An N-channel transistor is provided as a switch between a high potential power line and a low potential power line. The characteristics of the system lies in that a signature which can be linked to the GTD Web 800 web pages for browsing is added into an e-mail of a user computer. The second input voltage source set provides a second input voltage set. The lubricating oil composition comprises an admixture of:. An expansion module, comprising a rotary carousel of data storage locations, can be connected to either end of the base unit which enables the robotic mechanism to access the data storage elements within the expansion module without modification.