for Visual Technology. They made DEC and Tektronix 4xxxx-series compatible terminals. Their terminals emulated various companies and their V-4xx series were their color graphics line. These had two Z80 processors in them; one each to support either the color graphics side or the text-side of the terminal. Their V-550s were graphics and text, but only had one processor.
The hardware was fun to work on and I learned a lot about digital logic, RAM, and cpus by working on these boards.
Keep Up with TechRepublic