The 1982 sci-fi film set in a computer is 'Tron'. It was written and directed by Steven Lisberger, and stars Jeff Bridges, Bruce Boxleitner, David Warner, Cindy Morgan, and Barnard Hughes. The movie follows a computer programmer who is transported inside the computer world of a powerful mainframe computer. The film was a box office success and was nominated for two Academy Awards. It has since become a cult classic and spawned a franchise, including a sequel in 2010.