UNDERSTANDING HARDWARE

Any working system in the universe like human digestive system, writing on a piece of paper, using pens or pencils, making and drinking a cup of coffee etc., can be divided into THREE important MODULES:

Likewise a computer also consists of an input, an output and a processor. In a computer the processor is called a CENTRAL PROCESSING UNIT (CPU).

In general, the data INPUT to the computer is given through a keyboard, which is similar to that of a typewriter keyboard with enhanced keys. A separate numeric key pad, special function keys, enter, control, alter, escape, print screen, scroll lock, pause keys are available in a computer key board. (It is also called as "QUERTY" keyboard, since these five letters are the first five keys in the Second Row - first row of letters - of a typewriter key board). Other INPUT devices are scanner, mouse, CD-ROM, floppy drive, web cam, etc.

Monitor is used as an OUTPUT device TO VIEW the data, which is keyed in through a keyboard. In general it is called as a VIDEO DISPLAY UNIT (VDU). Other OUTPUT devices are printers, plotters, floppies, hard disks, liquid crystal display (LCD) for projection etc.

BINARY SYSTEM

Unlike our numerical system, which we call as DECIMAL system, computers have been built to deal with (store and understand) BINARY system.Consists of numbers 0 and 1 only. These numbers should be represented as (1010)2 - value to a base of 2.

DECIMAL SYSTEM

Consists of numbers from 0 to 9. Any number in this system should be denoted by (25)10 - numerical value to a base of 10. In general this is not written.