Abstract: Under a transparent board-like digitizer, a screen of the same size as that of the digitizer is positioned. Scenes of a display device is shown on the screen. A co-ordinates standard of the digitizer is set to be identical with that of the screen. Consequently, the point indicated on the digitizer of a first cursor device is shown at a position corresponding to that of the point indicated by means of the cursor. In a circle drawing mode of the digitizer, when the operator places the cursor device on the digitizer and co-ordinates data are inputted to a computer, a plot circle corresponding to the co-ordinates data is displayed on the screen. When the operator makes the plot circle by means of the cursor device, the computer selects a radial input system. On the other hand, when the operator uses the cursor device and selects the exterior of the plot circle, a transient point input system is selected.

Abstract: A transparent board-like digitizer is placed near a display screen. Images of the same size as that of the digitizer images entered on the digitizer are displayed on the screen. A co-ordinates standard of the digitizer is set to be identical with that of the screen. Thereby, the point indicated on the digitizer of a first cursor device is shown at a position corresponding to that of the point indicated by the cursor. The screen displays right-angle scale lines controlled by a second cursor device on the digitizer. The right-angle scale lines can carry out parallel movements and rotations on the screen.

Abstract: In a reader in which a tablet and a cursor device are connected electrically to the reader and an indicated position of the cursor device on the tablet is converted to a coordinate signal to be outputted, the improved reader in which two cursor devices are connected to the reader, and the first cursor device is retained by one hand, and the second cursor device is retained by the other hand, and the two cursor devices are manipulated by both hands of the operator so as to shift them on the tablet whereby the reader outputs the coordinate signal for the drawing of a graphic, and setting the command to a CPU on the basis of the indication of each cursor device.