A conductor-insulator-semiconductor (CIS) structure for a random access surface charge memory system is disclosed. The memory system comprises an array of memory cells including charge storage regions, charge transfer regions and charge receive-source regions formed along the surface-adjacent portions of a semiconductor substrate. A charge-storage line insulatingly overlies the storage regions of a row of memory cells and a bit line, comprising an extended region of opposite-conductivity-type, interconnects the receive-source regions of the same memory cells. Addressing in the Y-direction (word selection) is provided by charge transfer lines insulatingly overlying the charge transfer regions of a column of memory cells. Selected memory cells are addressed for read and write purposes by first activating the word select line which makes available one cell in each row of the memory. The desired row is then selected by means external to the array of memory cells. All cells of the selected word line are refreshed, but only one cell is addressed for read and write purposes. Means for reading, writing and refreshing data in the memory system are also disclosed.