A card and terminal system.

摘要

An IC card system comprises an IC card terminal (l) and an IC card which is inserted into the terminal (l), the terminal (l) including a power-supply circuit (35) for supplying data-writing power to a memory pro­vided in the IC card, and a timer circuit (36) for mea­suring a period of time corresponding to the maximum time during which one unit of data can be written into the memory. The supply of power to the IC card is re­newed every time the IC card sends a request for an unit of data, within the period of time set in the time-­measuring circuit (36). The supply of power is stopped when the IC card makes no request for an unit of data within the above-mentioned period of time.