Abstract :
In the last 15 years, the speeds of the fastest central computer processors have increased at least 100 times, the speeds of peripherals have increased perhaps ten times, and the speed of the human users´ response to ihe computer´s challenge has not increased at all. These speed differentials will continue to pose difficult problems in the development of computer design and use. The continued rapid development of electronics equipment thus provides a sustained stimulus, but one that is subjected to mechanical and to human constraints.
