To provide a display device which is adaptable to two input devices different in input data forms with respect to the display device which receives display data transmitted from an input device and processes the received display data in accordance with programs and displays the processed display data.

A display device 10 which receives display data transmitted from the input device and processes the received display data in accordance with programs and displays the processed display data, includes a first program adapted to data transmitted from an input device 200 like a personal computer and a second program which is adapted to data transmitted from a ten key input device 400, and has the data format different from that of data transmitted from the input device 200, and it is made changeable whether the received display data should be processed in accordance with the first program or the second program.