An electronic control for damping oscillation of a swinging backhoe assembly includes a crossover valve that connects the hydraulic lines that supply hydraulic fluid to the boom swing cylinders to each other whenever an electronic controller senses incipient oscillation or swinging of the backhoe assembly. In one embodiment, an optical source and detector are positioned on opposite sides of the media path, at an acute, non-zero angle with respect to a direction normal to the media path. The apparatus further includes a drive unit configured to actuate movement of the drive member by selectively coupling to the drive member, wherein the coupling of the device to the drive member is controlled by applying an energy to a selected material in the device. The load driver drives a load based on the driving voltage and the driving signal. In this manner, power consumption in the entire chassis can be managed such that all server blades can be powered on and operate at higher steady-state utilization. The link mechanism is driven by the crank wheels as to move forward and rearward the slide seat.