Scroll lock

From Deskthority wiki
Jump to: navigation, search

This article is a stub. You can help Deskthority by expanding it.

Scroll Lock
Symbol
⤓ ⇳
X11 Scroll_Lock
USB Keyboard Scroll Lock (0x47)

Scroll lock is a rarely used lock key found on IBM PC-compatible keyboards.

In Microsoft Windows, there is no defined behaviour and the key is vestigial. Some programs such as Microsoft Excel have custom behaviour associated with this key.

The key halts output in the Linux console. It is supported in X but usually off by default.

Alternative

To paginate command line output, the output could be piped into a paginator command. The most common are known as more and less, the latter having more features.

Examples:

DOS command prompt
dir C:\Windows | more
POSIX shell
ls /usr | more
Windows PowerShell
dir C:\Windows | out-host -paging
In PowerShell, piping to more will cause the command on the left-hand-side to complete before continuing.
Third-party less commands exist that should work as on other systems.

Non-PC keyboards

DEC terminals

Terminals from Digital Equipment tend to have a key which halted output. The DEC VT100 has a NO SCROLL key in the bottom-left corner. The F1 key in the top-left key corner is mapped to Hold Screen on the VT-220 (DEC LK201) and to Hold Session on the VT-3x0 (DEC LK401). Some keyboards also have an indicator LED for the mode.

Acorn MOS

Acorn MOS does not support a scroll lock key. Instead, paged mode is enabled via control+N; after each page of output, both the caps lock and shift lock lights illuminate, and the system is halted (OSWRCH does not return) until shift is pressed. Control+O releases paged mode. There is no tactile or visual indication that paged mode is engaged. One might imagine that scroll lock would provide a similar behaviour under Windows, but it does not.