A structure for interconnecting one carriage cart with another. One end of a rubber tubular gland wrapped sealingly around the outside of the second end of the tubular wall is sealed in the concrete by a radially extending cast-in anchor. Accordingly, a third TFT then turns ON, and potential of an output node rises as a clock signal reaches the level H. The sense amplifiers for the two ports are used to read from all of the second port’s bitlines.