To enhance game performance by developing a special pattern on a two-dimensional plane, and diversifying a method of a pattern variation by a movement of a visible window.

A special pattern display device 100 has a CPU 1020 for controlling the inside of the device, and is connected to a program ROM 1040 for storing a control program, a RAM 1090 being a work area of the program and a data receiving circuit 1140 for receiving an information signal from a main control part 200. The CPU 1020 is connected to an image processing LSI 1060 for performing image processing of the special pattern, and the image processing LSI 1060 is connected to a video RAM 1080 for storing display image data, a character ROM 1180 for storing data for making an image of the special pattern and an LCD/panel interface circuit 1100 connected to an LCD panel 1120 for displaying the image of the special pattern.