Electrophoresis display devices using charged particles which move in each cell in accordance with the electrophoresis caused by electrodes neighboring the cell. The circuit includes a wave guide having at least a first wall and a second wall opposite the first wall. Such methods and systems may also involve the display of the user’s screen on a dedicated monitoring display device. Embodiments further enable privileged functions which are functions that can only be accessed by a restricted set of other privileged functions. The total output current from the unary DAC cell corresponds to the combined currents from each of the current sources that are enabled.