This invention improves the performance and lowers the cost of DC to AC inverters and the systems where these inverters are used. In one aspect, a method includes, in response to a first signal received by the storage device, performing a soft power fail operation on a first section of the storage device. One set of terminals can comprise plural connector pins and the other set of terminals can comprise plural landing pads, such that the plural connector pins and the plural landing pads make a same electrical connection regardless of the rotational orientation of the hand-held reader module relative to the sensor module. In a preferred embodiment, the display system has a randomizing device that alternates the amplifier through which an analog video signal passes. The system further monitors keyword bids at one or more paid Internet search engines to identify bid changes of interest to a potential bidder.