In a display element using cholesteric liquid crystal, to enable a high-speed partial screen rewrite, a region not to be partially rewritten is scanned in high-speed mode within the tolerance of crosstalk of the liquid crystal, and a region to be partially rewritten is partially rewritten by being scanned at a normal speed within a rewritable range with an inexpensive universal driver. The computer software implemented configuration mechanism utilizing CPU and memory of a computer system automatically generates a full configuration of the disk drives connected to system peripheral bus both at system initialization time and runtime. One or more backup paths are computed between the ingress and egress nodes, which are activatable upon a failure condition associated with the working path or the backup paths. The metal structure at least extends over an area of the second level that is defined by a projection of the at least one gap towards the second level.