Dealers of Lightning: Xerox PARC and the Dawn of the Computer Age

by Michael A. Hiltzik

Over the next few months Metcalfe worked to adapt it to the center’s high-volume, high-performance specifications. He junked the central control computer, Menehune, because each Alto would control its own transmission rate. He designed a scheme by which each station would listen to the line and stop transmitting the instant it heard any interference, instead of continuing to chatter. And rather than transmit via radio, he proposed joining the Altos by some sort of physical line. The key element was that the medium had to be inert. Metcalfe understood that if the line had to carry an electrical current to aid transmission, like a phone line, Murphy’s Law would take over. The line voltage would become the component most vulnerable to failure. But if there was no power on the line, Murphy would be defeated. It was possible and much better, he reasoned, to send messages into a passive medium, like the “‘luminiferous aether’ once thought to pervade the universe as the medium for the propagation of light.”