04 / 07
The Mother of All Demos
SDS 940 · Menlo Park · 192 kilobytes
The Machine
Everything on the screen that afternoon ran on less memory than a modern web page's fonts.
A Scientific Data Systems 930, the machine family that ran NLS. CC BY-SA 4.0.
01
The memory
192 kilobytes, shared by everyone
NLS ran on a Scientific Data Systems 940 at Menlo Park, with 192 kilobytes of core memory shared across every user at once. Plug-in circuit cards on one side of the cabinet, core memory on the other — every bit of it a hand-threaded ferrite ring.
A machine of this class cost, in 1968 dollars, more than a house.
The Augmentation Research Center at work. Photograph: SRI International, public domain.
02
The link
Thirty miles of link
The picture travelled by two microwave links down the peninsula and back. The keystrokes travelled by leased line. None of it was productised; all of it worked, for ninety minutes, in front of a thousand people.
An NLS workstation at SRI in 1968 — mouse at the right hand, keyset at the left. Photograph: SRI International, CC BY-SA 3.0.
Constraint was not the obstacle
The ideas were never waiting on hardware. They were waiting on someone to take the screen seriously.
The future
was shared.