To enhance developing and manufacturing efficiencies of a microprocessor manufacturer without increasing a burden on a game machine developer.

A first emulation program which, if the program of a 68-type microprocessor is stored in a ROM 311, analyzes the program to execute a process corresponding to an instruction code, and a second emulation program which, when the program of a Z80-type microprocessor is stored in the ROM 311, analyzes the program to execute a process corresponding to an instruction code, are stored in an emulation program storage part 303. A logical operation unit 301 executes an action designated by the instruction code in the ROM 311, by following the first or second emulation program while the program stored in the ROM 311 is used as the program of the microprocessor designated to a designating terminal.