| 摘要 |
PURPOSE:To extend the applied range of system extension, by bank switching with the corresponding address region through the selection of effective and ineffective extension memory, in a computer system of bank switching system. CONSTITUTION:In a computer system using a bank switching system, an extension series memory of one card is split into a plurality of series 28-31, and a coincidence signal 15 being an output signal of a comparison circuit 14 and a selection signal to switch the signal 15 into effective/ineffective signal, are added to AND circuits 22 and 23, and the effectiveness/ineffectiveness of extended series memories 30 and 31 is controlled with a data written in advance in a flip- flop 24 by the CPU. Thus, the address region corresponding to a part or all the extension memory card, other extension memory card or the same address region of the memory in the main body are achieved alternately for bank switching. |
