a method and circuit for operating a gaseous discharge device which , in one form , comprises a plurality of discrete gas cells , each having its own cathode and anode electrodes arrayed in a matrix such that the cells can be activated and sustained in different groupings to represent different characters . the gas cells may be small - area light sources arrayed in rows and columns , with each row of cells having a common cathode electrode , and each column of cells having a common anode electrode . each cell can be turned on , and caused to strike a glow discharge , by having the required firing potential applied between its anode and cathode electrodes . cells which have been thus turned on can be kept on , so as to impart a storage or memory characteristic to the matrix , by means of sustaining pulses applied directly to their anodes and cathodes , with no intervening current - limiting impedances being required . the desired operation , that is , the sustaining of glow discharge at a controlled level of current flow and light output , is achieved by properly tailoring the parameters of the sustaining pulses , that is , their amplitude , time duration , and repetition rate .