An electric-motor assembly for installation in a borehole to power a downhole tools such as a pump has a first impermeable tube defining an axis and a stator fixed in the tube and having a series of coiled windings and laminations and electrically insulating potting in which the laminations and windings are imbedded. The engine also comprises an oil pump and a water pump. Data for each item includes an item component and an information component, wherein the item component communicates to an operator viewing a video display which item is associated with the information component and its relative position to the operator, and the information component communicates to an operator the information associated with the item. A result of the executed error diffusion is outputted. From a lower face of the datum plate extend positioning columns corresponding to the apertures defined in the radiator. The signal strength message may cause the base station to adjust a power with which signals are emitted from the base station such that the signals satisfy the acceptable signal strength at the target location.