Abstract: An erasable circuit provides a nonvolatile memory for holding key codes in at least two memory locations. At least one of these locations is a master key code address. "Master key" here means a key that can command a lock to store a key code or to erase a stored key code. An input device makes electrical connection to an electronic key--such as a ROM key--to receive from the key an electronic code that is in essence unique to that key. The lock also has provision for comparing such a received code with the contents of each of the address locations, and it responds to the comparison by performing a lock-management function. Such functions include opening or closing a lock, changing the state of a key switch, rejecting a key, and validating or invalidating a key--particularly including a master key--by physically changing the contents of the nonvolatile memory. Perceptible signals identify the lock-management function for human users.

Abstract: A compact hand-holdable implement or key for controlling an electronic lock mechanism is disclosed. The implement is sized and configured for easy, convenient and comfortable gripping, aligning with a mating receptacle of the lock mechanism, and bringing into and out of desired engagement with the receptacle. The illustrated implement includes a memory chip. It has an elongated handle with a front-to-rear axis and electrical implement contacts at its front end connected to the memory chip. The user grips the handle with the user's thumb and at least one finger generally aligned with the handle axis for clear visibility of the front end and the receptacle. This also allows for easy and comfortable combined movement which both aligns the implement with the receptacle and moves it forwardly into the receptacle.

Abstract: A compact hand-holdable implement or key for controlling an electronic lock mechanism is disclosed. The implement is sized and configured for easy, convenient and comfortable gripping, aligning with a mating receptacle of the lock mechanism, and bringing into and out of desired engagement with the receptacle. The illustrated implement includes a memory chip. It has an elongated handle with a front-to-rear axis and electrical implement contacts at its front end connected to the memory chip. The user grips the handle with the user's thumb and at least one finger generally aligned with the handle axis for clear visibility of the front end and the receptacle. This also allows for easy and comfortable combined movement which both aligns the implement with the receptacle and moves it forwardly into the receptacle.