A originating computing system sends an electronic message to a destination computing system via a routing path that includes one or more intermediary message processing computing systems. The read out information item is reflected at a reflection point and is written back to the memory cell device at the second clock frequency. A filler wall is mounted over the side wall opening of the core section with each of the filler walls being substantially coplanar with one of the side walls. One exemplary embodiment includes photodetectors that are substantially smaller than conventional photodetectors and that are arranged into two or more groups, with the photodetectors in each group coupled to produce a single group image signal.