Computer system with monochrome display unit capable of converting color code to gradation code

摘要

A circuit for converting a color code to a gradation code includes a detector for detecting the number of color codes to used in display of one frame from a series of input color codes, a gradation code assigning unit for assigning gradation codes having substantially the same gray level differences to the color codes to be used in accordance with the detected number of color codes, and a gradation code output unit for outputting, in accordance with each of the input color codes, a gradation code assigned to the color code. The gradation has n levels. If the number of color codes to be used is m (m