the example of fig1 in which data is read out of the pallet 2142 at the mpu read access the output data 2037 is delivered by switching between the pallet output data 2028 and the interpolated data 2048 however the pallet which is read out for the mpu read access and the pallet output data to be entered to the selector are not confined to the manner of this embodiment however the circuit arrangement of this embodiment is effective only for monochrome display data and it cannot deal with color display data the seventh embodiment of this invention is the arrangement of the display data selector 34 as shown in fig1 for the display controller of the sixth embodiment the timing chart of fig1 c also shows the display operation based on the display data selector of fig1 the seventh embodiment differs from the sixth embodiment in the display data selector 2034 which is intended for color display data in contrast to that of the preceding embodiment for monochrome display data color display data consists of three color components including red r green g and blue b as shown in fig1 on this account display data interpolation circuits 2047 are provided to deal with the r g and b components independently for a read access to the pallet 2142 during the display period data 2481 2482 and 2483 produced by interpolation for the r g and b components of output data 2029 2027 and 2026 of pallets which are.