A filter circuit includes two parallel digital filters, a DAC, and an LPF. In other embodiments, rotary gates or sliding gates within manifolds cause fuel to flow into and out of all three groups directly during a purge. An estimated spectral shape for an input signal is derived. Digital data error decoding is applied if N is less than a second pre-determined threshold. For the trackball mode, a first signal connector of the trackball device and a second signal connector of the mouse device are connected to each other so that the trackball device can perform the input control operation via the mouse device. Each of these heat conductive layers are comprised of thermally conductive material configured as planar sheets, each of these heat conductive layers being coupled to at least one wire to sink heat therefrom, such as via a wire of an input cable andor output cable.