storage. RAM memory typically incorporates a parity checker on board. RAID uses
parity as one method of safeguarding data integrity.
Let X be an input string. An even parity checker outputs the value 1 if X contains an odd
number of 1’s in the input X. The checker outputs the value 0 otherwise.
Before the invention of Unicode, ASCII was the standard representation of characters. In
the ASCII system, there are in total 128 characters (including digits, letters in uppercase
and lowercase, punctuations and selected special characters). Table 1 shows the printable
ASCII characters (excluding whitespace) that are recognized by MARIE. Each character
has 7 bits. When the characters are stored on a disk or transmitted across a network, a
parity bit may be added to the end of each code to make up for 8 bits.