| 摘要 |
PURPOSE:To enable a user to recognize the time limit of storage of data on a memory card by providing the input/output device with a timer function and writing use state data in the memory area on the memory card from the input/output device. CONSTITUTION:A timer 6 sends the current time to a CPU 4 as data at all times and the data on the current time is further written in the memory area 1a of the memory card 1 through the CPU 4 at constant intervals of time. Therefore, when the memory card 1 is extracted from the card connecting connector 3b of a main body device, the time right before the card is extracted and the replacement date of a battery are stored in the memory area 1a on the memory card 1. Then when the memory card 1 is used by the main body device, the current time is compared with the old time in the memory area and the result is stored in the memory area 1a as the operation time of a backup battery 2. Consequently, it is judged whether or not the operation time exceeds the life time of the battery. |
