Abstract: A data storage apparatus comprises a memory circuit including 2.sup.n1.multidot.n2 memories for storing binary information. Data of N bits from the row direction and column direction can be written and read out in parallel, and, also, such data of N bits reduced with a data reduction rate of an exponential power of 2 can be written and read out in parallel. The apparatus is used, for example, for displaying data on a display by fetching the data from common file servers connected to a private network or the like.

Abstract: A facsimile bandwidth compression method using a facsimile signal comprising a synchronizing signal part, a control signal part having digital signals made by coding signals of existence or non-existence of substantial picture information in blocks which are made by dividing the picture information signal into a specified uniform length segment, and a picture information part consisting of picture information signal of the blocks containing at least one black picture element. A reference signal having an inverted carrier phase from that of the synchronizing signal part is inserted between the synchronizing signal part and the control part. The coding of the digital signal is made by inverting the carrier phase. Guard bands having specified levels are inserted between the blocks, thereby assuring more accurate and fine synchronization than the known WBS (white block skipping) art, and hence, a very clear reproduced picture.