METHOD AND DEVICE FOR MULTI-WINDOW DISPLAYING AND DRAWING

PURPOSE:To speed up display operation by discriminating whether each of small rectangular areas belonging to a clip window needs to be saved according to the contents of a control memory, substituting a high-order address generated by a linear interpolating means with a page address of the control memory, and carrying out a drawing process for a stand-by memory. CONSTITUTION:All small rectangular areas of a window W1 which are masked with other windows W2 and W3 are saved in a main storage as to the relation between the masked areas and small rectangular areas. For small rectangular areas which need not be saved, the linear interpolating means draws an image on a display frame memory and an image including areas to be hidden which need not be saved is drawn on the stand-by memory by substituting high-order addresses among addresses generated by the linear interpolating means with page addresses of the control memory. Consequently, the drawing operation is performed fast.