PALO ALTO, CALIF., JUNE 4 -- Silicon Valley, the world's technological heartland and the symbol of America's postwar economic dominance, lay stunned today, not just by the death of Robert Noyce, the man who started it all, but by the realization that these are the closing moments of a glorious era.

It is far more difficult today to do what Noyce and his compatriots did so well about 30 years ago -- take a bright idea, add to it unabashed ambition and, on the fringe of an apricot orchard, create an industrial revolution.

Noyce did nothing less. As the co-inventor of the integrated circuit, he has been likened in stature to ThomasEdison and the Wright brothers -- a man who made possible the electronic age by connecting transistors on a tiny silicon chip.

"It's the key invention of the 20th century," said National Science Foundation Director Erich Bloch, "because it impacts everything, from education to products ... and the way we deal with each other in society at large."

More than a tinkerer, Noyce became a symbol of the modern American entrepreneur, a time when people got rich and famous with brains, not boastfulness.

It is something of an irony that Noyce's death on Sunday came on the very day that Soviet leader Mikhail Gorbachev arrived in the San Francisco Bay area to pay symbolic tribute to the raw spirit of capitalism that still thrives here like nowhere else.

But the Robert Noyces of the world no longer can roam as freely as he did. "Noyce's death signals the end of an era," said Michael S. Malone, the author of a book chronicling Silicon Valley history. "What he created -- the modern electronics industry -- has become so sophisticated that the kind of Wild West style which he helped create is gone."

In fact, the latter part of Noyce's life symbolized the realization that lone cowboys rarely succeed in a period of strong international competition. A frequent visitor to Capitol Hill and the premier voice for an embattled U.S. electronics industry, Noyce called for a stronger government role in tax, trade and industrial policy to benefit his industry -- much in the model of the Japanese policies he so roundly criticized.

At the time of his death, Noyce was the head of Sematech, an industry-government research consortium in Austin, Tex., that represents the newest era in U.S. industry -- the drive not just to compete, but to cooperate.

Noyce was never one to follow convention. The son of an Iowa preacher, he was once thrown out of school for stealing a pig from a farm for roasting at a luau. An avid scuba diver, pilot and skier, the streak of daredevil stayed with him for life.

William Davidow, who worked with Noyce at Intel Corp. -- one of two firms co-founded by Noyce -- recalls a Canadian Rockies ski trip a few years back when Noyce delighted in skiing over a 25-foot cliff. "I never understood why he thought he was going to jump off it. He just decided he was going to do it."

That sense of adventure led Noyce and seven others in 1957 to desert Nobel Prize winner William Shockley and seek financing for their own firm, Fairchild Semiconductor. In so doing, they inspired hundreds of other bright entrepreneurs whose breakaway spirit, backed by what has come to be known as "venture capital" investors, spawned Silicon Valley.

Noyce's emergence as an industry statesman began long before many others recognized the consequences of growing international competition. It was a decade ago that he began trips to Washington, warning about matters that would later become topics of widespread concern -- closed markets for U.S. imports, particularly in Japan and Europe; attempts by Japanese firms to "dump" chips; Japanese efforts to target specific industries for government support in ways that made it tough for U.S. firms to compete against them.

In his latter years, in fact, he seemed almost bitter and became openly critical of Japanese industry to the point that some people grew uneasy with his bluntness.

As Sematech chief, his calls for government intervention to halt foreign acquisitions of key U.S. technologies drew criticism from some in Silicon Valley who say the days of the strike-it-rich entrepreneur are still alive and well.

Attracted by his laser-sharp mind and gracious manner, people flocked to Noyce. It could be disarming talking with the man. He would listen intently, then respond with an uncanny deep voice, a piercing gaze, a broad smile and a logic that was hard to refute.

Noyce never sought the fame he earned. Rather than sign autographs at a dinner honoring him, he would ask others for theirs. Small projects done by low-level engineers would elicit written praise from Noyce.

And at Intel, he helped pioneer the egalitarianism that has now become a fixture of modern management -- for executives, there were no special parking places, no limousines and no offices, only open cubicles.

Noyce's colleagues say he didn't have to brag; his intellect and gentlemanly manner instantly drew respect. Tom Wolfe, in a 1983 Esquire magazine profile, described him this way: "Bob Noyce projected what psychologists call the halo effect. People with the halo effect seem to know exactly what they're doing and, moreover, make you want to admire them for it."