A fixture for supporting a workpiece during a machining operation. The edge detecting circuit detects an edge of an input clock signal. An outermost insulating film protecting the exposed surface of said ground layer, said film having a plurality of openings filled with metal suitable for solder ball attachment. A non-zero difference indicates multiple touches and is correlated with the spread of locations simultaneously touched on the screen. The status of the battery of each terminal which may potentially form part of the routing path of a call is reported to other terminals, whereby the routing path for a call will be decided also based on the status of the battery-charge of each terminal along the routing path.