Sketchpad and the Light Pen

JAN 15 1963 · 12:00

Lissajous figures tracing on a CRT. Sketchpad ran in 1963 on a 7-inch oscilloscope tube wired to the TX-2 mainframe. Place: MIT Lincoln Laboratory, Lexington, Massachusetts Figures: Ivan Sutherland, 24, doctoral candidate · Claude Shannon, thesis advisor · Marvin Minsky and Steven Coons, thesis committee · the TX-2 mainframe Ivan Sutherland defends his PhD thesis at MIT in January 1963. The artifact: Sketchpad, an interactive graphics program running on the TX-2 mainframe at Lincoln Lab. The user draws with a light pen directly on the CRT. The system snaps lines to constraints, infers rectangles from rough sketches, lets the artist define a master shape and instance it across the canvas. Object-oriented graphics, vector primitives, and constraint solvers all arrive in one 88,000-word document. The hardware is hardly portable. The TX-2 fills a room. The CRT is a 7-inch military-surplus oscilloscope tube. The light pen is wired with a thumb-switch. None of this matters. The interaction model, the artist pointing AT the image and the image responding, is the conceptual ancestor of every painting program, every CAD package, every photo editor, and every web-canvas tool that the next sixty years will produce. Video: The 1963 demonstration film of Ivan Sutherland's Sketchpad running on the TX-2 at MIT Lincoln Lab.