is turned off that is set to the auto mode the switch 32 is actuated in response to the power on or system reset and the flop flop 33 is set while the flip flop 35 is set because the output of an inverter in30 is high thus an and gate a30 is opened so that the content of the register 39 is sent to the register 40 through an or gate 031 to initiate the initial program loading when the mode switch 31 is turned on on the other hand that is set to the manual mode and the switch 361 for designating memory damping is turned on the switch 32 is actuated in response to the power on or system reset and the flip flop 33 is set while the flip flop 34 is set because the output of the switch 32 is high thus an and gate a31 which is associated with the on state switch 361 is opened so that the content of the register 381 is sent to the register 40 through the or gates 030 and 031 to initiate memory damping fig2 shows another embodiment of the present invention which differs from that of fig1 in that a timer mechanism 9 is connected to the interface base line 8 in the above arrangement when the power on or system reset is keyed in the timer mechanism 9 first starts to operate the timer mechanism 9 counts.