The world of architecture and engineering before AutoCAD demanded serious dedication, but as computing systems advanced, it was inevitable that technical drawing and computers would cross paths. In 1963, Ivan Sutherland — “the father of computer graphics” — unveiled Sketchpad, a pioneering program in human-computer interaction, the first with a complete graphical interface, and one of the most compelling arguments for adopting the light pen.
Many of our readers probably remember Spacewar! one of the most important video games in history. Spacewar! ran on a PDP-1, DEC’s first computer, based on two earlier developments: the Lincoln TX-0 (which we mentioned in our post about the Tech Model Railroad Club) and the Lincoln TX-2, essentially a “downscale” of the extremely ambitious TX-1 that was never built.
Spacewar! and the PDP-1 demonstrated the potential of graphics and computers for entertainment, but on the productivity front, there was a development as revolutionary as Spacewar!, or even more so. Its name was Sketchpad, and it could do this:
The TX-2 had been specially designed to advance human-computer interaction, and Sketchpad was one of the most impressive “demos.” Created by Ivan Sutherland, Sketchpad squeezed every aspect of the computer: its programmable buttons, its oscilloscope screen, the light pen (invented in the ’50s), and a plotter as an output device.
In the video, you can appreciate the extraordinary precision users achieved in Sketchpad by combining physical buttons and the light pen: indicating vertical and horizontal positions on lines, creating arcs with ease, forming dashed lines to identify gaps, and changing the dimensions of parts almost in real time.
That’s the key: while other programs worked in batch mode, Sketchpad was completely interactive.
Sketchpad wasn’t too hard to learn, but thanks to its extensive list of parameters (vertical, horizontal, parallel, identical size, etc.), users could develop very advanced projects from a simple sketch.
You didn’t even have to enter correct dimensions or draw straight lines: a couple of buttons and a simple tap of the light pen dynamically corrected the piece in question. The best part? Sketchpad could be extended, and after Sutherland’s presentation (who was recognized with the Turing Award in 1988 and the Kyoto Prize in 2012), Timothy E. Johnson and Lawrence G. Roberts published two 3D variants—one wireframe and one for solids.
What inspired Sutherland to create Sketchpad? Nothing less than Vannevar Bush’s famous Memex, one of the foundational stones of hypertext.
Source: Sketchpad – Ivan Sutherland
