Method of memory-driving a plasma display panel with write and sustain voltages set up independently of each other

In a memory drive scheme of a plasma display panel, scan pulses are sequentially applied to scan electrodes and a train of sustain pulses is applied subsequent to the scan pulses to each of the scan electrodes during a certain period of time. A non-write pulse, which offers a turn-off level only when display information directed to the display cells is of a non-display is applied to the display electrodes in synchronism with the scan pulses. A write discharge is initiated for the display cells when the display cells are brought into a display state by applying the scan pulses to the scan electrodes and maintaining the scan electrodes in a turn-on level. The display is sustained in response to the sustain pulse train applied to the scan electrode following the scan pulse and dependent on the turn-on level of the display electrode.