Mr. Perkins was been partner of Kleiner Perkins Caufield & Byers, a venture capital company, since 1972 and one of the firm's co-founders. Mr. Perkins and his partners popularized a model of investment that involved putting small amounts of money into promising young start-ups in return for a stake in the companies, giving them advice and counsel to spur their growth. Some of the investments turned into gigantic hits. Mr. Perkins had said that his favorite investment was Genentech, a biotechnology company that has since been acquired by Roche. Over time, Kleiner Perkins — and its home on Sand Hill Road in Menlo Park, Calif. — became a destination for other venture capitalists. Thomas James Perkins was born on Jan. 7, 1932, and grew up in White Plains in modest circumstances, attending White Plains High School. His father, Harry, worked for an insurance company, and his mother, Elizabeth, was an occasional seamstress. He became interested in technology early. Accepted to the Massachusetts Institute of Technology, he studied electrical engineering and computer science, earning his bachelor’s degree in both. He later received an M.B.A. from Harvard Business School. After working for a time for Sperry Gyroscope Company in Great Neck, on Long Island, he moved to California, where he worked in the technology industry for a decade He joined H.P. in the 1960s, working for the company’s founders, David Packard and William Hewlett. When Mr. Perkins and Eugene Kleiner founded Kleiner Perkins in 1972 (Mr. Byers and Mr. Caufield joined later), Silicon Valley knew little of venture capital, and the men had the field largely to themselves, investing in fledgling companies like Tandem Computer, Applied Materials and Genentech. Mr. Perkins later stepped away from active venture investing and joined several corporate boards over the years, including Compaq Computer and News Corp. Compaq was purchased by H.P. in 2001, and Mr. Perkins joined H.P.’s board in 2005, not long before its chief executive at the time, Carly Fiorina, was fired. Mr. Perkins supported Ms. Fiorina’s recent run for the Republican presidential nomination. Before his marriage to Danielle Steel in 1998, Mr. Perkins was married to Gerd Thune-Ellefsen, a Norwegian whom he had met skiing near Lake Tahoe, until her death in 1994. He is survived by two children from that marriage, a son, Tor, and a daughter, Elizabeth.