Stephen Wozniak, along with Steven Jobs, cofounded Apple Computer, Inc., and developed one of the most popular personal computers ever marketed. His contributions to Apple were almost exclusively technical--Jobs pushed the marketing potential of the Apple, while Wozniak provided the engineering know-how.

Wozniak's father, Jerry, was a Lockheed engineer, and his mother, Margaret, was president of a local Republican women's club. Young Wozniak grew up in Sunnyvale, a suburban development located in the Santa Clara Valley, now known as Silicon Valley. He was surrounded by the technological wizardry that grew out of Sputnik and the race for space. His parents provided a stable, close-knit environment.

Wozniak was an early devotee of electronics and in the fifth grade created a voltmeter from a kit. His interest in science and engineering led to a number of homemade devices: a ham radio, a makeshift electronic tic-tac-toe game, a calculator. By the...