In an optical communication device, a light source is capable of varying the wavelength of light to be output. The dust separation chamber is adapted to provide a generally cyclonic airflow for separating dust from a dust laden air stream, and is at a bottom of the dust separation chamber connected via an outlet to the dustbin. Based on the PPK a virtual page key is generated and stored in at least one register. A pair of water spray nozzles are disposed within the hollow seat and directed rearwardly toward the pivotal mounting for the seat. A method of the invention includes detecting that a VM managed by a hypervisor of a host machine is starting a boot up process, modifying a rate of a clock of the VM to speed up the boot up process, determining that the boot up process of the VM is complete, and returning the rate of the VM clock to a normal operational rate that is slower than the rate of the VM clock during the boot up process. The preferred embodiment also includes a cyclic control adapted to vary an orientation of the rotor blades in relation to the hub on a cyclical basis, and a horizontal stabilizer mounted on one of the pylon and the tail boom.