Metering system with automatic resettable time lockout

Claim 1

An improved metering system having: a microcomputer in bus communication with a program memory and secure non-volatile memory units an integrated circuit means having an address decoder module, interrupt controller module, printer controller module, said interrupt controller module and printer controller module being responsive to control signals from said address decoder wherein said improvement comprises: said interrupt controller having a priority interrupt signal output signal which when activated causes microprocessor to execute a meter disabling routine to prevent printing of postage, a count down timer in communication with said interrupt controller having reset means for resetting said count down timer prior to said count down timer timing out and having means for causing said interrupt controller to output said priority interrupt signal when said count down timer has timed out, said resetting means further for controlling access to said secure memories, input means for receiving a combination, and means for comparing said combination with a corresponding combination stored in said secure memories, and wherein if said combination and said corresponding combination are found valid by said comparing means, then said reset means first resets said count down timer and subsequently enables access to said secure memories.