Category: Antecedents

History: The light pen is a unique antecedent, as it is a first attempt at touchscreen technology. It is a “penlike input device that was used with cathode-ray tube display to point at items on the screen or to draw new items or modify existing ones. The light pen had a photosensor at the tip that responded to the peak illumination that occurred when the cathode-ray tube scanning spot passed its

History: The joystick was probably the most competitive antecedent. It was   “A device for generating input signals that can cause the cursor or some other symbol to be moved rapidly about on the display screen in response to hand movements… It is a shaft, several centimeters in height, that is vertically mounted in a base and can be pulled or pushed by the fingers in any arbitrary direction. The normal

History: The keyboard was one of the first ways that humans and computers interacted. It is “an array of keys that may be captioned buttons or marked areas on a plane, each of which can cause a discrete signal or action when pressed with a finger. In current systems the operation of the key is detected and turned into a coded electrical signal; in the past mechanical coupling was used to