Anyone who has ever worked at Data General might be inclined to believe the very first LAN technology to emerge was ARCNet. Indeed, ARCNet was invented by John Murphy and introduced by Data General in December 1977, while its apparent primary rival, Ethernet, was only unveiled by Xerox Palo Alto Research Centre (PARC) in 1979.

But all is not as it seems. Although it was only released for external use - and licensing - in 1979, Ethernet had, in fact, been in regular use within Xerox shortly after its invention by Robert Metcalfe and David Boggs more than four years earlier. This is according to Roy Allan, writing in his catalogue of the people and technologies involved in A History of the Personal Computer.

Origins of the ethernet