Software copy protection schemes for early computers such as the Apple II and Commodore 64 computers were extremely varied and creative because most of the floppy disk reading and writing was controlled by software, not by hardware.
During the 1980s and 1990s, computer games sold on audio cassette and floppy disks were sometimes protected with a user-interactive method that demanded the user to have the original package or a part of it, usually the manual.