Having discussed the the most popular output devices, i believe it would be a great time discussing the most prevalent and important input devices the ubiquitous keyboard and mouse. When desktop computers were first developed in the 1980s they used command like interfaces. Where you would see a blinking ”_” or underscore after you booted a computer and the only interface we had at the time were keyboards. Early computer keyboard used buckling spring style keycaps wherein a small spring lies under the key and when depress far enough the keyboard would register that keystroke. IBM’s famous model M used this buckling spring technology.
Soon after in the late 80’s membrane keyboards became more and more popular. They basically function by having a small dome of rubber with a conductor inside the dome, and when the user would press down the dome would deform and make contact with a circuit traces underneath. That contact would cause the traces to short and the keyboard would register a keypress. Scissor-switch keys often work with this membrane style domes but the keys are attached with x shaped supports underneath each key giving the keys a more restrained travel distance making keyboards thinner.
Now many gamers use Mechanical switch style keyboards for accuracy and consistent key travel. Each switch contains all the mechanisms to register a keypress. they are customizable, durable and modular.
In 1984 apple released the Macintosh which ran the first full commercial GUI or graphical user interface. This Computer used a mouse to help users interface with the computer allowing user to “click” command on screen instead of having to type out command with proper syntax to operate a computer. This moved the mouse to the forefront of computer interfaces, and allowed a much wider audience to be able to use comperters,a dn made most tasks as single as click a mouse. A mouse is a simple device used to register movement in two dimensions in space and transmits those signals to a computer, and also register a button “click” or being depressed.
The computer mouse initially operate with a small rubber ball situated inside of it and 2 potentiometers with rollers on the top and side of it used to register the x and y movement of the device. And often a button on top the mouse to register click from the user. The ball needed a textured surface to “stick” to the surface and use friction to roll the rollers. This ball meant the mouse had to be cleaned often because the ball would pick up dust and detrus and loose friction with the rollers. Now most mice use optical lasers or specialized LEDs and light receptors to register movement this reduce moving parts in the mouse and reduced and often eliminate the need to clean the mouse.
In the beginning these input devices used a serial style port eventually they got their own ports known as PS/2 ports. But now many computers uses USB connectors or Bluetooth wireless technology to connect to these inputs.