SYSTEM ENVIRONMENT SETTING SYSTEM

PURPOSE:To confirm the effectivity of a system resource when a power source is turned on by providing a ROM and a RAM, which are mapped to the same address space, and executing judgement according to a system environment diagnosis program stored in the ROM. CONSTITUTION:A ROM 3 is mapped as the same address to one part of the address space of a RAM 4 and when the power source is turned on, the ROM 3 is selected by a memory selection control circuit 2. In a ROM 3, a program is stored to read the environment judgement program of the system and a main program, which is stored in an external storage device 10, into a system memory and when the power source is turned on, the environment judgement program of the system is executed. According to the environment judgement program of the system, the presence and absence of a board mounted on the system and the resource connected to the system is judged. Thus, even when the configuration of the system is changed before the power source is turned on, the current configuration of the system can be grasped before the main program is operated.