Poster for The Mother of All Demos

A poster announcing Engelbart's demo on 9 December 1968 as part of the ACM/IEEE Fall Joint Computer Conference in San Francisco. Photo by SRI International via the Doug Engelbart Institute

—Eric S. Hintz

This is a flyer for the demonstration Dr. Douglas Engelbart conducted in Menlo Park at the Stanford Research Institute (SRI) showing a computer that presages the systems available decades later with networks, links, files, copy/paste, and even a mouse.

The event was important not only for what was demonstrated, but how it was demonstrated.

The ARC team, led by Bill English, spent months assembling a custom infrastructure so that Engelbart could stand on-stage in San Francisco and demonstrate the capabilities of the NLS located 30 miles away at SRI’s offices in Menlo Park. They placed cameras in front of two NLS monitors at SRI, erected receiver dishes at the auditorium, and beamed two channels of video along a microwave link. Two more cameras in the auditorium captured Engelbart’s face and hands as they manipulated the keyboard, mouse, and chord keyset. Finally, the team rigged up a homemade 2,400 baud modem to transmit commands from Engelbart’s console in San Francisco back to Menlo Park over a leased telephone line. English used a 4-channel video controller to direct what was projected on the auditorium’s 20-foot screen; he could also split the screen and show, for example, Engelbart’s face alongside his NLS screen. Altogether, 17 ARC teammates contributed to the demo.

—Eric S. Hintz