A parametric graphical display technique for on-line use

Graphical displays are gaining unquestioned importance in the growing field of communication between man and digital computers. The development of time-shared digital computers further accentuates the need for widely-used graphical interaction within the framework of certain economic constraints. Typically, these constraints involve the use of relatively low telephone-channel data rates, and the temporary storage of graphical data at the display site. User requirements dictate both an input and output ability of alphanumeric and graphical data for typical applications. A typical time-shared application, which gave rise to the technique and prototype described in this paper, involves the online design of electronic circuits. Here, a designer communicates graphically a circuit to the computer, visually observes circuit-analysis results in the form of curves, and modifies on-line circuit parameters and topology in order to improve circuit performance.