To reduce the hardware of the graphics computer in size and reduce the cost of the hardware, the frame buffer and the main memory are united into one unit to process graphics data in the CPU. The frame buffer is arranged in the main memory, and the graphics computer includes 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. Especially, the said memories are formed so that a single function procedure and 2 multifunction procedure can be selected to suit the drawing object. In addition, the single function procedure includes 2 line drawing procedure that uses data tables and 2 multivalue expansion procedure that uses a pattern table and a mask table. Since the frame buffer and the main memory are united into one unit, the CPU can be used to process graphics data. Thus, the graphics computer hardware is reduced in size and the cost of the hardware is reduced.