PURPOSE: To display a console screen and a graphic screen in colors at the same time so that they are distinctive by allocating planes constituting a frame buffer to the console screen and graphic screen and setting color component information, generated by exclusively ORing pieces of color component information of the both, in a look-up table as colors which can be displayed at the same time.

CONSTITUTION: A display color setting means 2 sets the color component information, generated by exclusively ORing the color component information written in ≥3 planes of the frame buffer FRB 5 used for the console screen and the color component information written in ≥3 planes of the FRB 5 used for the graphic screen, in the color look-up table LUT 6 as the colors which can be displayed at the same time. A console screen generating means 3 writes the color component information of a console screen image in the ≥2 planes of the FRB 5 used for the console screen and a graphic screen generating means 4 writes the color component information of a graphic screen image in the ≥3 planes of the FRB 5 used for the graphic screen. Consequently, they can be displayed distinctively in colors at the same time.