such that he was kept busy with improvements to his Programmed Data Processor productline, attempting upward compatibility from the PDP-1 onwards, producing the highly successful PDP-8, and PDP-10. One of his chief engineers, Edson de Castro, left after failing to get permission to design a 16-bit version of the 8-bit PDP-8 and founded Data General. Both men then competed to create a 32-bit version. This competition is well documented in the book The Soul of a New Machine by Tracy Kidder. The VAX became the cash cow for Digital Equipment, and the successful collaboration with Xerox and Intel on the introduction of a local area network solution called Ethernet resulted in a decade of successful growth for the company. References The ultimate entrepreneur: the story of Ken Olsen and Digital Equipment Corporation entry in Google Books, by Glenn Rifkin, George Harrar, 1988, Chicago : Contemporary Books, The Soul of a New Machine entry in Google Books, by Tracy Kidder, Reprint from 1981, Back Bay Books, 2000. 1988 non-fiction books Computer books Digital Equipment Corporation