PURPOSE: To freely and inversely display a display direction and to realize display to a confronted opposite party.

CONSTITUTION: An input part 1 inputs code data and a data storage part 2 stores code data inputted in the input part 1. A data processing part 3 generates image data from code data stored in the data storage part 2. Image data 'A' is generated from code data A3C1H, for example. An address designation part 4 designates the address of VRAM for storing image data generated in the data processing part 3 in VRAM 6. An address which is at left above VRAM is set to be (0, 0) and an address right below is set to be (639, 399). An address conversion part 5 switches the address of VRAM set in the address designation part 4, so that the upper/lower directions of a display content become the same as or opposite to the upper/lower directions of the key arrangement of a keyboard based on the instruction of an address conversion instruction part 8. A display part 7 displays the image data stored in VRAM 6.