Abstract: The present invention relates to a method and apparatus for verifying the correct performance of software on an electrical system by use of a cycle-based simulator. More specifically, it relates to an apparatus and method for simulating an electrical interconnection between two electronic subsystems, or modules, within a cycle based simulator. Two separate devices, a hardware output's driver and a hardware input's receiver, are characterized as one type of simulated object, a node, and the interconnection between the two devices as a second type of simulated object, a wire. The activity of output nodes is limited to placing signal values on the wire. Input nodes have a characteristic behavior in response to the information from output nodes. The wire is enhanced by storage and comparison functions that allow the comparison between new and current values of output signals as well as identification of the cycle associated with a particular change.