PURPOSE: To execute loading without passing through a main storage device and to drastically shorten a processing time by autonomously generating loading addresses in respective processors and transferring data to the control storages of the processors.

CONSTITUTION: The addresses of the control storages CS21 of respective processors 2 are included in the address space of a memory of a service processor SVP with respect to the main storage device M or control information for starting micro program loading mechanism which respective processors 2 have are set in one specified word. A direct memory access control DMAC 13 mechanism transfers micro programs from a hard disk 6 or a floppy disk connected to the service processor SVP to the control storages SC21 of respective processors. Thus, the loading of the micro programs for respective processors is attained at high speed without passing through the main storage device MS of the service processor SVP.