Abstract: A credit card includes a memory having first and second zones in which are respectively stored variable and fixed data. The data stored in the first zone includes first, second and third bit fields respectively representing a card serial number, a card invalidation character and a card validation character. The first, second and third bit fields are subject to change by improper use of the card. The first, second and third bit fields are read to derive first, second and third signals. The second signal is compared with a predetermined signal indicative of a desired value for the second field. A set of bits is written into the third field in response to the second signal being equal to the predetermined signal and the first signal being equal to a stored signal indicative of an assigned serial number. The set of bits written into the third field is tested to determine if the bits were properly written into the third field.

Abstract: A microprocessor architecture which permits automatic programming of a non-volatile memory included on the same chip as a processing and control unit. The microprocessor includes a permanent memory such as an EPROM which can be electrically written word by word. The microprocessor additionally includes a processing and control unit connected to the permanent memory through two sets of data and address registers. Circuits are also included for distributing memory write voltage in a manner which does not interfere with normal operation of the microprocessor. As a result, the data contents at one memory location can be modified (written) the same time instructions are being read from another memory location. Memory writing can alternatively be effected by a sub-program comprising a sequence of microinstructions, or by a write automaton comprising hard-wired logic circuits.

Abstract: A portable data or information carrier in the form of a card or the like. In order to maximize the confidentiality of information stored in the carrier, and more specifically to limit the amount of information available to a would-be defrauder monitoring data lines connecting the data carrier to external devices, the data carrier includes a microprocessor and an operatively associated protected memory to which access is protected. The memory includes at least one key or code which is compared to a key received from a device external to the data carrier to determine whether a particular operation is authorized. To ensure that the data carrier consumes the same amount of current whether the requested operation is authorized or unauthorized, the data carrier includes "access" and key "error" memory elements of the Electrically Alterable Read Only Memory (EAROM) type, and a bit is stored in the respective memory element in either event.

Abstract: According to the present invention, a flat package for at least one integed circuit device having output pads comprises a supporting member for the IC device, a plurality of output terminals external to the package, an array of conductors connecting the said output terminals to the said output pads of the device, and a protective means. The supporting member is a wafer and the output terminals of the package are contact islands arranged on the said wafer. At least those conductors belonging to the array which are attached to the said contact islands rest on the said supporting wafer, and the protective means comprises an electrically insulating encapsulation which partly covers the supporting wafer and which leaves exposed at least the contact islands.

Abstract: A portable data or information carrier in the form of a card or the like. In order to maximize the confidentiality of information stored in the carrier, and more specifically to limit the amount of information available to a would-be defrauder monitoring data lines connecting the data carrier to external devices, the data carrier includes a microprocessor and a memory operatively associated with the microprocessor. The memory has three particular zones, namely: (1) a secret zone in which reading and writing operations only by internal circuits of the data carrier are permitted; (2) a working zone in which any reading or writing operations are permitted; and (3) a read zone where only reading operations are permitted. The secret zone of the memory includes at least one key or code which is compared to a key received from a device external to the data carrier to determine whether a particular operation is authorized.