Steve Jobs was obsessive about the pursuit of perfection. When he bought a family home after his son was born, he didn't just pop to Ikea for a coffee table and some chairs. Oh no. "We spoke about furniture in theory for eight years," his wife, Laurene, says. "We spent a lot of time asking ourselves, 'What is the purpose of a sofa?'" (I know this one: it's to sit on.)

Walter Isaacson's biography of the Apple svengali is peppered throughout with such eyebrow-raising anecdotes. For several years up to his death in October, Jobs gave the writer his full co-operation, and did not (for once) attempt to exercise any control over how he was portrayed. The result sometimes feels less "warts-and-all" and more "all-warts".

The computer pioneer could be, in his own words, an "asshole". Colleagues said he projected a "reality distortion field", which convinced employees, rivals and the press that the impossible was possible. It sprang from a belief that the rules of normal behaviour did not apply to him. In the early days of Apple, he claimed his vegan diet meant he didn't need to shower, and he relaxed by soaking his feet in the loo ("a practice that was not as soothing for his colleagues", Isaacson writes drily). Pulled over for speeding in 1984, he waited for a few moments as the policeman wrote his ticket, then honked his horn impatiently. He was, he explained to the traffic cop, in a hurry.

Jobs may have cried frequently when crossed, but he could be frighteningly cold to those he believed had betrayed him. Often he would scream at employees and tell them their work was "totally shitty", even if he later embraced it - and took the credit. Jonathan Ive, the trusted English-born lieutenant whose close collaboration with Jobs led to the sinuous designs of the iPod and iPhone, is one of several friends who complain about this.

Yet perhaps the most shocking example of his callousness is one that Isaacson describes with little fanfare. After abandoning a pregnant girlfriend at 23 - Jobs's reality distortion field became a mirror and he convinced himself that he was not the father of her baby - he met a young graduate called Laurene Powell and proposed to her twice before she became pregnant. Then, abruptly, he broke up with her and crowdsourced a decision on their future, asking dozens of his friends if she was prettier than his ex. "It was probably fewer than a hundred,"saacson writes. (The two then married and lived happily for 20 years until his death.)

The triumph of this biography, however, is that Jobs's mountain of peccadilloes is weighted perfectly against his undeniable triumphs. Isaacson makes a convincing case that he was an artistic visionary with pure motives, driven only by a love of "the product". Jobs knew how to inflame desire for something you didn't even know you wanted: a computer with a graphical rather than text interface, a phone with no keyboard, a computer the size and thickness of a magazine.

He also ruthlessly exploited other companies' shortfalls. Take the graphical user interface - essentially, the use of a picture-based desktop rather than lines of text - that put the early Apple computers so far ahead of the competition. The interface was originally developed by a rival firm called Xerox Parc, but the management there did not understand its potential significance. Jobs did, and promptly appropriated it. (When Bill Gates used the same tool to design Windows, Jobs accused him of "ripping us off". Gates's reply is immensely endearing: "Well, Steve . . . I think it's more like we both had this rich neighbour called Xerox and I broke into his house to steal his TV set and found out that you had already stolen it.")

The comparison to Gates, his near-exact contemporary, is illuminating. The Microsoft man is cool, methodical and humane: Jobs was fiery, intuitive and unreasonably demanding. Their approaches to design were equally opposed, Gates believing in licensing Windows to any hardware manufacturer who would pay, while Jobs wanted "end-to-end control" of the user's experience.

Throughout the 1980s and 1990s, it seemed that Gates's promiscuous approach guaranteed him market dominance, until Jobs made a triumphant return to Apple in 1997, 11 years after being ousted in a boardroom coup, and led the company to greatness with a raft of iDevices. Apple surpassed Microsoft's valuation in May 2010, and last quarter it had larger cash reserves than the US Treasury.

The only duff moment here, aside from too much boardroom infighting for my taste, is when Jobs woos Bono to release U2's records on iTunes. The author retells the story breathlessly, but it is clear that behind the billing and cooing about artistic integrity, two monumental egos were jockeying shamelessly for supremacy.

Isaacson ends the book with Jobs slowly succumbing to the cancer that killed him last month. The unspoken question is whether Apple can thrive without its founder. This biography's great achievement is to interweave the personal and the professional, showing how Jobs the monster and Jobs the genius were indivisible. Apple may survive, but it will miss its monstrous genius.

Steve Jobs
Walter Isaacson
Little, Brown, 627pp, £25