PURPOSE: To make it possible to execute the interruption processing by a special key operation as it is by discriminating the interruption by a normal key operation and the interruption by the special key operation and outputting the interruption signal according to the kind to an interruption control part.

CONSTITUTION: When the interruption by a normal key operation is executed by operating a keyboard 9, the key code is stored in a normal key code output register 22 and an interruption signal control part 26 outputs the interruption signal by this normal key operation to an interruption control part 12. Thus, a processor 11 executes the interruption processing by the normal key operation. When the special key code by the special key operation of the keyboard 9 is stored in a special key code output register 23, the interruption signal control part 26 outputs the keyboard interruption signal by the special key operation. Thus, the processor 11 reads the special key code from the special key code output register 23 and executes the interruption of the setting of a hardware operation mode, etc.