Paritynonparity Check

Parity/Non-parity Check Early transmission codes had a serious problem in that a bit could be lost or gained in transmission because of an electrical or mechanical failure/ If the loss went undetected, the character received on the other end of the lime was incorrect. To Prevent this from happening, a parity check system was developed. Each character is represented by a byte consisting of a combination of intelligence bits (seven bits in ASCII and eight bits in EBCDIC) and an additional bit called a check or parity bit. Even parity codes place a check bit with each byte that contains an uneven number of 1 bits. (Remember that a bit is either 1 or o). Because the check bit is transmitted only with characters composed of an uneven number of 1 bits,all characters transmitted will have n even number of 1 bits. The check bit is transmitted to and from the computer along with character code.

If a bit is lost (or added) in transmission, the system will detect its loss. An uneven number of 1 bits received in a code string composed of even bits will signal an error. Odd Parity codes add a check bit to code combinations that have an even number of 1 bits. Thus,all characters transmitted have an odd number of bits. Odd and even parity care similar in nature.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

They are both designed to signal an error in the even that data are lost or added.