Abstract: A method of connecting a card to a terminal including the following steps: a) on receiving corresponding respective commands from the terminal, it modifies the contents of the card memory by provisionally recording in the card memory each of said interdependent items of information without losing prior values corresponding to said items; and then b) the modifications are finalized either by all of them being confirmed or by all of them being discarded.

Abstract: The card contains value information suitable for being debited by the machine in consideration for delivering goods or service. The machine causes a ratification flag stored in the non-volatile memory of the card to be modified between two states, namely: a ratified state corresponding to the case where the preceding transaction performed with the card, whether with the same machine or with another machine, took place correctly, and a non-ratified state for the case when said preceding transaction was interrupted in the course of being executed. The machine successively: conditionally debits the card if the flag is in the ratified state; causes the card to put the flag in the non-ratified state if a debit took place in the preceding step; then causes the goods or service to be delivered; and if delivery takes place effectively in the preceding step, causes the flag to be put by the card into the ratified state.

Abstract: A method manages collisions in a system for interchanging data between portable objects and at least one terminal suitable for co-operating with a plurality of the portable objects simultaneously. The terminal sends out call messages to the portable objects. A portable object conditionally sends a message to the terminal in response to the call with a probability that may be less than 100%, the response containing an identifier specific to the portable object. The receiver receives a response from an identified portable object and in absence of the response colliding with a response sent out by another portable object, a specific data communication link is established between the terminal and the identified portable object. The portable object modulates the probability of response over time depending on whether or not it has itself already responded previously to a call message sent out by the terminal.

Abstract: A method handles collisions in a data interchange between portable objects and at least one data transceiver. The method includes the steps of the transceiver transmitting to said plurality of portable objects general call messages, each including a collision probability modulation parameter. Each portable object conditionally transmits to the transceiver a general call response with a probability of less than 100% as a function of the collision probability modulation parameter and having a specific identifier. The transceiver receives a general call response message, and in the absence of any collision between said message and a message transmitted by another portable object, a specific data communication link is established. Otherwise the method returns to the first step and repeats, optionally modifying the dynamic range of the probability modulation parameter.

Abstract: A system for the exchange of data between a transfer device and an "intelligent insertable object" that comprises an electronic memory associated with an access circuit and emulates a magnetic recording support with respect to a magnetic read/write head of the transfer device, the data exchange bit rate of the transfer device being greater than that of the circuit providing access to the memory of the insertable object, the system comprising means to limit the bit rate of useful elements in the apparent bit rate of data elements entering and leaving the transfer device, so that it is compatible with the bit rate leaving and entering the circuit providing access to the memory of the insertable object. The system can be applied notably to the exchange of data elements between a microcomputer and an electronic card that can be inserted into the disk drive of the microcomputer or into a memory card reader.

Abstract: A time accounting system for accounting parking subject to charge periods which includes a card having an electronic memory in which each memory location can be individually and irreversibly written in order to represent a time unit credit allocated to the holder of the card. The system also includes a portable case in which the card can be inserted and which has an internal clock circuit and a coupling circuit, as well as a writing circuit. The case is designed with means for temporary storage of a time unit credit which is activable if the time credit remaining in the inserted card is less than the parking time of the holder.