A method and device for maintaining data coherency in a semiconductor memory device, having two or more memory chips combined into one chip and operated according to a late select synchronous pipeline type inputoutput protocol. In response to a first predetermined input, the control means moves at least two of the plurality of first windows displayed on the first display means from the first display means onto the second display means. An additional metal powder can be de-oxidation sintered onto the connection region to form the electrode. From the benzene distillation column, a first benzene recycle stream is removed as overhead; a second benzene recycle stream is removed as a side draw; and a bottoms stream comprising polyisopropylbenzene, cumene, and heavy aromatics is removed from an end.