Device Driver for a Touchpad or Touch Screen Computer Input Device
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
A touchpad or touch screen is attached to a computer via a hardware interface card occupying a slot on the computer's I/O bus. This interface card interrogates the analog membrane, interrupting the CPU at regular intervals with status information and positional data, as long as the membrane is being pressed. There are two sections to the resident device driver software for a touchpad or touch screen input device. The device interrupt handler receives control for every touch on the device. It reads the status and data bytes, filters the raw X,Y data, and converts it to normalized (Image Omitted) format.