Editing Keyboard technology (section)

== Other parts <span class="anchor" id="Other parts of the personal computer keyboard"></span> ==
A modern PC keyboard typically includes a control processor and indicator lights to provide feedback to the user about what state the keyboard is in. Depending on the sophistication of the controller's programming, the keyboard may also offer other special features. The processor is usually a single chip [[Intel 8048|8048]] [[microcontroller]] variant. The keyboard switch matrix is wired to its inputs and it processes the incoming keystrokes and sends the results down a serial cable (the keyboard cord) to a receiver in the main computer box. It also controls the illumination of the "[[caps lock]]", "[[num lock]]" and "[[scroll lock]]" lights.

A common test for whether the computer has crashed is pressing the "caps lock" key. The keyboard sends the key code to the [[Device driver|keyboard driver]] running in the main computer; if the main computer is operating, it commands the light to turn on. All the other indicator lights work in a similar way. The keyboard driver also tracks the [[shift key|shift]], [[alt key|alt]] and [[control key|control]] state of the keyboard.{{cn|date=March 2025}}