Scroll Lock
From Free net encyclopedia
Scroll Lock is a key (with an associated status light) on most modern desktop computer keyboards. The behaviour of the key depends on the particular software in use.
The Scroll Lock key is a remnant from the original IBM PC keyboard. In the original design, Scroll Lock was intended to modify the behaviour of the arrow keys. When the scroll lock mode was on, the arrow keys would scroll the contents of a text window. In this sense, Scroll Lock serves a similar purpose to Num Lock and Caps Lock: it enables a secondary function of a group of keys. Today, this particular use of Scroll Lock is rare. Only a few modern programs still honour this behaviour, such as Microsoft Excel (in the behaviour of arrows — when Scroll Lock is on, the selection does not move) and Lotus Notes. In modern GUI environments, scrolling is usually accomplished using other means such as scrollbars. This is a defunct feature in almost all modern programs and operating systems.
In Linux command line sessions, the Scroll Lock key is used to pause screen output. This behaviour emulates the Hold Screen key or similar flow control mechanisms on computer terminals. Because of this emulation, the term scroll lock is sometimes used to generically refer to a screen pausing behaviour. This usage could potentially cause confusion since screen pausing behaviour is not intrinsically a part of the Scroll Lock key. In DOS, the Pause key pauses the screen output.
Other uses
In the Opera web browser the scroll key plays an important role in voice recognition. KVM switches often use the Scroll Lock key with a number as a hot key to activate a softswitch for changing between channels. In Xfire scroll lock is used to bring the program out of the system tray. In the multilingual text editor iLeap, Scroll Lock key is used as a toggle switch to change between two languages.
In FreeBSD, and other BSD descendants, Scroll Lock still functions similarly to IBM's original design.
iBooks do not have a Scroll Lock key on their keyboards.