The board boasts full graphical compatibility with the Tektronix 4010 and featured the ability to plot individual points on the screen as well as solid, dotted, and dashed lines based on vector instructions, as well as the ability to selectively erase portions of the screen and change the size of text characters on the fly.
[2] An optional light pen allows the VT100 with the VT640 board installed to emulate the 4010 in the latter's graphic input mode.
[1] Digital Engineering reportedly sold millions of dollars worth of the VT640 and other Retro-Graphics products within the first year of availability.
[1] A large institutional user of the VT640 in 1983 was the Los Alamos National Laboratory (LANL), who retrofitted 200 of their VT100s with VT640 boards.
[3] Another large customer of the VT640 was the Lockheed Missiles and Space Company, who used it to display the output of interferometers during mechanical stress and strain measurements conducted on the materials used as the skin of their aircraft.