The Blit (originally named the Jerq!) was an early graphical user interface, connected to a UNIX computer. Inspired by the Xerox Alto from the early 1970s, creators Rob Pike and Bart Locanthi wanted to make a graphics machine for use at Bell Labs that would have the usability of the Xerox, but with the processing power of a 1981 computer. Created using a Motorola microprocessor instead of a Bell one, the machine would be retooled for the commercial market (business market, because it was still expensive) as the AT&T 5620, which came out in 1984 — using a Western Electric WE32000 microprocessor. The Blit had a vertically-oriented display and an early mouse peripheral; this video explains how it worked.
Footage Courtesy of AT&T Archives and History Center, Warren, NJ