COPY PROTECTION

摘要

A method of copy protection applicable to all items of recordable material, but as applied to CDs or mini-dics comprises providing a CD or mini-disc player with a write facility and a memory programmable with a code unique to that player, providing CDs with a once-write only writable band, writing the unique code to a CD on first use of the CD, whereby only after the CD carries the unique code can the CD be played on the player from which the unique code has been written.