The 1st input circuit which inputs the power source ON signal of the compound type computer system null 1st type which possesses the unattended operation control unit, and this unattended operation control unit

摘要

PROBLEM TO BE SOLVED: To automatically take over a job from A computer system to B computer system when any fault occurs in the A computer system, to repair the A computer system without stopping the B computer system and further to control the power source of a shared device under the control of an automatic operation controller as well. SOLUTION: The A computer system and the B computer system are respectively provided with automatic operation controllers and the shared device is provided with a multiport controller. In power-on processing, a power-on instruction signal from either one of A computer system 21 and B computer system 23 is ORed and in power-off processing, power-off instruction signals from both the A computer system 21 and B computer system 23 are ANDed.