A Microprogrammed Intelligent Graphics Terminal

This paper describes a small computer, Interdata Model 3, that has been microprogrammed to serve as an intelligent terminal. The Interdata is connected to a System/360 multiplexor channel with a high-speed interface, and uses an ARDS direct view storage tube as a display console. The new Interdata target machine is patterned after the /360 (including all five instruction formats), but also has instructions particularly designed for intelligent terminal programming. These include instructions for character string manipulation, code conversion, list processing, coordinate manipulation, and virtual addressing. A powerful multiplexor channel, which allows the programmer to "overlap" I/O to several devices with a CPU program, has also been microprogrammed.