| 摘要 |
PURPOSE:To improve the efficiency of a memory device usage and to prevent an access competition by storing subscriber data with filling from the head of a block without leaving a space and managing the vacancy in every block by displaying the number of the data on a counter. CONSTITUTION:When new subscriber data is added to a block 57, it is set from the head of a vacant area and '1' is added to a counter 52. Supposing that a subscriber data 2 is deleted from the block 57, the place becomes the vacant area, a subscriber 4 is relocated to the place to use efficiently a storage device 2 and the value of the counter 52 becomes '3' by subtracting '1'. At such a time, the pointer 43 on a subscriber data index table 41 to index the subscriber data 4 is replaced from a position 63 to a position 61 to be indexed accurately. Thus, since the vacant area in one block is managed, an overhead for vacant area management of the storing capacity of the memory device is exceedingly small. |
