Abstract: A screen of a scanning type display is divided both in the horizontal and vertical directions or abscissa and ordinate directions into a relatively large number of dots, so that the screen comprises an arrangement of dots (of the total number of the relatively large number by the relatively large number) arranged in the horizontal and vertical directions. The arrangement of dots of the screen is divided into columns each having a relatively small number of dots in the horizontal or abscissa direction. Each column is identified by a corresponding ordinal number so that the same may be the abscissa information. On the other hand, each row of each column is identified by a corresponding ordinal number so that the same may be the ordinate information. Two line buffer memories are provided for storing display control information of lines which are different by a predetermined number of lines in the vertical direction.