Abstract: An IC information card includes a programmed microprocessor and a nonvolatile read/write memory (EPROM) embedded in a plastic card. Terminal contacts on the face of the card enable interfacing with a reader/writer coupled to a host computer, such as an IBM-XT. The data storage portion of the memory in the card is segmentable into one or more data zones, each requiring either no access code or one or more access codes to be entered in the card in order to access (read and/or write) that zone. Segmentation of the card memory and the assignment of required access codes is achieved by writing a zone definition table and one or more access codes into the card memory using a special access code that is fixed in the microprocessor program. The access codes for the data zones are thus stored on the card and the programmed microprocessor in the card compares incoming codes to the stored codes to determine whether access to a particular data zone is permissible.