By Mary Bellis
I came to work one day at MIT and the computer had been stolen, so I called DEC to break the news to them that this $30,000 computer that they’d lent me was gone. They thought this was the greatest thing that ever happened, because it turns out that I had in my possession the first computer small enough to be stolen! – Robert Metcalfe on the trials and tribulations of inventing the Ethernet.
The ethernet is a system for connecting computers within a building using hardware running from machine to machine. It differs from the Internet, which connects remotely located computers by telephone line, software protocol and some hardware. Ethernet uses some software (borrowed from Internet Protocol), but the connecting hardware was the basis of the patent (#4,063,220) involving newly designed chips and wiring. The patent* describes ethernet as a “multipoint data communication system with collision detection”.
Robert Metcalfe was a member of the research staff for Xerox, at their Palo Alto Research Center (PARC) where some of the first personal computers were being made. Metcalfe was asked to build a networking system for PARC’s computers. Xerox’s motivation for the computer network was that they were also building the world’s first laser printer and wanted all of the PARC’s computers to be able to print with this printer.
Robert Metcalfe had two challenges: the network had to be fast enough to drive the very fast new laser printer; and it had to connect hundreds of computers within the same building. Never before had hundreds of computers been in the same building — at that time no one had more than one, two or maybe three computers in operation on any one premise.
The press has often stated that ethernet was invented on May 22, 1973, when Robert Metcalfe wrote a memo to his bosses stating the possibilities of ethernet’s potential, but Metcalfe claims ethernet was actually invented very gradually over a period of several years. In 1976, Robert Metcalfe and David Boggs (Metcalfe’s assistant) published a paper titled, “Ethernet: Distributed Packet-Switching For Local Computer Networks.”
Robert Metcalfe left Xerox in 1979 to promote the use of personal computers and local area networks (LANs). He successfully convinced Digital Equipment, Intel, and Xerox Corporations to work together to promote ethernet as a standard. Now an international computer industry standard, ethernet is the most widely installed LAN protocol.
* U.S. Patent #4,063,220 – Ethernet Patent
Multipoint data communication system with collision detection.