Abstract: An input system comprises a human machine interface device comprising a scroll device adapted to feed scroll pulses to a controller residing in the human machine interface device, for scrolling through contents on a display of a host computer. The controller is adapted and programmed to communicate with the host computer and adapted and programmed to sense, in a sequence of scroll pulses, elapsed time spans between each of a plurality of the scroll pulses resulting from a user operating a scroll device being a part of a human-machine interface device which is adapted to communicate with the host computer, and a direction of the operation of the scroll device by the user.