Steve Jobs was not accustomed to boos, but there he was, on stage at the airy and decrepit Park Plaza Castle auditorium in Boston, absorbing a crescendo of unhappiness. It was 1997, the year Jobs replaced Gil Amelio and declared himself “interim CEO” of Apple (AAPL), saying he was too busy with Pixar and family to take over permanently. At the annual Macworld Expo that August, Jobs told the long-suffering Apple faithful that there was still hope for the computer company but that it would first have to put aside its all-too-consuming fixation with its dominant rival, Microsoft (MSFT).

“We are shepherding some of the great assets in the computer industry. If we want to move forward and see Apple healthy and prospering again, we have to let go of a few things,” said Jobs, dressed in his trademark outfit of that era, a sweater vest and pleated slacks. Microsoft, he announced, was investing $150 million in Apple and making a promise to develop Microsoft Office software for the Macintosh for the next five years. Bill Gates popped up on a 100-foot screen, appearing pedantic and flaccid in contrast to Jobs’s swagger. “The era of setting this up as a competition between Apple and Microsoft is over as far as I’m concerned,” Jobs said after Gates’s brief and awkward speech, trying to quell the disappointed audience, some of whom appeared to be in tears.

The détente forged on that August day was, in retrospect, a cold calculation by Jobs that Apple did not need to win the old battle for the PC in order to prevail in a dawning war for digital media devices and the Internet. It was also the first bit of evidence that despite his professed ambivalence, Jobs was fully committing himself to an Apple turnaround. Colin Crawford, who ran Macworld in the 1990s along with publications such as MacWEEK, recalls asking Jobs back then why he wanted to return to the company he had founded. “He sort of looked at me quizzically and said that his and Apple’s DNA were...