Steve "Woz" Wozniak is a co-founder of Apple Computer, and the principle designer and creator of the Apple I and Apple II microcomputers.

Along with his friend Steve Jobs, Steve Wozniak founded Apple Computer in 1976 along with a third co-founder, Ronald Wayne.

Wozniak was born on August 11 1950 to Margaret Elaine and Jacob Francis “Jerry” Wozniak. His father was an engineer at Lockheed Martin.

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Steve Wozniak profile

Steve Wozniak grew up in the 1950s in Cupertino, California. The area was predominantly agricultural at the time, but would later become known as Silicon Valley. In his book iWoz, he describes being interested in electronics from a very young age. Wozniak frequently attended science fairs and recalls winning every science fair competition he entered, except one.

Wozniak has spoken as a child longing for a Data General Nova computer. When his dad told him, "they cost as much as a house" he replied "Well, I'll live in an apartment."

His hobby at high school was redesigning electronic components. He also liked to play pranks, and recalled inventing a device that could cause interference with television signals at the push of a button. He would use it to try and control people, by convincing them that the television would only work if they hit it, or held the antenna or stood on one leg and so on.

Wozniak didn’t have many companions at high school. But became friends with Steve Jobs after a mutual friend introduced them because they both liked electronics and playing pranks.

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After high school Wozniak went briefly to the University of Colorado in Boulder, but due to the high costs of attending he enrolled in his second year at De Anza College, San Francisco and later worked at Hewlett-Packard.

In 1976 Steve Jobs approached Wozniak to assist him in designing and building a video game called Breakout. Jobs had been offered $750 with a bonus for every chip fewer than 50 he could use to complete the game, by Nolan Bushnell, the founder of Atari. Bushnell was reportedly tired of Atari engineers typically using between 150-170 chips per machine.

See: Woz on Jobs and Breakout

Wozniak and Jobs worked on the design for four days without sleep, finally delivering a design to Atari that used 44 TTL (transistor-transistor logic) chips. Wozniak’s original design used 42 chips but Wozniak said “we were so tired we couldn’t cut it down”.

Jobs reportedly only shared $375 with Wozniak telling him only of the $750 payment (not the bonus). Wozniak reportedly did not learn about the bonus until 10 years later, but said that if Jobs had told him and said he needed the money, he would have given it to him.

To found Apple Wozniak sold his HP-65 calculator (then worth $500) and Jobs sold his VW Microbus. Wozniak was the product designer, Jobs led the business and sales side of things. Wozniak and Jobs built user-friendly computers from the Jobs’ family garage.

Wozniak first designed the Apple I computer, a so-called “homebrew” device. It was designed to be sold to hobbyists and sold demonstrated in July 1976 to the Homebrew Computer Club in Palo Alto, California. Unlike other home computers, which were sold as kits, the Apple I was a fully integrated circuit board. Buyers still had to add their own case, power supply, keyboard and display.

Thanks to Steve Jobs’ ability to hustle high quality components for a low costs, the original Apple I designed by Wozniak was a seriously impressive computer that sold for $666.66 (Wozniak reportedly choose the price because he liked recurring numbers, and it was a third more than the build cost). Wired’s Gary Wolf explains: “The owners of an Apple I got a machine with 8K of RAM. After they loaded Woz's 4K Basic into it - by hand, programming in hexadecimal - and added a keyboard and a monitor and wired two transformers onto the power supply, they could use the remaining 4K to run their programs. It was a computer for serious hobbyists, who loved it as they probably have never loved another computer since.”

See: Rare Apple I computer auctioned off for $387k

Wozniak then went on to engineer the Apple II computer, which was released in 10 June 1977. The Apple II computer, in particular, is notable for being the first commercially successful personal computer to feature a central processing unit, keyboard, colour graphics and a floppy drive. In both terms of design and build it is much more advanced than its predecessor, appearing similar to the type of home computer we would recognise today. By 1983 Apple had a stock value of $985 million.

In 1984 Wozniak went on to assist Apple in designing the Apple Macintosh computer, but in 1987 he stopped working principally for Apple. Wozniak has never formally left Apple though, and remains an employee receiving a stipend (estimated to be around $120,000) per year. He is an Apple shareholder, however, and has an estimated net worth of around $100 million.

Wozniak has been involved in several technology ventures post-Apple although none have had the same impact in the technology market. His first venture CL 9 was designed to build universal remote controls, and his Wheels of Zeus project was designed to use GPS technology to help locate everyday objects. He is also on the Board of Directors at Ripcord Networks, Danger. Inc and founded Acquicor Technology along with other Apple alumni Ellen Hancock and Gil Amelio.

He has also organized US music festivals called Un.U.Son (Unite Us In Song) and is a noted philanthropist. Wozniak founded the Electronic Frontier Foundation, an organisation that defends human rights in the digital age, and was the founding sponsor of the Tech Museum, Silicon Valley Ballet and Children’s Discovery Museum of San Jose. “I never wanted money” says Wozniak “So as soon as I had all this wealth from Apple I pretty much tried to get rid of it, and I invested in a lot of museums.”

See: Woz-fest bigger than Woodstock

He maintained connection with Steve Jobs until Jobs’ death in 2011, although in 2006 he told The Seattle Times that he and Jobs were not close friends.

Wozniak has never claimed to have invented the personal computer. Apple tactfully uses the phrase “Apple ignited the personal computer revolution in the 1970s with the Apple II”.

Although computers have been sold to the general public since the mid-1960s, and many individuals had built microcomputers, the home computer as we know it (CPU, storage, screen and keyboard) had never been sold in quantity before Wozniak’s Apple II.

If any single person could lay claim to being the architect of the modern home computer as we know it; it would be Steve Wozniak.