An IC card system comprises an IC card, each card including a microprocessor, a communication interface, a power supply interface, and memories such as RAM, ROM and EEPROM, and an external device such as a terminal. The terminal functions to supply electric power and send commands to the IC card, and...http://www.google.com.au/patents/US4877945?utm_source=gb-gplus-sharePatent US4877945 - IC card having a function to exclude erroneous recording
