items are franked or each time the machine is powered up application_number US 57532395 A description referring first to fig1 operation of the franking machine 10 is effected by means of a micro processor 11 operating under program routines stored in a read only memory rom 12 as is well known in electronic franking machines a keyboard 13 is provided for input of data by a user and a display 14 is provided to enable display of information to the user a random access memory ram 15 is provided for use as a working store for storage of temporary data during operation of the franking machine non volatile duplicated memories 16 17 are provided for the storage of data which is required to be retained even when the franking machine is not powered accounting data relating to use of the franking machine for printing franking representing postage charges for mail items and any other critical data to be retained is stored in the non volatile memories 16 17 a motor controller 18 is controlled by the microprocessor to control operation of motors for driving means not shown for feeding mail items past a thermal print head 19 and for winding a thermal transfer ink ribbon onto a take up spool sensors 20 are provided to sense and monitor feeding of the mail item and of the ink ribbon the sensors provide signals to the microprocessor.