While at Hewlett-Packard, Wozniak used his technical genius to create a “blue box,” a pocketsize phone attachment that made long distance calls for free. Wozniak reunited with friend Steve Jobs at Hewlett-Packard to form Apple Computers. Teaming up with Jobs, Wozniak led the engineering side of the Apple I, a logic board with read-only memory and a built-in video interface. He also played a significant role in the development of the first widely used PC, the Apple II, as well as the Apple IIe and Lisa. In 1985, Wozniak left Apple to take a job combining his two passions, computers and education. Wozniak continues to instruct teachers and students on the basics of computer technology.