products.

Position

Function keys are typically placed on the top row of keys. However, the placement has varied over time.

Side

Function keys were frequently placed on the left-hand side of early keyboards, in two columns. Side layout has recently made a comeback with macro keys on gaming-orientated keyboards.

Top

The IBM Model M is noted for moving the function keys from the left to the top, although it was not the first computer to feature them in this position.

Arrangement

Numbering

Secondary functionality

On some keyboards, the conventional functionality—scancodes for F1–12—are secondary in nature to some other functionality. An additional key such as Fn must be held to trigger F1–12. In the case of a laptop, this may be reversible within the BIOS, such that (for example, with a Dell Inspiron 15) pressing the F5 key will again refresh a web page instead of increase the screen brightness.

Bindings

Microsoft Windows

Common bindings for Windows applications are:

F1 Help
F2 Rename the selected item
F3 Find
F5 Refresh
F6 Switch panel
F10 Focus the menu bar (the same as pressing Alt; shift-F10 opens a context menu the same as the menu key)

Macintosh

See also

References

  1. Tastatur / Keyboard 1968 - 2007 at Mauseum.net