INVESTIGATION OF THE EFFICIENT CONNECTION OF VERY HIGH SPEED GRAPHICS TERMINALS TO A LARGE SCALE COMPUTING FACILITY

摘要

The evolution of interactive computer graphics terminals and the systems used to support them are outlined. A rationale is given for data communication speeds out to the terminals of 50,000 bits/sec. Computer data communications systems can be classified according to the amount of information transferred per CPU interrupt. Such systems have been broken into three categories: character-at-a-time, line-at-a-time, and disk sector-at-a-time. The characteristics of each is given and the conclusion is drawn that for the postulated system of thirty interactive graphics terminals, the disk sector-at-a-time approach is the one that has the best chance of meeting requirements of high speed, network capabilities, and minimum mainframe system modification, all the while at reasonable cost. Data communication systems at the University of Michigan (line-at-a-time) and Purdue University (disk sector-at-a-time) are studied in detail.