Method of supervising storage of data in a memory card having EEPROM and a memory card system using the same

摘要

A method of supervising the storage of picture data, character data or similar data in a memory card having an EEPROM (Electrically Erasable Programmable Read Only Memory) and a memory card system using the same. When the EEPROM in an initialized state, a controller formats it into a data area made up of a plurality of data subareas and a directory area made up of a plurality of supervisory subareas each being associated with respective one of the data subareas. In the event of writing data in any one of the data subareas, the controller writes a serial number or similar occupancy code at the leading field of one supervisory subarea corresponding to the data subarea of interest. The leading field of each supervisory subarea remains in the initialized state until the occupancy code has been written thereto.