| 摘要 |
<p>PURPOSE:To simplify a equipment and to obtain the equipment operated at high speed by operating a random access memory after shifting a program stored in a read-only memory. CONSTITUTION:In the ROM 2, an input/output control program operated by a boot-strap program and an interchangeable mode is stored, however, it is allocated to only memory spaces (FFOOOO-FFFFFF) extended by a host proces sor, and the RAM 3 is allocated to memory spaces interchangeable between subordinate processors in which the input/output control program is operated. The boot-strap program which initializes a system writes the input/output pro gram stored in the ROM 2 on the addresses (OFOOOO-OFFFFF) of the RAM 3. In such a way, it is possible to simplify a decoder circuit, and to obtain a fast execution speed even when the read-only memory with low speed is used.</p> |
