Steve Jobs's IQ

At Homestead High he joined an electronics club and, through a friend, met Steve Wozniak, five years older and already a gifted engineer. The two bonded over pranks, Bob Dylan and circuits.

Their first joint venture was a "blue box" that mimicked telephone-network tones to make free long-distance calls. Jobs later said that without it there would have been no Apple: it showed them two kids could build something that controlled a vast system.

He also called Hewlett-Packard co-founder Bill Hewlett at home, aged about 12, to ask for spare parts, and came away with a summer job.

He enrolled at Reed College in Portland, left after one semester because the fees were eating his parents' savings, and stayed on for a year and a half sleeping on friends' floors and auditing classes that interested him, calligraphy among them.

Back in California he took a job at Atari, saved money, and travelled to India in search of spiritual teachers. He returned with a lifelong interest in Zen Buddhism and an intuition-first way of making decisions that shaped his design sensibility.

Jobs and Wozniak founded Apple in 1976 to sell the Apple I, a bare circuit board Wozniak had designed. With investor Mike Markkula they launched the Apple II in 1977, one of the first mass-market personal computers, and Apple went public in 1980.

He championed the Macintosh, launched in 1984 with a graphical interface inspired by a visit to Xerox PARC. Sales disappointed; a power struggle with John Sculley, the CEO he had recruited from Pepsi, ended with the board stripping him of his role in 1985. He resigned.

He founded NeXT to build high-end workstations for universities. The hardware sold poorly, but its NeXTSTEP software was advanced, Tim Berners-Lee wrote the first web browser on a NeXT machine.

In 1986 he bought Lucasfilm's computer-graphics division for about $10 million and funded it for years. It became Pixar. Toy Story (1995), the first fully computer-animated feature, was a hit, and Pixar's IPO that year made him a billionaire.

Apple, near bankruptcy, bought NeXT in 1996 and Jobs was running the company within months. He cut the product line to four machines, struck a deal with Microsoft, and launched the "Think Different" campaign.

Then came the run: the iMac (1998), iPod (2001), iTunes Store (2003), iPhone (2007), App Store (2008) and iPad (2010). NeXT's software became the foundation of macOS and iOS.

Diagnosed with a rare pancreatic neuroendocrine tumour in 2003, he delayed surgery for months to try alternative treatments, a choice he later regretted, according to Isaacson. He had surgery in 2004 and a liver transplant in 2009.

He resigned as CEO in August 2011 and died on October 5, aged 56. His 2005 Stanford commencement speech, built around dropping out, being fired and facing death, remains one of the most-watched speeches online.