Steve Wozniak, co-founder of Apple, has told delegates at the Intel Developer Forum in San Francisco of the joys of engineering and his theory of what makes for a happy life.

The essence of good engineering is to be excellent at maths and have total attention to detail, according to Wozniak.

He also said that successful computer design should always be performed in small teams with a clear leader showing the way.

"The best ideas come within small groups. That means you can be better than large corporations with huge numbers of employees," he said.

"I was lucky. I did not have a bunch of inputs vying for their thing to go into the Apple."

Wozniak said that his father had been pivotal in his development by teaching him electronics from the ground up, starting with atoms and electrons.

By 10 he was designing electronic tic-tac-toe games, and at the age of 16 he started designing computers inspired by a handbook for the PDP 1 microcomputer.

"I had time on my hands, no hope of a girlfriend and it was so intense, the sort of thinking to make code work on 4-bit processors," he said.

"Even when I was designing the first Apple at the Homebrew Computer Club I never raised my hand and never spoke. Shyness helps when it comes with a streak of rebellion; it means you don't have to go along with everyone."

Wozniak explained that he and his friends would drive up to Stanford at the weekends and break in to read computer manuals and magazines.

No breaking and entering was required, he said, because Stanford was "full of smart people and smart people are always forgetting to lock doors".

He praised Apple co-founder Steve Jobs, saying that he had been pivotal to Apple's initial and current success.

Wozniak described Jobs as disloyal for leaving the company in 1985, but is glad that he is back and making world-changing devices.

"A lot of times you become what you want to be and I wanted to be an engineer," he said.

"Steve had dreams of being a great person, like Shakespeare and Einstein, who are well known throughout the centuries.

"Every time I would make a computer he would want to sell it, and the fourth one was the Apple II."