Norton was born in Aberdeen, Washington and raised in Seattle. He attended Reed College in Portland, Oregon, graduating in 1965. Before he became involved with microcomputers, he spent a dozen years working on mainframes and minicomputers for companies including Boeing and Jet Propulsion Laboratory. His earliest low-level system utilities were designed to allow mainframe programmers access to a block of RAM that IBM normally reserved for diagnostics. This foreshadowed his personal computer work, where he became known as a knowledgeable author of low-level system utilities and reference books.