Abstract: A cathode ray tube display for use in computer numerical control systems is provided with means for selectively displaying alphanumeric characters in normal size or in magnified size. An address generator is connected with the character code memory and is read out in synchronism with the sweep of the cathode ray under the control of a dot clock. The address generator includes means for selectively dividing the dot clock count by a predetermined magnification factor so that the character column address and the character row address are incremented at a reduced rate corresponding to the magnification factor. The output of the character generator is supplied through a shift register to a video amplifier to produce the dot signal. The shift rate and the rate of advance of the character generator from one dot row to the next are divided by the magnification factor for displaying the magnified character on the screen of the tube.