An electronic postal meter is provided with a date setter having an access door coupled to a switch. The position of the switch is signalled to the internal computer, in order to effect a warning indication if the access or dater door is open. The computer further inhibits operation of the postal meter...http://www.google.com/patents/US4347506?utm_source=gb-gplus-sharePatent US4347506 - Electronic postage meter having check date warning with control for overriding the check date warning
