A method of data transfer between a computer and a peripheral unit where data are transmitted for input to the computer or output to the unit bit by bit over a single circuit.; 一種計算機與外圍設(shè)備間傳送數(shù)據(jù)的方法,數(shù)據(jù)向計算機輸入或向外圍設(shè)備輸出是經(jīng)一條線路逐位傳送的。