A method and apparatus for continuously updating a display of the coordinates of a light pen

摘要

© A method and apparatus for continuously updating a display of the coordinates of a light pen as it moves across a display screen involves executing a single iteration of an approximation calculation every refresh cycle of the display. The absolute screen cooridnates are updated by the light pen tracking system and converted to application parameters written by the host computer into the display buffer work space. The orthogonal displacements, dx and dy, from a fixed reference point are determined. The distance and direction values from the reference point are converted to character form and inserted in the display buffer.