ViewPoint is a pointing device for hyper-text like presentations. The device supports direct manipulation on a presentation screen, and realizes effective and ease-of-use presentations in low cost.
The pointing device has a push switch. This triggers HyperCard or ToolBook's buttons on the screen to start to blink (i.e. turns black and white). On the other hand, the pointing device has a optical sensor at the tip of it, and it detects brightness on the screen.
To select a button on the screen, the speaker points a button on the screen by the pointing device, and presses the push switch. Then all buttons on the screen start to blink in different duration of black and white states. By sensing change of brightness of the pointed button, the system can identify witch button is selected by the speaker. Finally, the system emulates an action as if the HyperCard or ToolBook's button is pressed by a mouse.