TRON (1982) on Netflix

Kevin Flynn is a former employee of the software corporation ENCOM, now running an arcade. Flynn has been trying to hack into ENCOM's mainframe computer to find evidence that ENCOM's senior executive Ed Dillinger stole five video games he created. But Dillinger's supercomputer Master Control Program foils Flynn's efforts and dictates and controls most of the computer systems. One night, Flynn's former girlfriend Lora Baines and her boyfriend, ace computer programmer Alan Bradley helps Flynn break into ENCOM to shut down the MCP with Alan's security program Tron. But MCP uses Lora's matter transmission program and converts Flynn into data and sends him into the computer. Flynn finds himself in a electronic world ruled by the MCP and his evil chief henchman Sark, where computer programs are the alter-egos of their creators and are forced to compete in gladiatorial games. With help from Tron, a heroic and fearless security program and his lover, Yori, Flynn sets out destroy the MCP and help Tron liberate the system from the MCP's control, by destroying the MCP is Flynn's only way of returning to the real world.