PURPOSE: To provide a display system capable of revising the maximum number of display characters with the instruction from an application program by compressing and generating an image of a display character from a kind of font.

CONSTITUTION: When a horizontal ten characters display is performed on a display on which only eight characters are displayed, a horizontal 12 dots font is generated from the 16×16 dots font of the character of e.g. (HAN (sale)) to be displayed. The OR operation is performed between second and third dots, sixth and seventh dots, tenth and eleventh dots, fourteenth and fifteenth dots by two dots at equal intervals, and by newly generating the horizontal 12 dots font as one dot, the display of the horizontal ten characters becomes possible. At this time, two dots lines at equal intervals are set optionally. When only one kind of 16 dots font is prepared in a memory, since the display of the optional number of characters is performed by a firmware program, the information of a proper amount is displayed at high speed without increasing a cost.