Randy wrote: The Vectrex home game console, developed my GCE and later sold by Milton Bradley, would not run a cartridge that didn't contain at a fixed offset near the beginning the string [copyright symbol]GCE 19xx. It became standard practice to fill in the xx with 00, to produce an obviously invalid copyright message that would nevertheless convince the Vectrex to run the code. In a legal battle (possibly Sega v. Accolade?), a court ruled that if the manufacturer built into a product a mechanism that looked for a specific data pattern to enable functionality, that the data pattern could not benefit from copyright because it is purely functional rather than being any form of protected expression. Eric