4M x 1Bit cmos dynamic RAM with fast page mode, 5V, 128ms refresh, 60ns 4M x 1Bit cmos dynamic RAM with fast page mode, 3.3V, 128ms refresh, 60ns 4M x 1Bit cmos dynamic RAM with fast page mode, 3.3V, 128ms refresh, 70ns 4M x 1Bit cmos dynamic RAM with fast page mode, 5V, 128ms refresh, 50ns 4M x 1Bit cmos dynamic RAM with fast page mode, 5V, 128ms refresh, 70ns