A portable, hand-held microprocessor-based terminal forms the heart of an expandable data communication system having an architecture configured so that a variety of peripheral devices can communicate directly with the microprocessor in the portable terminal. Access to the microprocessor and associated...http://www.google.fr/patents/US4530069?utm_source=gb-gplus-shareBrevet US4530069 - Expandable data communication system utilizing hand-held terminal
Expandable data communication system utilizing hand-held terminal
