ASCII / ISCII / UNICODE

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    Internal storage of encoding characters
  A computer is capable of handling numeric data but in addition to numerical data, a          computer must be able to handle non-numerical information. In other words, a              computer should recognize codes that represent letters of the alphabet,                            punctuation and other special characters as well as numbers. These codes are            called alphanumeric codes.



1.     ASCII (American Standards Code for Information Interchange)
ASCII code is most widely used alphanumeric code used in computers. It is used extensively in small computers, peripherals, instruments and communication devices. ASCII-7 can represent 27=128 characters. ASCII-8 can represent 28=256 characters. It is an extended form ASCII-7. ASCII code is used for the transfer of alphanumeric information between a computer and I/O devices. A computer uses this code to internally store the information that an operator types in the computer’s keyboard.







2.    Extended ASCII Codes





3.     ISCII: (Indian Standard Code for Information Interchange)
A lot of efforts have gone into facilitating the use of Indian languages on computers. In 1991, the Bureau of Indian Standards adopted the ISCII. It is an 8-bit code which allows English and Indian Scripts alphabets to be used simultaneously. Characters coded in ISCII need 8 bits for each character. A special keyboard layout for entering ISCII called INSCRIPT was also specified and adopted.

4.    Unicode
Unicode is a new universal coding standard adopted by all new platforms. It is promoted by Unicode Consortium which is a non-profit organization. Unicode provides a unique number for every character irrespective of the platform, program and the language. It is a character coding system designed to support the worldwide interchange, processing, and display of the written texts of the diverse languages. The latest version contains a repertoire of 136,755 characters covering 139 modern and historic scripts.


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