Num key

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A Num key with an integrated LED

The Num Lock or Num Lock key is a key on a computer keyboard . It is located on the top left of the number pad . It was introduced especially for the IBM PC and therefore does not exist on every keyboard.

purpose

The Num Lock key is a caps lock key similar to the scroll key or the toggle lock . Their status is usually shown by a small LED light, and on some notebooks also on an LCD. When activated, the numeric keypad can be used to enter digits; if it is switched off, the cursor can be controlled with the number pad.

The double assignment of the keys u, i, p, k, l, ö, m is labeled here in light blue

On narrower keyboards (as is common with small laptops) there is often no space for a number pad. In this case, the Num Lock key switches some of the letter keys so that they can be used as a number block (for quick number entry). The alternatively active characters are usually marked in a different color on the buttons (see picture).

With the key combination Left Shift + Left Alt + Num Lock , the keyboard mouse can be switched on or off in Windows and in some other operating systems .

origin

The original keyboard on the IBM PC only had 83 keys. Therefore it did not have a separate cursor block, and instead the number block could be used either for entering numbers (Num-Lock on) or as a cursor block (Num-Lock off); here are from the buttons 4, 8, 6and 2, for example, the four direction keys, and from 1the end key, etc.

Later keyboards had a separate cursor block, but instead of saving the Num-Lock key, as it would have been logical, it was retained and the number block could now be made into a second cursor block.

criticism

The Num Lock key is often perceived as an anachronism - PC keyboards without the separate cursor pad that required them were the standard for only five years, while it has been over 20 years since then.

The "normal" state of a caps lock key is usually signaled by a switched off light, as is the case with the toggle lock or the scroll key ; with Num-Lock it has been the other way around since 1986, since there (at least on desktop computers) the switched-on state is the normal state. Some Windows computers start without Num-Lock, i.e. with the lamp switched off; on some, the status can be configured in the BIOS so that it can then be changed again when the operating system starts. Newer Windows versions remember the current state of the key when the system is shut down and restore it the next time the system is started.

An incorrect state quickly leads to confusion and incorrect entries. Especially on notebooks you have to pay attention to the status of the Num-Lock key, because the function has been taken over exactly: active Num-Lock provides numbers, inactive Num-Lock provides the letters. This is a problem with occasional full keyboard use on these mobile devices. Without an external keyboard, Num Lock must be OFF in order to be able to write the letters; with an external keyboard you want to use the numbers on the numeric keypad and therefore need Num Lock ON.