IC card system - Patent Review 4742215

Claims

We claim:

1. An IC information card comprising:

input/output means in the card for receiving at least data, commands and keycodes and for providing at least data;

nonvolatile read/write memory means within the card, the memory means having a multiplicity of addressable bit storage locations;

first means within the card responsive to a first command, zone definition data and an entered keycode received by the input/output means for comparing the entered keycode with a first keycode stored in the card and for writing the zone definition data in a first region of the memory means only if the received keycode matches the first keycode, the zone definition data comprising one or more zone definition words each corresponding to a respective data zone in a second region of the memory means, each zone definition word specifying at least the starting address of the corresponding data zone and the size of the corresponding data zone.

2. An IC information card according to claim 1, wherein the card further comprises second means within the card responsive to a second command, keycode data comprising one or more additional keycodes and an entered keycode received by the input/output means for comparing the entered keycode with the first keycode and for writing the keycode data in a third region of the memory means only if the entered keycode matches the first keycode, and wherein each zone definition word further specifies either no keycode or one or more of the first keycode and the additional keycode or keycodes as being required to be received by the input/output means in order to read data from the corresponding zone and either no keycode or one or more of the first keycode and the additional keycode or keycodes as being required to be received by the input/output means in order to write data in the corresponding data zone.

3. An IC information card according to claim 2, wherein the card further comprises third means within the card responsive to the input/output means receiving a read command, a code specifying a particular one of the data zones from which data is to be read and any entered keycode or keycodes, for comparing any entered keycode or keycodes with any keycode or keycodes specified as being required to read data in the particular data zone and for providing data from the particular zone to the input/output means if the entered keycode or keycodes match the keycode or keycodes specified as being required to read data from the particular data zone or if no keycode is specified as being required to read data from the particular data zone, and wherein the card further comprises fourth means within the card responsive to the input/output means receiving a write command, a code specifying a selected one of the data zones in which data is to be written, data to be written in the selected zone and any entered keycode or keycodes, for comparing any entered keycode or keycodes with any keycode or keycodes specified as being required to write data in the selected data zone and for writing the received data in the selected data zone if the entered keycode or keycodes match the keycode or keycodes specified as being required to write data in the selected data zone or if no keycode is specified as being required to write data in the selected data zone.

4. An IC information card according to claim 3, wherein data is stored in each data zone as successively located data records and each zone definition word further specifies the maximum number of data records that can be stored in the corresponding zone, the length of the data in each data record in the corresponding zone and a zone allocation area in the memory means for storing data indicative of the location of the next data record to be stored in the corresponding zone.

5. An IC information card according to claim 4, wherein the zone allocation area is located in the corresponding zone and contains one or more successively ordered bit positions each associated with a respective data record position in the zone, each bit position of the zone allocation area containing a first or a second binary state depending upon whether or not the data record position associated with that bit position contains a data record, respectively, and wherein the fourth means is further responsive to the contents of the zone allocation area of the selected zone for writing a data record in the selected zone in the data record position therein that is associated with the lowest order bit position of the zone allocation area the