A touch screen control system comprising a memory and control circuitry is configured to communicate with a host processing system. The control circuitry comprises a blended image generator and a display screen updater, and operates a touch sensor for detecting user input in a sensing region of the touch sensor. The sensing region overlaps a display screen. In response to detection of user input in the sensing region, the blended image generator autonomously generates a blended image by blending primary image and secondary images held in the memory. The display screen updater autonomously updates the display screen with the blended image. The display screen is updated at a higher rate when updated autonomously by the display screen updater than when directed by the host processing system. The autonomous updating of the display screen by the display screen updater reduces processing of the host processing system.