To reduce the hardware of the graphics computer in size and reduce the cost of the hardware by uniting the frame buffer and the main memory into one to process graphics data in the CPU. The frame buffer is arranged in the main memory, and a DMAC used to read pixel data from the frame buffer for display, a display used to receive the pixel data and display it on a display device such as an LCD, etc., and memories used to store the procedure used by the CPU to draw the pixel data in the said frame buffer are provided for the said graphics computer. Especially, the said memories are formed so that the single function procedure and the multifunction procedure can be selected to suit the drawing object in them. In addition, the single function procedure includes the line drawing procedure that uses data tables and the multivalue expansion procedure that uses a pattern table and a mask table. Since the frame buffer and the main memory are united into one, the CPU has come to process graphics data. Thus, the graphics computer hardware has been reduced in size and the cost of the hardware has been reduced.