From 1906 to the 1970s, the Honeywell corporation grew from specializing in thermostats and home heating into military engineering, cameras and computing. James Warren Scarlett (1937-2016) was a team leader and electrical engineer at Honeywell through the crucial 1970s period where they led the world in developing process control technology for industrial plants. His records illustrate the development of Honeywell's Industrial Process Control Division's TDC 2000 and TDC 3000 systems. The collection has particular strengths in materials documenting the design of the user interface, sometimes referred to as the man-machine-interface (MMI). Materials include reports, papers, presentation slides, books, correspondence, and business cards.