In an information processing system comprising a central processing unit, an input/output unit and a first-in first-out stack connected between these units there are provided a buffer control circuit for detecting the full and empty states of the first-in first-out stack, an input/output control circuit...http://www.google.com.tw/patents/US4062059?utm_source=gb-gplus-share專利 US4062059 - Information processing system
