An electronic pen for recording motion data relating to use of the pen. It includes a pen body and a ball mounted in the pen body. A sensor in the pen body, located proximate the ball, detects motion of the ball and converts the motion into corresponding electronic signals. A memory in the pen body, electronically coupled to the sensor, receives the electronic signals and stores corresponding data related to the motion. Use of a high-density memory, such as an atomic resolution storage memory, permits recording sufficient data for the motion within a memory module small enough to fit within the pen body.