(From the
IBM 3270 terminal's Programmed Function
Keys (PF keys)) One of a set of special keys on a computer or
terminal keyboard which can be programmed so as to cause an
application program to perform certain actions.
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.
On a
microcomputer 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.