Abstract: An inventory control system in which local units having inventories continually and serially transmit data only in a local area to users having portable receivers which store and display when requested the inventory status of a particular item. The local units also transmit to a central computer their current inventory status so that additional local units may request inventory status in another local area from the central computer.

Abstract: A method for use in forming thin film patterns in the fabrication of integrated circuits. The method involves depositing a bottom layer of positive photoresist material on a substrate, and forming over the bottom layer, a discrete light-transparent top layer of positive photoresist material which is less solubilized in developer after exposure to light than is the material in the bottom layer. The top and bottom layers are preferably separated by an intermediate layer of a light-transparent polymeric material which is immiscible in the bottom layer and unaffected by the subsequently applied top layer.The composite structure is exposed to a selected pattern of light, e.g., through a mask, and developer for the positive photoresist material is applied to the top and bottom layers. In the case where an intermediate layer is used, the top layer is developed first.