Abstract: In a system for driving a plasma display panel, predetermined different values of the discharge voltage are selected corresponding to predetermined different ranges of the ratio of the number of discharging spots to the number of the entire spots of said plasma display panel.

Abstract: A method and an apparatus for determining coordinates in a self-shift type gas discharge panel by means of a light pen, the panel comprising a group of X electrodes connected in common at periodic intervals and a group of Y electrodes crossing said X electrodes. The Y electrodes comprise display Y electrodes and scanning Y electrodes, and detection with the light pen is performed by shifting discharge spots along the scanning Y electrodes by shift pulses applied to the X electrodes.

Abstract: A system for controlling a gas discharge display device having column electrodes periodically connected, a plurality of bus-lines; row electrodes connected in common and arranged transversely to and facing the column electrodes across a discharge gap, WRITE electrodes arranged at one or both ends of the row electrodes, a driver to apply shift pulses sequentially to the plurality of bus-lines, a WRITE driver to apply write pulses to the WRITE electrodes, and a control circuit to reverse the order of the shift pulses. Information is written into the device by selecting WRITE electrodes at one or both ends of each row electrode, and the shift direction of the written information is controlled by reversing the order of the shift pulses which are applied to the bus-lines by means of the control circuit.