Data Representation

             Computers use the two-state system to represent data. Such a two state system is referred to as a binary system. In computers these two states are denoted by the digits 0 and 1 and any such value is called a binary digit or bit. In side the computer these two states are typically implemented by using two different voltages.

             The smallest unit of data that can be stored in a computer is a bit. A bit will have the value '0' or '1' . A large collection of such '0's or '1's is what makes up data in a computer.

Smallest Unit           = 1 bit

8 bits                     = 1 byte (B)

1024 bytes             = 1 kilobyte (KB)

1024 kilobytes        = 1 megabyte (MB)

1024 megabyte       = 1 gigabyte (GB)

1024 gigabyte         = 1 terabyte (TB)
(In computer jargon, One Kilo = 1024)

              The capacity of a particular storage device and the space taken up by a file are always measured using these units.

              Letters, numbers and special characters are represented within a computer by means of a binary coded scheme. Three popular binary coding schemes use eight bits to represent characters whereas Unicode uses 16 bits.

Character	ASCII-8	EBCDIC	Character	ASCII-8	EBCDIC
A B C D E F G H I J K L M	0100 0001 0100 0010 0100 0011 0100 0100 0100 0101 0100 0110 0100 0111 0100 1000 0100 1001 0100 1010 0100 1011 0100 1100 0100 1101	1100 0001 1100 0010 1100 0011 1100 0100 1100 0101 1100 0110 1100 0111 1100 1000 1100 1001 1101 0001 1101 0010 1101 0011 1101 0100	N O P Q R S T U V W X Y Z	0100 1110 0100 1111 0101 0000 0101 0001 0101 0010 0101 0011 0101 0100 0101 0101 0101 0110 0101 0111 0101 1000 0101 1001 0101 1010	1101 0101 1101 0110 1101 0111 1101 1000 1101 1001 1110 0010 1110 0011 1110 0100 1110 0101 1110 0110 1110 0111 1110 1000 1110 1001
0 1 2 3 4 !	0011 0000 0011 0001 0011 0010 0011 0011 0011 0100 0010 0001	1111 0000 1111 0001 1111 0010 1111 0011 1111 0100 0101 1010	5 6 7 8 9 ;	0011 0101 0011 0110 0011 0111 0011 1000 0011 1001 0011 1011	1111 0101 1111 0110 1111 0111 1111 1000 1111 1001 0101 1110

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