They were one of the most celebrated pairs in business. Steven Jobs brought the creative genius, John Sculley the marketing prowess, to a corporate marriage that raised Apple Computer Inc. from a California curiosity to an American legend.

This week, that seemingly inseparable duo marks the five-year anniversary of their bitter separation, a split that sent Jobs off to start anew and Sculley struggling to revitalize a shaken company.

But as both men are finding, going it alone is no easier than building a partnership.

In a curious coincidence of timing, each is again facing a crucial crossroads. Jobs,having failed to wow buyers with a sleek black computer his Next Inc. introduced two years ago, is preparing to revamp his product line in what is likely to be the firm's last shot at commercial success.

Sculley, with new products due out next month, hopes to turn around Apple's flagging fortunes and lend clear direction to a company that appears to be fumbling in the face of sharpening competition.

The two men's problems may spring from the same source. Both have staked their corporate fortunes on promoting a high-brow image, betting that the distinctiveness of their products would fetch them premium prices. No Chevrolets -- theirs were the BMWs of the computer world.

The strategy brought each certain indisputable successes. But lately, each has also suffered the consequences after being humbled by cost-conscious customers.

Firms and people who dare to be distinctive frequently are caught in this bind. "In order to do anything interesting on this planet, you've got to be insanely arrogant," said Tom Peters, the management consultant and co-author of "In Search of Excellence." "One millionth of 1 percent are enormously successful because their arrogance happened to meet the needs of the times. Then they stay arrogant and the times change."

The test of whether the two most-talked-about personal-computer moguls can change with the times comes first for Jobs. At a gala affair next Tuesday, he will return to San Francisco's symphony hall where two years ago he rolled out an all-black computer as notable for its elegant appearance as its breakthrough technology. Technically, it was a masterpiece, sporting such flashy features as voice recording and playback, easy-to-use software and an optical disk that could store so much information that, Jobs boasted, "we can take our entire world in our backpack."

But customers balked. Many liked the distinctiveness of the "black cube" but fewer than an estimated 10,000 have been willing to pay the $6,500 to $10,000 to buy one.

"There are lots of properties of the Next that are attractive to us," said Bill Kelly, whose lab at Boys Town National Research Hospital in Omaha has ordered two machines. Kelly, who thought he'd be a buying a lot more Nexts, found the computer trickier to use than he had expected. "If I had to do it all over," he said, "I might spend the money on faster PCs."

Next is likely to answer certain customer concerns. According to unofficial reports, it will unveil a less expensive machine as well as a souped-up model that offers color, a sorely needed feature. The company also is expected to drop the built-in optical drive, criticized as slow and impractical, for more standard industry disk drives. Importantly, the firm also is likely to announce some new sales and the availability of software packages.

In a recent interview, Jobs, 35, acknowledged disappointment. "I'm extraordinarily happy with what we have accomplished technology-wise but we have not yet made it commercially," he said. "Things take time and I am an impatient person."

He also is a perfectionist. At Jobs's insistence, for example, Next returned an expensive piece of machinery destined for its factory because it failed to conform to Next's white-black-gray color scheme. The machinery had been finished in gray, but not with the paint Next had provided.

Though friends say he is as driven as ever by details, Jobs likes to think he has stepped away from fussing with every decision at his 450-person company. Certainly he spends less time at the office than during the 90-hour weeks he put in developing the Macintosh at Apple. These days he's likely to be found on weekends with his girlfriend in yuppie cafes, his black Porsche parked out front.

The brash multimillionaire can at least still talk like a child of the '60s. Touting the easy-to-use features of the Next computer, Jobs glibly describes it as simple enough for the "mere mortal" to use.

His choice of words is ironic.

They are the same ones used by Sculley in a 1989 Fortune magazine article that rankled company managers. Describing the benefits of a weeks-long sabbatical -- a break afforded all Apple employees after five years -- Sculley said he was reminded then that "I'm a mere mortal."

Sculley's fans note that he actually has accomplished far more than your average human. Since Jobs left, Apple has mushroomed from $2 billion to more than $5 billion in sales, and from 6,000 to 12,000 employees. Sculley has reshaped the Macintosh into more of a mainstream computer and made inroads into the corporate market. The company has $1 billion in cash and virtually no debt.

Nevertheless, problems abound. Largely because it focused on selling high-priced computers, Apple has seen its U.S. market share slip sharply -- from 16 percent in 1985 to 11 percent last year, according to market researcher Dataquest Inc. And its over-priced "no compromises" portable Macintosh was a flop. "With {Apple's} priorities focused on higher-end systems ... that has caused a lot of the troubles today," said John Zeisler, vice president of marketing at Claris, an Apple software subsidiary.

Internally, politics took hold. Nearly constant reorganizations among key sales and marketing officials have kept confused dealers and customers guessing about the company's priorities. Swayed by the newest managers in place, Sculley has reversed a number of key strategies, including earlier decisions to allow Claris to become independent and to part ways with software company Adobe Systems Inc. And a survey of employees conducted earlier this year reportedly found that while they remain unusually upbeat about Apple's philosophical mission, more than half said the firm lacked a clear business direction.

Insiders say things are looking up now. The October unveiling is said to include several competitively priced computers, including one model under $1,500 and another featuring Apple II-compatibility -- a bid to regain lost momentum in sales to schools. The firm, recognizing the downside of pursuing its unique design, also is formulating technologies to better coexist with International Business Machine Corp.'s PCs.

Sculley, who was unavailable for an interview, remains the shy chief executive whose reserved nature -- and $2.2 million 1989 compensation package -- contributes to his air of aloofness, something that he apparently has been trying to shed. Digging in, he recently took on the tough day-to-day task of managing the company's new products, a role that has raised eyebrows given his lack of engineering experience.

Further, he hauled executives into his office not long ago and declared an end to politicking, vowing himself to hold a more steady course. "He has such a quick mind that when he sees something new his instinct is to change it, and he didn't see before what that did to everybody else," said Larry Tesler, who heads an advanced engineering project reporting to Sculley. "Now he sees that."

Sculley may be able to reform his own shortcomings, but it's unlikely he will be able to restore warm relations with his former protege. Jobs and Sculley reportedly talk only rarely, and few people stop to ponder these days what could have been.