On 22 May 1973, Robert Metcalfe crafted a memo on an IBM typewriter that outlined an “Ethernet” network of coaxial cables as way to connect computers and printers.
If Ethernet was invented in any one memo, by any one person, or on any one day, this was it.
Metcalfe was a researcher at Xerox Palo Alto Research Center in California. His task: develop a way to connect hundreds of Xerox Altos computers (the first personal computer) in the same building. They would share the Xerox EARS, the first laser printer.
It’s hard to visualize this today, but computers had just gotten small enough that there could be hundreds of them in one building!
Metcalfe didn’t base the name ethernet on the anesthetic that puts people to sleep. It refers instead to a discredited scientific theory of the luminiferous aether, an undifferentiated universal medium that some 18th- and 19th-century scientists thought necessary for the propagation of light. Metcalfe saw it as an apt metaphor for a medium that would propagate information.
The system began running on 11 November 1973.
Over the next few years, Metcalfe worked on the protocol. In 1976, he and his assistant David Boggs published Ethernet: Distributed Packet-Switching for Local Computer Networks.
Metcalfe would leave Xerox and found 3Com (“computers, communication, compatibility”) in 1979.
He successfully convinced the Digital Equipment, Intel and Xerox corporations to work together to promote Ethernet as a standard. He succeeded as Ethernet is now the most widely-installed LAN protocol and an international computer industry standard.
And yes, Ethernet remains an important technology, almost 50 years later. Ethernet networks power the data centers that power the Internet.