PURPOSE: To secure effective display through an interrelation even for the picture element information of different picture element capacities, by dividing a picture into N×M blocks corresponding to the addresses of the picture memory.

CONSTITUTION: Picture memory 11 consists of N×M blocks composed of n×m picture elements. With supply of the address designation signal to multiplexer 12 from CPU, multiplexer 12 is analyzed into the row and column addresses to carry out the address designation for memory 11. Through this address designation, the picture information representing the n×m picture elements of the block are written into each address from CPU through the address designation like (0,0), (0,1), (1,0) and (1,1) and then read out by the scanning clock synchronized with the display scan of the monitor. Thus, the effective display is ensured through an interrelation even for the picture information of different picture element capacities