The machine comprises a 16-key keyboard (1), an alpha-numeric display (2), a calendar clock (3), a microprocessor (4), a program memory (5), a text memory (6), and a working memory (7), interconnected by a bus (B). A first set of messages enables normal franking operations to be performed, and a second...http://www.google.de/patents/US4928249?utm_source=gb-gplus-sharePatent US4928249 - Operating system for an electronic franking machine
