People don’t think of their keyboards miniature computers attached to their primary computer, but that’s, in effect, what they are.
The computer keyboard you use for work contains circuitry which converts your inputs into signals your processor can understand. It has to have this feature; otherwise, all of the processing would have to be done on the chip, and that would make it hard for manufacturers to develop novel styles of keyboards.
Let’s Talk About Buttons
Your computer uses push button switches. Once you’ve finished pressing the switch, the keyboard button springs back up into its original position, breaking the circuit.
Some gaming devices use an illuminated momentary push button switch.
The concept here is much the same, the difference being that when you press a key on your keyboard, it lights up. Many RBG-backlit keyboards have this rather nice feature.
The Character Map
A “character map” might sound like a complicated concept, but it’s actually quite easy to understand. Its what your keyboard uses to converts the buttons you press into generic signals that it can then send to the central processor to interpret. Creating these generic signals is important. Keyboards need to interact with systems in a standard way, even if they’re different from each other in layout.
Alternative layouts are not a problem with the character map. It’s what decodes the inputs for the processor, telling it what each mean, even if you have a non-standard keyboard. So, for instance, you might have an unusual keyboard that splits in two in the middle (to make it easier for typing). The character map tells the process which is the shift key and with is the key for the letter “Z” so that when you press SHIFT+Z, you get a capital Z, not a lower case.
Overriding The Character Map
Processors aren’t stupid though. While a character map makes it easy for the processor to interpret the inputs from a keyboard automatically, it often doesn’t make sense to stick with it no matter what.
European and American keyboards, for instance, differ in subtle ways. The key to generate speech marks is often different on a keyboard from Europe compared to one from America. Different operating systems, like Linux, can also layer on their own character maps, overriding that of the keyboard, adding extra complexity to the process.
Keyboard Manufacturers Use A Variety Of Button Types
The switches on a keyboard are different from your lightswitches in that they’re only “on” when you press them (they don’t stay on). Manufacturers achieve this through a variety of methods.
Membrane keyboards, for instance, use a membrane that stretches from one side of the keyboard to the other. The membrane contains tiny wires under the buttons which completes a circuit when you push down on them. Rubber dome switches in laptops don’t use a sping and instead rely on the physical memory of the rubber from which they’re made.
