Abstract: A graphic display control apparatus displays a plurality of two-dimensional component figures respectively corresponding to a plurality of components by overlapping these component figures with each other, in a CAD system concerning the plurality of components. The graphic display control apparatus includes a component figure storage unit for storing, in advance, information about height levels of components in one-to-one correspondence to the plurality of component figures. A displayed level range input unit inputs a range of height levels of components that are the object of component figure display. A displayed figure retrieving unit retrieves and fetches the component figures, which are situated within the range of height levels input from the displayed level range input unit, from the component figure storage unit. The component figures output from the displayed figure retrieving unit are selectively displayed on a graphic display unit such as a CRT.

Abstract: A data compression processor including a first memory for storing real number data used for processing and a data compression processor for compressing the real number data read out from the first memory. The data compression processor compresses the digits of the real number data. The invention provides not only a processor which can efficiently execute processing in all fields without increasing the capacity of a memory used for processing, but can also improve the accuracy of data as a result of processing.