John Ellenby, a British-born computer engineer who played a critical role in paving the way for the laptop computer, died on Aug. 17 in San Francisco. He was 75.
His son Thomas confirmed the death but said the cause had not been determined.
Mr. Ellenby's pioneering work came to fruition in the early 1980s, after he founded Grid Systems, a company in Mountain View, Calif. As chief executive, he assembled an engineering and design team that included the noted British-born industrial designer William Moggridge.
The team produced a clamshell computer with an orange electroluminescent flat-panel display that was introduced as the Compass. It went to market in 1982. The Compass is now widely acknowledged to have been far ahead of its time.
"The Grid Compass was the first successful clamshell laptop computer," said Marc Weber, a historian at the Computer History Museum in Mountain View.
It went on to become a valuable tool for big corporations, government spies, White House and Pentagon officials, and even astronauts, surviving the midair explosion of the space shuttle Challenger in which seven people died.
The Compass came with advanced, and expensive, data storage capacity called bubble memory and was accordingly pricey, originally selling for $8,150 ($20,325 today). As a result, it found an enthusiastic market not with consumers but rather in Washington.
One version, intended for United States special-operations forces, was said to have come with a red dot on its black magnesium case, placed there as an aiming guide for any commando who might have to shoot the device to destroy its data quickly.Intelligence agencies were also eager buyers; the Compass was marketed as a kind of sexy, high-tech device that might appeal to James Bond.
Another user was Vice Adm. John Poindexter, President Ronald Reagan's national security adviser in the mid-1980s. Admiral Poindexter, a computer hobbyist, would take the laptop with him when Mr. Reagan traveled. He would also spend his free time using the Compass to reprogram the IBM electronic mail system that the White House employed, according to James Opfer, who was director of the White House Communications Agency then and who arranged the first White House purchase of the machines, for $2 million.
Mr. Opfer said in an interview that he was "90 percent certain" that for a time, a Compass accompanied the president's ever-present "nuclear football" - the device, carried by a military aide, that makes it possible to launch nuclear weapons. "It was quite heavy," he recalled.
Admiral Poindexter, also in an interview this week, remembered the Grid computers as "really nice machines" that had been "built like an armored tank." He said that he and Robert C. McFarlane, who preceded him as Mr. Reagan's national security adviser, had each kept Mr. Reagan's Compass locked in a home safe.
NASA also used one as a backup navigational device in its space shuttle program. One was aboard the Challenger on the morning of Jan. 28, 1986, when a rocket-booster failure destroyed the craft shortly after liftoff from Cape Canaveral in Florida. The Compass, which had been attached to a dashboard with Velcro, was recovered from the debris and found to be still working.
John Ellenby was born in Corbridge, in northern England, on Jan. 9, 1941, to Conrad Ellenby, a zoologist, and the former Mary McCarraher, a biologist. He studied economics and geography at University College London and spent a year in the early 1960s studying at the London School of Economics, where he encountered mainframe computers.
He later worked for the British computer maker Ferranti and lectured on computing at the University of Edinburgh in Scotland. He moved to Northern California in the early 1970s to work for the Xerox Corporation at its Palo Alto Research Center.
At the time, Xerox was designing a desktop computer, known as the Alto, which would become an inspiration for the Apple Lisa and Macintosh, and for Microsoft Windows. Inside Xerox, the Alto was known as an "interim Dynabook," a reference to the prototype for a portable machine envisioned by the Xerox computer scientist Alan Kay. ©The New York Times
Mr. Ellenby was instrumental in managing the development of the Alto II, a version of the prototype that could be manufactured more easily. He had earned a reputation as a technologist who was adept at turning technologies into products.
"He was good and aggressive and even daring, you might say," said David Liddle, a Xerox executive at the time.
Mr. Ellenby left Xerox to found Grid in 1979. The move paid off. In addition to his government customers, corporations like Bank of America, Chevron and McKinsey & Company were early buyers.
Mr. Weber, the computer historian, said that the name Grid was derived from Mr. Ellenby's vision of a gridlike network - a precursor to the internet - that would connect various computers with one another, allowing them to share files. The idea was to sell the system through a business services company. The company called the system Grid Central.
Initially the Compass was so energy-hungry, it required a plug. And the machine took competitors by surprise. One was Adam Osborne, the developer of the Osborne 1, an early portable computer - a "luggable," in industry parlance - about the size of a sewing machine. Appearing with Mr. Ellenby on an industry panel, Mr. Osborne was startled to realize that the device sitting flat on a table nearby was, when it was opened, a portable computer.
Mr. Ellenby sold Grid to the Tandy Corporation in March 1988. He went on to start Agilis, a maker of hand-held tablet computers, and, with his son Thomas, GeoVector, which pioneered navigation and augmented-reality applications.
(Mr. Moggridge, who died at 69 in 2012, went on to help found Ideo, one of Silicon Valley's leading industrial design firms, and to be named director of the Cooper Hewitt design museum in New York.)
In addition to his son Thomas, Mr. Ellenby is survived by another son, Peter, and a granddaughter.
In his later years, Mr. Ellenby would reflect on what a huge technical challenge the idea of a portable computer had presented a half-century ago. In an interview, he once related that the inspiration for it came on a visit to the White House.
There, he met an official who said he wanted a machine that would include everything that was in a standard business personal computer but that would fit in half the briefcase that Mr. Ellenby was carrying with him at the time. As Mr. Ellenby recalled, "I said: 'This briefcase? That's hard!'"
