PURPOSE: To realize the continuous transfer of data on an optional rectangular area by calculating and setting easily the number of addresses and the offset value despite the changes of the size of a display memory, the arrangement of address, the size of the rectangular area, and the method of transfer respectively.

CONSTITUTION: The data on a rectangular area are transferred continuously and vertically or horizontally. Then, the offset value is set as a 1st offset regis ter 9 so that the addresses equal to a single character are moved toward the transfer direction (vertical or horizontal). While the offset value is set at a 2nd offset register 10 so that the final address of a certain row is moved to the first address of the next row. Thus, it is possible to easily perform the continuous transfer of data on an optional rectangular area which are turned into the discontinuous addresses on a display memory 2.