Section 4.1
4 Data Representation
4.1 Different Computer Codes
Over the years different computer programmers have used different sets of codes
to represent different characters.
Most computers use 8-bit codes to represent each character.
This is enough to allow a unique code for each character with one bit spare.
This spare bit can be used in one of two ways:
- as a parity bit.
- to represent an extended character set.
Most micro-computers use ASCII, but some larger systems might use EBCDIC (Extended
Binary Coded Decimal)
Parity
Computers use either Odd Parity or Even Parity to detect errors.
In an even parity machine, the total number of 1s must be an even number.
