SRI · San Francisco · 9 December 1968
The Mother of All Demos — 01 / 07
The Demo
Ninety minutes in which a thousand computer professionals saw the mouse, hypertext, windows and shared editing arrive as one working system.
01
One man, one console, no second take
The Fall Joint Computer Conference filled the Civic Auditorium. Engelbart sat alone on stage in a headset, his display projected twenty-two feet above him. The computer answering him was in Menlo Park, thirty miles away.
Two microwave links carried the picture down the peninsula and back; a leased line carried the keystrokes; a borrowed projector put it on the wall. Seventeen people ran cameras, mixers and cues at both ends. It was live, continuous and unrehearsed.
02
Six ideas, demonstrated together
The achievement was not any one of them, but that they arrived as one system, each making the others worth having.
- Pointing — a cursor tracking a hand across a desk.
- Linking — any word carrying an address to another document.
- Windows — the screen divided into independent, resizable views.
- Structure — every line belonging to a hierarchy you could operate.
- Shared editing — two people in one file, each with a visible pointer.
- Presence — a face and a voice sharing the screen with the document.
03
What a screen was in 1968
A computer display was a laboratory instrument: glowing vector strokes on a phosphor tube, priced in thousands. Most people who used a computer never saw one — they handed in a deck of cards and collected paper hours later.
Engelbart's argument was that a screen is not an output device. It is where thinking happens, and the pointing, the linking and the structure all follow from taking that seriously.
The recording still exists
All ninety minutes were filmed, and the film survives — slower than a modern launch, and stranger than most science fiction.