A programmable logic device has a plurality of super-regions of programmable circuitry disposed on the device in a two-dimensional array of such super-regions. The element is produced while held in a novel vacuum chuck, whose support surface has a width in the radial direction significantly less than the size of the element, and which is aspherically machined to match the aspheric first surface of the element. An abutment for engaging the end of the keyboard member remote from the display is located at a distance of and faces the fastener structure when in operative position for fastening the docking station to the support structure. Where a high level of coupling is present, transmission points can be included in a common cluster.