The invention relates to a system including a machine capable of retrieving data from a recording medium and of executing a program retrieved from the recording medium in response to an instruction given by an operator to the machine. Particularly, the invention relates to a system which comprises of such machine and a control unit connected to the machine for controlling the machine. The control unit includes: a housing; a pair of diverging grips which are molded integral with said housing and are supportable by both palms of the operator; a plurality of finger-manipulatable controllers mounted on the housing; and a vibration motor mounted within at least one of the grips via a adapter. The vibration motor includes: a casing; a freely rotatable shaft supported by the casing; an eccentric member, mounted on the shaft, having a rotor mounted on the shaft and a plurality of coils mounted on the rotor. Accordingly, when the coils are activated by the electric current, the motor is set in vibration caused by the rotation of the eccentric member. The vibrations of the motor is transmitted to the operator via the grips, thereby providing the operator with enhance virtual reality in the game.