Asynchronous transmission system, particularly for a videotext interactive system

摘要

A videotex asynchroneous transmission system uses a parity bit for each character, with a continuous ARQ-type retransmission method. The data are transmitted in blocks (so-called "code words"). Each code word is comprised of a block of seventeen bytes "1"-"15" constituting the characters which are to be transmitted encoded by seven bits b1-b7. The 8th bit b8 of each byte is the parity bit. The 16th byte is the check byte of the code word, and the 17th byte being the enabling byte of the code word.