shows an operator 39 s switch provided with the rotary knob 20 during the operation of the mini computer 1 the communicating device 5 displays the flow of information through control section 4 the time axis controller 6 is driven by the control section 4 on one hand and controlled by the knob 20 manipulated by the operator on the other hand for sending a timing pulse to the control section 4 whereby the control section 4 functions to adjust the timing in other words the flow of information to be displayed by the communicating device 5 maybe adjusted by the operator for this reason by manipulating the operator 39 s switch 9 it is possible to vary the speed of the progress of the operation which is to be displayed by the communicating device 5 by adjusting the time axis controller 6 when the operator wishes to read accurately the progress of the operation which is displayed by the communication device 5 he turns the knob 20 toward 34 slow 34 thereby decelerating the operating speed of the time axis controller 6 thus displaying at a lower speed the progress of the operation one example of the time axis controller 6 shown in fig3 which characterizes the invention comprises an up counter 61 connected to receive an electric pulse from a pulse generator 62 through an and gate circuit 63 whose other input is connected to receive a control signal from the mini computer an up down counter 65 connected to supply a signal to the up counter 61 through a gate circuit 64 and a gate circuit 66 controlled by a control signal from the mini computer for supplying a signal from a center processor not shown of the mini.