KEYBOARD Keyboard is an input device which is similar to typewriter and has manyadditional keys. Keyboard has 104 keys including functional keys, symbols,control keys, arrow keys, and it also have LED indicators. The following imageof an Qwerty keyboard shows all the keys. Now aday USB, bluetooth keyboards are used with the coputers. But eariler thecomputer were using PS/2, serial as keyboard interface.
In keyboards,alphabets, numbers and symbol are printed on the keys. The keys in keyboard arenot only used to display the aplhabets and numbers but also use to pas commandsto the computer. Typesof Keyboard There are two types of keyboards. 1. Wired Keyboards: – The wired keyboard is day by daybecoming the past but still it is the most preferable keyboard.
The wired keyboarduses AT, PS/2 connectors. The wired Keyboard need the Drivers to operate thatis already installed in the computers. Now days the most commonly use wiredkeyboards are USB keyboards. The major Drawback of the wired keyboard is we cannotuse it from distance.
2. Wireless Keyboards: – Thewireless keyboard is now a day’s becoming so popular. A wireless keyboard usesinfrared technology, Bluetooth technology and radio frequency technology. Thewireless keyboards are used with computes, laptops, tablets.
Radio Frequencykeyboards transmit data using signal where infrared technology uses light fordata transmission. We can use these keyboards from the distance. Means if weare using Bluetooth wireless keyboard than we can use it from distance upto therange of the Bluetooth keyboard. There are many other keyboards used fordifferent purpose such as laptop keyboard, gaming keyboards, laser keyboardsand Ergonomic keyboards,membrane keyboards, etc. Below each key there is a small hole and a smallcylinder bar of same size.
When the key is pressed, the bar is pushed down andtouches the contact layer below. Inside the bar there is a small rubber thatpushes back the key up. This is how the system is able to know which key ispressed. There are some light indicators with some keys such as num keys caps lockkeys.