PURPOSE: To shorten the loading time of a main memory unit by previously linking and registering a program loaded into an auxiliary memory unit and another program used by referring to the program.

CONSTITUTION: Auxiliary memory unit 3 cnsists of files (1), (2) and (3); file (1) possesses a group of program A, program AB and program BB, program B and program Z, file (2) has a group of program B and program BB, and file (3) has program BA and program BB. Program A and program AB, while registered in auxiliary memory unit 3, are linked together and program AB and program BB are similarly linked together. When a request for loading program A is made, a program loop of programs A, AB and BB is all loaded into the main memory unit and processing is started.