WHICH FUNCTIONS OUTPUT DEVICES

OUTPUT DEVICES

Peripheral devices used to get information or result from a computer are called output devices. A number of output devices are available for use in computer systems and vaious cominations of them are found in common use. These include display units, printers. floppy drivers, hard disks and other display devices.

VIDEO MONITORS

The video display unit or video monitor is the most popular microcomputer output divice, primarily because it is fast, quiet and cheaper than a printing device. A video monitor consists of a cathode ray tube (CRT) which is a TV like secreen. The monitor is made specifically to display information and is very similar to a home TV except that it does not include the electronic circuits for receiving TV signals. A computer can communicate with the user through a video monitor by presenting the result/information in visual form. There are two types of monitors black and white or monochrome monitors and coloured monitors. Mononchrome monitors come in two varieties depending upon the shade of display, green and amber. There are basically two kinds of colour monitors composite and RGB. A composite monitor works the same way as colour TV set. An RGB monitor has three electron guns, a green gun and a blue gun. The image is sharper and more refined on an RGB than a composite monitor. Visual display devices fall mainly in two categories. Alphanumeric display units, which can display only text, others called graphic display devices. Visual display units also come in low resolutions medium resolution or high resolution graphic mode and can display graphics such as maps, charts, graphs, engineering drawings, animation figures and other types of pictorial information as well as alphabets and numerals.

PRINTERS

The printers are one of most useful output devices for use with a computer. Printers are used extremely mechanical peripherals to produce permanent output from the computer. These are classified into two main categories depending upon the type of print mechanism.

• Impact Printers
• Non Impact Printers

INPACT PRINTERS

Impact printers work like typewriters. These are further classififed into three types based on their spped of printing and number of characters perline. There are

• Dost Matrix Printers
• Daisy Wheel Printers
• Line Printers

continue...VIDEO MONITOR, PRINTERS