Data Representation & Character Encoding

• Denary is a base-10 number system with 10 digits, each of which is represented by a digit from 0 to 9. It is the most common number system used in human communication.
• Binary is a base-2 number system which solely consists of digits 1 and 0, which reflects the on and off states of a transistor.
• The bit depth reflects the number of binary numbers available. Some examples with this include image and audio files.
• An overflow error is caused when the processor does not have enough bytes available to process an instruction.
• Hexadecimal is a base-16 number system which is used to represent binary numbers in a compact form for documentation purposes.
• Applications of Hexadecimal:

  • Colour references
  • Assembly language programs
  • Error messages
• 1 hexadecimal digit is equivalent to 4 binary digits.
• ASCII (American Standard Code for Information Interchange) was devised for early telecommunication system but proved to be ideal for computer systems and forms the basis for almost all other character sets.
• Unicode is a character coding system designed to support the worldwide interchange, processing, and display of the written texts of the diverse languages and technical disciplines of the modern world.
• ASCII is a 7-bit character set with 128 different characters while Extended ASCII is an 8-bit character set with 256 different characters.
• Unicode is a 16-bit character set which aims to be able to represent any possible text in code form. However, it takes up more memory space than ASCII and is designed in such a way that once a character has been defined it is never changed.