A method and associated architecture for dividing column readout circuitry in an active pixel sensor in a manner which reduces the parasitic capacitance on the readout line. The design of the head disk enclosure provides a reduced thickness in a localized region over the disks. By driving the two separate wheels in unison but with their own individual drive shafts, increased ground-engaging surface area can be obtained without a consequential increase in load for any one motor. If so, the rule engine may enable truth maintenance for the object type. The data input and output devices may be input buttons and a display on a remote control. In order to facilitate the development of image processing applications the described method provides a plurality of image processing components and a connector means for establishing connections between components selected from said plurality of components by a user, wherein the connector means automatically connects said selected components.