Characters are represented using character sets like ASCII and Unicode. ASCII uses 7 bits for 128 characters while Extended ASCII uses 8 bits for 256 characters. Unicode was developed to represent more languages and uses 16 bits, allowing it to store up to 65,536 characters to support international communication needs beyond what ASCII provided. The document discusses the evolution of character set standards from ASCII to Extended ASCII to Unicode.

2. Representation of Text A character is a symbol or letter on the keyboard. A list of all the characters a computer and peripheral device can process and control is called the character set . Each character is represented by a unique binary code.

3. ASCII The internationally agreed code used to represent American English is the American Standard Code for Information Interchange or ASCII . ASCII uses 7 bits to represent each character from 0000000 to 1111111 which can be used to store 128 characters. The codes 0 - 31 represent control characters which are special non-printing characters e.g TAB and Return.

4. ASCII Extended ASCII , which was created when IBM designed its PCs, uses 8 bits to represent each character. from 0000000 to 1111111 which can be used to store 256 characters.

5. Unicode The fact that ASCII can only represent at most 256 characters creates problems for international communication. The 256 characters are based on European alphabets and do not contain Arabic or Japanese characters. The solution was development of the Unicode character set which uses 16 bits to represent each character. from 0000000 to 1111111 which can be used to store 65,536 characters.

6. Credits Higher Computing – Data Representation – Representation of Text Produced by P. Greene and adapted by R. G. Simpson for the City of Edinburgh Council 2004 Adapted by M. Cunningham 2010 All images licenced under Creative Commons 3.0 Rainbow of Books by Dawn Endico Close up of a black keyboard by John Ward