Abstract: The described system prevents unauthorized operation of an automotive vehicle under the control of a separable engine control module (10) and signal source or memory device (12). A wire scrambler (22) and interface module (24) are interconnected between the engine control module (10) and memory device (12). A key device (20) having a fixed coded signal source (53) on being received within a lock cylinder (26) energizes a crossbar switch matrix (44) in the interface module (24) which effectively provides a correct wiring relationship between the engine control module (10) and the memory device (12). Connector parts (16, 30) are secured together in a manner that would destroy connector contacts if separated.

Abstract: The invention comprises an improved cross-connect switch constructed from a plurality of switch modules for connecting input lines to output lines. The improved switch includes a test access system in which selected input or output lines of the cross-connect switch are utilized as test ports. The switch utilizes computer algorithms to make connections between a test port and one of the switch modules through which a path connecting specified input and output lines passes to make a bridging connection to the path.

Abstract: A cross-connect switch having different numbers of input and output lines is described. The switch is constructed from an odd number of stages. Each stage is constructed from a plurality of switch modules. Embodiments which require at most two different types of switch modules are described. Other embodiments which utilize at most two different types of switch modules are also described.