Disclosed herein are methods and systems to provide, to a wireless communication device, a mapping between a first unsupported message type and a first supported message type. During a rewind operation, various pictures of an EP-EP segment that are decoded to display the last picture in the EP-EP segment are cached. Applications can then scale content appropriately based on the proximity data. Voltage is applied between the front electrode and the back electrode so as to change a distribution of the electrophoretic particles according to the polarity of the voltage and to form a desired image on the dispersion system. A processor reads the position signal and the detector signal and calculates blind spot boundaries based on the position signal.