THE PERSONAL COMPUTER phenomenon is scarcely 0 years old, yet the early days of the industry are already being viewed with the kind of awed reverence usually accorded to, say, the Treaty of Ghent.

Such hasty veneration may seem premature even in the frantic pullulation of modern life, where the electronic dernier cri changes so often it has become one long howl of techno-shock. But the lessons to be learned from these three overview volumes could not be more timely or more intriguing as the nation ponders its economic future and the all- transforming purport of the PC revolution.

Chief and most heartening among those lessons is the triumph of individual ingenuity -- the overriding theme of Fire in the Valley, a history of the microcomputer boom from the first silicon chip to the IBM PC told in brisk prose and serial vignettes.

Despite the present multi-billion-dollar scope and Fortune- 500 luster of the personal-computer industry, its originators were a motley congeries of dreamy misfits, nerds and zealots working alone in garages or spare rooms, sharing ideas through hobbyist groups like Menlo Park's Homebrew Computer Club and obscure periodicals like Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, trading information without concern for competition.

Fire is at its best in catching the aura of those early years, in which breakthroughs often seemed fortuitous. Ed Roberts was urged to develop the first successful micro because Popular Electronics magazine wanted a cover story to top its rival, Radio Electronics. (Roberts missed the deadline, and the Jan. 1975 issue "featured a flashy cover photo of an empty metal box masquerading as a computer.") Even the brand name arrived by accident. Stumped for a snazzy title, Roberts asked his 12-year-old daughter, who was watching Star Trek: "Why don't you call it Altair," she said. "That's where the Enterprise is going tonight."

The industry, meanwhile, was going through the ceiling. By the beginning of 1976 dozens of companies were starting, expiring and reforming in the mad flux of development; and Fire offers abundant portraits of those who prevailed: a wimpy teenage hacker named Bill Gates (now head of giant Microsoft) who created the first BASIC language for the Altair; Prof. Gary Kildall (founder of Intergalactic Digital Research, which later lost the first adjective) whose first commercial project was a horoscope program and whose CP/M operating system became a universal standard; Seymour Rubinstein, a ruthlessly cunning negotiator who started MicroPro and made a fortune on WordStar; and a score more.

The book's chapters are arranged by topic but proceed chronologically. This scheme leads to some redundancy; and by 1980, the onrushing press of events proves too heavy for the format and the smooth narrative yields to a choppy incoherence. But Fire -- lavishly illustrated with photos -- is an inspiring testament to solo genius and determination, and to what the authors, both veteran computer journalists, call a "computer-power-to-the-people spirit" that would survive the industry's engulfment by big business.

It was a surprisingly long time coming. As Salomon Bros. analyst Stephen T. McClellan argues in his brutally outspoken study, The Coming Computer Industry Shakeout, most of the big outfits -- through a combination of short-sightedness, inertia and the difficulty of modifying large-scale manufacturing operations -- simply ignored the trend toward smaller machines until it was too late. A conspicuous exception: IBM, which the author safely predicts will dominate the market in the '80s.

But woe to those other companies which "allowed themselves to stay flabby too long and lost their ability to react quickly." The fast-money days are over, and "even though the pie is getting bigger," the "slices are getting thinner and thinner." Survivors must combine ingenious market anticipation, manufacturing flexibility and careful debt management while ceaselessly encouraging creative research efforts which are too easily smothered by bureaucracy. It's a delicate balance, the lack of which, McClellan predicts, will cause a major shuffle in the top 10 computer firms by 1990. Dropping off the list: Sperry, Honeywell, Xerox and Memorex. Coming on: Wang, Electronic Data Systems, AT&T and the dreaded "Japan, Inc." (Though McClellan says that the industry is evolving so fast here that there is "really no reason to worry" about Toyota Syndrome in the near future.) He is also bullish on many smaller companies like Tandy and Tandem.

Though Shakeout is intended primarily for potential stockholders, it is of equally urgent interest to those who are about to buy computers of any size. Most of the book is devoted to a company-by-company analysis of the mainframe, minicomputer and micro markets, interspersed with McLellan's unabashed prognostications. Among them:

"Computers will become the single most valuable resource in the United States" and the industry so "diffuse" that "it will belong to everyone." Yet most of today's hot, mid-size "insurgent" companies will not survive.

Apple Computer "is experiencing serious problems" as IBM hogs 45 percent of the personal-computer market (growing, McClellan says, by 50 percent a year), and can only be rescued by huge sales of the Macintosh, which McClellan says is "slick" but "dosn't make it" as a home or business machine.

Software is "the No. 1 computer business of the future", and the Unix operating system will soon become the national standard.

Readers mainly interested in personal computers -- and newly wary following the debacles at Osborne and Atari -- may find McClellan's treatment of the micro market too brief and his discussion of software houses particularly skimpy; and his trope-laden prose style too often sounds like a drunken sports writer. But Shakeout, which ends with 15 practical "McClellan's Laws" for industry watchers (e.g.: "Call the company at 8:30 A.M. or 5:30 P.M. and see if anyone is there"), will benefit anyone planning to invest in this frenzied business.

No story exemplifies that frenzy as clearly as the history of Apple Computer, the subject of The Little Kingdom by Time financial reporter Michael Moritz. It began in 1971 with two Silicon Valley boys who would form the oddest pairing since Laurel and Hardy: Stephen Wozniak -- a prototypical computer nerd and practical joker with a brilliant intuitive understanding of circuit design -- who was building his own personal computer in his garage; and Steven Jobs, a melancholy loner fond of drugs and drawn to Eastern philosophies who believed that a fruit diet made showers unnecessary, traveled to India for spiritual truth, took primal scream therapy and teamed up with Woz to make and sell "blue boxes" which cheated the phone company by tapping into trunk lines.

Both kicked around in a number of firms, and Woz built another small computer which he offered to his then-employer, Hewlett-Packard. HP demurred and Woz was going to give away the plans when Jobs convinced him otherwise. On April 1, 1976, Apple Computer was founded; by 1978 the Apple II was a hit, and the company had acquired big-name advertising and management talent; in 1979, with the arrival of the VisiCalc spreadsheet program, it became a national sensation.

Meanwhile, the lunatic pace of growth had driven the staff to burn-out and afflicted the company with what Moritz calls "creeping professionalism": rigid hierarchies, security systems and management which one employe complained was "trying to make Apple sound and smell like IBM." Wozniak lost interest; resentments flared; bursts of expansion were followed by purges.

In 1980 Apple was worth more than Ford Motor Company but faced crises within and without. Jobs (whose share of the company approached a quarter of a billion dollars) was involved in a nasty paternity suit. Wozniak had suffered amnesia from a plane crash. By late in the year, Moritz writes, "there was a general sense that the company was sliding out of control." Dealers called Apple's practices "arrogant." The Apple III, rushed into production too early, proved a market turkey; the long-awaited Lisa never found a wide audience; IBM had entered the market; and Apple was gambling the farm on a radically new machine called the Macintosh, the outlookor which is favorable but still uncertain.

Moritz's meticulous account is agreeably replete with segments of dialogue and anecdote. Cognoscenti may complain that his incessant focus on Apple alone precludes a sense of the surrounding competition and context. And the lay reader will be disappointed that after the first part of the book -- so rich in personal detail -- Moritz chooses to emphasize sales and financial tactics at the expense of human motivation. As Apple's agonies accumulate, one keeps wondering in vain how the principals reacted.

But for the tech-biz buff, the fascination never flags. And Kingdom, especially when read in conjunction with the two above volumes, provides a valuable and cautionary insight into the industry that will shape our digital tomorrow.