The personal-computer revolution is barely a decade old. Yet so perplexingly swift was its onslaught that already there is a spate of books detailing, in tones of awestruck veneration, the "early years" of the phenomenon and establishing a complete hagiography of its creators. Many of those names are now famous, including such entrepreneur-prodigies as the "St. Steves" (Wozniak and Jobs, of Apple), "St. Bill" (Gates of Microsoft) and other newsweekly darlings whose lads-to-riches stories make financially thrilling reading.

To date, however, authors have scanted the rest of the canon -- the eccentric programming wizards and circuit-board fanatics whose lonely midnight brainstorms made the technology that made the money. Understandably: Their work is arcane, cerebral, maddeningly hard to explain to laymen and inscrutable to humanists, and their habits creepy by normal standards. It is the triumph of Steven Levy's encomium that he makes these reclusive oddballs comprehensible, sympathetic and finally fascinating as a sort of highbrow "Revenge of the Nerds."

In a long series of cameo portraits, Levy traces a genealogy from the aboriginal hackers at the Massachusetts Institute of Technology in the late '50s through the semiconductor explosion of the '60s and the emergence of the microcomputer in the '70s, right up to the creators of today's best-selling software.

The term "hacker" derives from 30-year-old MIT jargon meaning a feat "imbued with cleverness, style and technical virtuosity." But from the eldest mainframe veteran to the latest pimpled whiz-kid, they are, Levy shows, an eerilyhomogeneous species: Young white males who "had grown up with a specific relationship to the world, wherein things had meaning only if you found out how they worked," whose most deliciously intimate moments are spent not with people -- and especially not women -- but with cybernetic devices. Often conspicuously deficient in social skills, they are possessed of a Faustian zeal -- "the idea was to burn away for 30 hours, reach total exhaustion, then go home and collapse for 12 hours," all fueled by Chinese food and, Levy suggests, displaced libido: "Hacking had replaced sex in their lives."

And all of them, Levy argues, share a highly evolved if tacit "hacker ethic" whose practice made the PC boom possible. Among its egalitarian precepts: that access to computers should be "unlimited and total"; that hackers should be judged by their work, not their age or degrees; that every system must be relentlessly improved for the good of all. To profit from those improvements is a betrayal because "all information should be free"; and since government and business wish to restrict that information, "Mistrust Yuthority -- promote decentralization."

Among the dozens of exemplars in Levy's roster, none embodies the credo so well as Ricky Greenblatt, the "archetypal hacker" from Columbia, Mo., who at age 9 was beating college students at chess and building his own electronic circuits -- "a world where there were no ambiguities." He entered MIT in 1962, picked up programming, and was soon driving the big mainframe with such magical ingenuity that mere courses became "irrelevant." So, it seems, did bathing; and "the joke around the computer lab was that there was a new scientific olfactory measure called a milliblatt."

He flunked out but hung around, hooked on the perfect lure for a shy misfit: "While a computer is very complex, it is not nearly as complex as the . . . interrelationships of the human zoo." The random messiness of life might force a fellow into a hundred humiliations, but "hacking gave you not only an understanding of the system but an addictive control as well, along with the illusion that total control was just a few features away." He became a legend for his pioneering programs, superhuman concentration and for giving hackers their first public victory: When a Rand Corporation academic scoffed in print that "no computer program would be able to play a good enough game of chess to beat a 10-year-old," Greenblatt wrote one that trounced the scoffing author himself in a public showdown.

Here also are Donald Woods of Stanford, creator of "Adventure," the prototype for Infocom's "Zork" series; Lee Felenstein, Robespierre of the Bay Area's computer-power-to-the-people movement and co-inventor of the Sol, precursor to the Apple personal computer; Ken Williams, whose Sierra On-Line became the hottest house in game software until its hacker ethic faded; his ace programmer, John ("Frogger") Harris, and dozens more.

Levy's warmth toward his subjects -- evident in the subtitle -- sometimes overheats his colorful prose, and at times the "hacker ethic" thesis gets downright Procrustean in making developments fit a pattern. But as an absorbing and instructive overview of a tough topic, "Hackers" is a huge job hugely well done.