A system for controlling movement of a cursor on a display device, the system comprising: a substrate having a position-coding pattern disposed on or in a surface thereof; a sensing device comprising: an image sensor for optically imaging the position-coding pattern; and a processor configured for: generating absolute motion data by determining a plurality of absolute positions of the sensing device relative to the surface using the imaged position-coding pattern; generating orientation data indicative of an orientation of the sensing device relative to the substrate; and using the orientation data to translate the absolute motion data into relative motion data, said relative motion data being indicative of relative motion of the sensing device from the perspective of a user; and communication means for communicating the relative motion data to a computer system; and the computer system configured for: receiving said relative motion data from the sensing device; interpreting said relative motion data as cursor movement; and generating cursor control commands for said display device.