1 Non-Numeric Data Representation V1.0 (22/10/2005)

2 Non-Numeric Data Representation Non-Numeric data use specific form of characters to represent To save the text into bit sequence and decipher the bit sequence into text, there must be a standard character set-bit mapping table Different Presentation  ASCII  Big-5  GB  Unicode

3 ASCII Full term is American Standard Code for Information Interchange Short term is ASCII Use number 0 to 127 represent English character set Since commonly use on computer systems, its excellent for exchange information Standard ASCII character set only use 7 bits to represent one character In order to enhance character set, ASCII character set user 8 bits to represent one character, so it can represent some non-English character, common symbols and mathematical symbols

4 Big-5 A popular Chinese encoding system Big-5 character set contains traditional Chinese characters There are 408 symbols, 5401 are most commonly used characters and 7652 and 7,652 are secondary usage As one byte can represent 256 different combinations only Big-5 use 2 bytes to represent character combinations In order to avoid conflict with most commonly used computer encode, ASCII, Big-5 make the first byte as high byte and second as low byte

5 GB(Guo Biao) The common Chinese encoding system in China Use to represent Simplified Chinese GB character set contains 6,763 elements Similar to the design of Big-5, maybe confuse with ASCII meaning and display meaningless code

6 Unicode Under different platform, different software and different language, able to exchange every character over the world Character set should be large enough Each character has only one meaning

7 Reference Site