Abstract :
Graphic terminals allow on-line interaction between the user and his program, thereby enabling him to alter the displayed picutre according to his requirements. However, a major problem with the use of a graphic terminal is the cost associated with it. There is no doubt that low-cost graphic terminals are available, but their utility is very limited since they have no processing capability (or intelligence) and must depend on a host processor attention, while at the same time putting additional strain, on the resources of the host machine. This naturally degrades the response time, depending on the processor load at that time, On the other hand, graphic terminals which have local processing capability are very expensive. With the availability of microprocessors, it is now possible to resolve this delemma: a reasonable amount of intelligence can be added to the terminal at a very reasonable cost. Such a terminal has been developed at the University of Ottawa.
