A fault-tolerant computer uses multiple commercial processors operating synchronously, i. A support frame provides stability for a vertical bar, which supports a winch means. A print data network connection is provided for incoming print data or copy data to be rastered. The flow guide devices of the air vents are arranged within the air distribution element, and the heat exchanger is arranged within the range of variation. The filter way weight an incident light signal by wavelength over a predetermined wavelength range according to a predetermined function so that the filter performs the dot product of the light signal and the function.