Abstract: A method for inhibiting tampering with data on a magnetic stripe card is disclosed. The data are erased if the card is prematurely withdrawn from the reader/writer. A write protect bit is set and recorded on the card if the power source is interrupted. Apparatus for activating the tamper-proofing techniques are disclosed.

Abstract: Method and apparatus for registering selected new magnetic data on magnetic stripe cards for use in a vending machine account control system, such as is employed with a photocopy machine. Specifically, card author is provided which consists of a keyboard with data entry and operation control keys, keyboard scanning means, an input/output storage port and a bus connector which can be coupled directly to a duplicator controller. Upon connection of the card author to the duplicator controller, and with the duplicator controller in a card author mode, the duplicator controller initiates interactive operation with the card author in order to request certain information not normally accessible to manual manipulation as by a key operator. Through its display, the duplicator controller requests entry of at least three different types of values, a value representing worth of a card to be authored, an account number, and a delimiter value.