A cartridge-controlled system whose use is limited to authorized cartridges. Blocks of instructions of a program designed to run on the machine are encrypted by the machine manufacturer using the private key of a public-key cryptosystem pair. The machine, during an initialization step following the insertion...http://www.google.com/patents/US4670857?utm_source=gb-gplus-sharePatent US4670857 - Cartridge-controlled system whose use is limited to authorized cartridges
