| 摘要 |
PURPOSE:To make it possible to remove unused memory chips from a memory board which mounts plural memory chips by using the initial address of the memory board always as the start address of a stated memory chip. CONSTITUTION:Switch mechanism 3 to generate memory chip start address, mechanism 6 to make the address complement and mechanism 4 to receive the absolute start address are provided to the addressing device of memory board, 2 which mounts memory chips A-H, the complemented address and absolute start address are added by adder 7 and the memory chip according to the output of address 7 is selected by selector 8. Thus, when memory board 2 is used under the capacity less than the full capacity, unused memory chips can be removed by converting the absolute start address into the standard address of memory board 2. |
