A semiconductor memory includes multi-mode reporting signals, a state register, and parity detectors. A lifting beam is vertically movably mounted to the base at the work station while a motor assembly moves the lifting beam between a raised and a lowered position. This is achieved by using a first principles based model combined with an ultra-sound sensor. The method of maintaining the feed system and feeder device exit pressures using gas addition or extraction with the pressure control device is also described.