A flat panel apparatus for and a method of addressing data storage locations (80) employs a row-scanning electron beam (76) to address simultaneously a row (120) of such storage locations and thereby store data in and read data out of them. The storage locations are defined by the overlapping areas of multiple column electrodes (62) extending in a common direction on a first substrate (82) and rows addressed by the electron beam and extending in a common direction on a second substrate (54). A layer of dielectric material (52) separate the first and the second substrates, which are positioned face-to-face and spaced-apart with the direction of the addressed rows transverse to that of the column electrodes. The column electrodes receive data drive signals. The addressing apparatus is configured so that for each storage location secondary electrons emitted by the electron beam striking the location function as an electrical switch that changes between a conducting state and a nonconducting state in response to the presence of the electron beam. The secondary electrons function to either store data in or read data out of the storage location. If the storage location includes a layer (52) of material having electro-optic properties and receives incident image-carrying light, the secondary electrons function to select and store image data across the layer and thereby provide a display system having gray scale luminance.