Abstract: Disclosed is a non-volatile memory system which includes a first power means for providing a main power source; a read/write memory means for storing and retrieving data signals so long as power is provided; and second power means for coupling to the first power means and to the read/write memory means, the second power means including auxiliary power means for providing a second power source; the second power means further including controller means for continuously providing power to the read/write memory means from either the first power means or the auxiliary power means. In the preferred embodiment, the first power means is within a housing, said housing having a compartment for the receipt of a plug-in module, and the second power means and read/write memory means are contained within the plug-in module. Additionally, in the preferred embodiment, the memory means and the second power means exclusive of the second power source are comprised of a single integrated circuit.

Abstract: A power controller system for continuously supplying power to an auxillary plug-in module includes a separate power source within the module and a sensing circuit for determining whether the main power supply is within a valid range. The main system includes a DC main power supply which is coupled to the plug-in module. The sensing circuit tests to determine whether the main power supply is connected to the plug-in module for a predetermined period of time before switching this main power supply to the power using portions of the module. In the event of loss of the main power supply, either by the removal of the module or by switching off the main power supply, the sensing circuit detects this loss and the power controller system switches to the separate power source within the module.