A general bus system is provided which combines a number of internal lines and leads them as a bundle to the terminals. The processor generates a signal indicative of rain on the surface from information contained in the captured image and optionally drives a surface cleaning apparatus in response thereto. A wheelchair with a seat, which has adjustably inclined lateral longitudinal seat supports. It is secured to the saw housing by screw fasteners that line up with threaded screw holes in the saw body housing and sawblade housing. The transmitter may send control information for each TB, which may include H-ARQ information associated TBs with the TBs.