Was proclaimed “America’s most successful entrepreneur” by Fortune magazine in 1986, built Digital on $70,000 in seed money, founding it with a partner in 1957 in the small Boston suburb of Maynard, Mass. With Mr. Olsen as its chief executive, it grew to employ more than 120,000 people at operations in more than 95 countries, surpassed in size only by I.B.M. At its peak, in the late 1980s, Digital had $14 billion in sales and ranked among the most profitable companies in the nation. But its fortunes soon declined after Digital began missing out on some critical market shifts, particularly toward the personal computer. Mr. Olsen was criticized as autocratic and resistant to new trends. “The personal computer will fall flat on its face in business,” he said at one point. And in July 1992, the company’s board forced him to resign. Kenneth Harry Olsen was born in Bridgeport, Conn., on Feb. 20, 1926, and grew up with his three siblings in nearby Stratford. His parents, Oswald and Elizabeth Svea Olsen, were children of Norwegian immigrants. Mr. Olsen and his younger brother Stan lived their passion for electronics in the basement of their Stratford home, inventing gadgets and repairing broken radios. After a stint in the Navy at the end of World War II, Mr. Olsen headed to the Massachusetts Institute of Technology, where he received bachelor’s and master’s degrees in electrical engineering. He took a job at M.I.T.’s new Lincoln Laboratory in 1950 and worked under Jay Forrester, who was doing pioneering work in the nascent days of interactive computing. In 1957, itching to leave academia, Mr. Olsen, then 31, recruited a Lincoln Lab colleague, Harlan Anderson, to help him start a company. For financing they turned to Georges F. Doriot, a renowned Harvard Business School professor and venture capitalist. According to Mr. Colony, Digital became the first successful venture-backed company in the computer industry. Mr. Anderson left the company shortly afterward, leaving Mr. Olsen to put his stamp on it for more than three decades. After he left Digital, Mr. Olsen began another start-up, Advanced Modular Solutions, but it eventually failed. In retirement, he helped found the Ken Olsen Science Center at Gordon College, a Christian school in Wenham, Mass., where an archive of his papers and Digital’s history is housed. His family announced his death through the college. Mr. Olsen’s wife of 59 years, Eeva-Liisa Aulikki Olsen, died in March 2009. A son, Glenn, also died. Mr. Olsen’s survivors include a daughter, Ava Memmen, another son, James; his brother Stan; and five grandchildren.