In accordance with the invention there is provided a set of parts for providing a window blind. 3\u2266DoDjmax for Do in the interval 1; 3 in mm and 0. The switch assembly includes a miniature reed switch and a miniature latching magnet affixed directly to one of the reeds or the associated lead wire. Furthermore, the method comprises reading third and fourth input data values from locations of the second buffer, the locations being determined by third and fourth read addresses determined by swapping at least two of the bits of the first and second read indices respectively.