A system for use with a computer is provided, the computer including a self-encrypting drive, the SED including a nominal space and a pre-boot region, wherein the nominal space can be locked to prevent access to the nominal space. After initialization, the dynamics of a chaotic system are allowed to generate the 0 and 1 bits of a key bistream. In one example, Internet bound traffic can be directly routed to the Internet, without employing macro network resources. The rear interface unit may include a switch activated by the post for disconnecting two of the rear connectors of the module when the jack is mounted to the module and engaged with the rear interface unit. The object is to build a tower as high as possible without having the tower fall over. Membrane air generates an air lift which drives the mixed liquor circulation.