PROGRAM UPDATING METHOD

PROBLEM TO BE SOLVED: To update a program with no dependence on an operating system by changing the unupdated routine link information on a routine link table into the updated link information out of a program against the program under execution. SOLUTION: When the control is shifted to a routine B from a routine A, the routine A does not directly call the routine B and asks a management routine X to execute the routine B. If the function of the routine B is changed to that of a routine B', a management routine Y of a differential program 2 sends an updating request to the routine X for a routine link table T. At the same time, the routine Y sends the information showing that the routine B' substitutes for the routine B in a program 1 and also the address value of the routine B'. Receiving these information and address value, the routine X updates the address of the routine B of the table T into the address of the routine B'.