Abstract: In a display managing arrangement comprising a display memory and a display memory controller for accessing the display memory to display a selected area of an image datum with the selected area scrolled on the image datum or otherwise subjected to management, the display memory is divided into memory blocks arranged as an N-row M-column matrix. Each memory block is for use as a unit of the management and is divisible into memory elements arranged as an n-row m-column matrix.

Abstract: In an image rotating device, an input data processor processes an input signal representative of an original image into a processed signal successively representative of words wherein bits representative of picture elements of the original image are arranged according to an angle of rotation of 90.degree., 180.degree., or 270.degree. which should be given to the original image. When the rotation is 90.degree. or 270.degree., a block of bits is set in a shift register array which successively produces groups of bits. The groups of bits are stored in a random access memory and then read therefrom as successive group sets in a predetermined manner. An output data processor processes the group sets into an output signal representative of a desired rotated output image. When the rotation is 180.degree., the processed signal is processed by the output data processor directly into the output signal.