Function key

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 or pictographic representations of default actions printed on/besides them, or they may have the more common "F-number" designations.

The Singer/Friden 2201 Flexowriter Programmatic, introduced in 1965, had a cluster of 13 function keys, labeled F1 to F13 to the right of the main keyboard.

Although the Flexowriter could be used as a computer terminal, this electromechanical typewriter was primarily intended as a stand-alone word processing system.

The interpretation of the function keys was determined by the programming of a plugboard inside the back of the machine.

It can be noted that: Under MS-DOS, individual programs could decide what each function key meant to them, and the command line had its own actions.

Following the IBM Common User Access guidelines, the F1 key gradually became universally associated with Help in most early Windows programs.

F3 is commonly used to activate a search function in applications, often cycling through results on successive presses of the key.

Some applications such as Visual Studio support Control+F3 as a means of searching for the currently highlighted text elsewhere in a document.

A 104-key US English keyboard layout with the function keys in orange
Flexowriter keyboard (1968) with 13 function keys on the right
HP 9830A (1972) with 5×2 grid of 10 function keys at top left
Keyboard with 24 function keys
Tilde Exclamation mark At sign Number sign Dollar sign Percent sign Caret Ampersand Asterisk Parenthesis Parenthesis Underscore Plus sign Backspace Backtick 1 (number) 2 (number) 3 (number) 4 (number) 5 (number) 6 (number) 7 (number) 8 (number) 9 (number) 0 Hyphen-minus Equals sign Backspace Tab key Q W E R T Y U I O P Curly bracket Curly bracket Vertical bar Tab key Q W E R T Y U I O P Square bracket Square bracket Backslash Caps lock A S D F G H J K L Colon (punctuation) Quotation mark Enter key Caps lock A S D F G H J K L Semicolon Apostrophe Enter key Shift key Z X C V B N M Bracket Bracket Question mark Shift key Shift key Z X C V B N M Comma (punctuation) Full stop Slash (punctuation) Shift key Control key Windows key Alt key Space bar Alt key thumb Menu key Control key