Franking machine

Claim 1

A franking machine for franking items of mail including electronic means (11) to carry out accounting functions in relation to usage of the machine in franking operations; storage registers (28) connected to said electronic means to store account records; said electronic means being responsive to command signals to carry out functions indicated by said command signals; a secure housing (10) securely containing said electronic means (11) and said storage registers (28); a communications port (12) extending through a wall of said housing to which a peripheral device external to the franking machine may be connected to communicate with said electronic means; characterised in that the communications port (12) is a general purpose port to which any of a plurality of peripheral devices (19, 29) may be connected, in that a plurality of electrical connections (I, O, VCC, VDD) connect a plurality of contacts of the connector (12) to the electronic means (11), a group of said contacts (I, O) having signal carrying functions determined by said electronic means (11); said electronic means being operative in response to a command signal indicating a function to be carried out to determine whether the indicated function requires transmission of signals by way of the general purpose port and a specific one of said plurality of peripheral devices with which communication is to be effected and in response to determining that said indicated function requires transmission of signals by way of said general purpose port with a specified one of said plurality of peripheral devices to set the signal carrying function of the contacts (I, O) of said group to enable transmission of signals by way of the general purpose port (12) to and from said specified peripheral device (19, 29).