Circuit for converting digital signals representing color information into analog voltage level signals with enhanced contrast between foreground and background

Circuit means for converting digital signals representing color information into analog voltage level signals for application to a monochrome CRT monitor, characterized by a resistor network (R1 to R4) to which said digital signals are applied during operation, said resistor network (R1 to R4) being arranged to generate a voltage output in response to said digital signals, said voltage output determining the analog voltage level signals for application to said monitor, and by further resistor means (R5) to which is applied during operation a further digital signal indicative of whether foreground information or background is to be displayed, said further resistor means (R5) being operatively connected to said resistor network (R1 to R4) and the ohmic value of said further resistor means (R5) being so chosen that a relative shift is brought about between the voltage range within which said analog voltage level signals lie when foreground information is to be displayed and the voltage range within which said analog voltage level signals lie when the background is to be displayed, said shift being in such a sense as to enhance the contrast between foreground information and the background.