Abstract: A system for controlling a plurality of machine tools in which the central processor communicates data transactions to and from a plurality of tool controllers, each of which is operatively associated with a machine tool. Each of the controllers comprises at least one machine tool control unit which is adapted to provide a digital output to the associated machine tool for controlling a particular tool function and/or for receiving from the machine tool a digital input indicative of a particular tool condition. The central processor has connected thereto a main multiple-channel data bus for conducting data transactions by transferring parallel bits of data to and from the processor. The system also includes a plurality of multiple-channel unit data buses, each of which is connected to one of the tool control units.

Abstract: A system for controlling a plurality of machine tools in which the central processor communicates data transactions to and from a plurality of tool controllers, each of which is operatively associated with a machine tool. Each of the controllers comprises at least one machine tool control unit which is adapted to provide a digital output to the associated machine tool for controlling a particular tool function and/or for receiving from the machine tool a digital input indicative of a particular tool condition. The central processor has connected thereto a main multiple-channel data bus for conducting data transactions by transferring parallel bits of data to and from the processor. The system also includes a plurality of multiple-channel unit data buses, each of which is connected to one of the tool control units.

Abstract: An automatic wafer loading and pre-alignment system for integrated circuit wafer-mask Aligners. A belt feed track system is employed to transport wafers from a "send" wafer storage carrier to a wafer pre-alignment station. The wafer is machanically pre-aligned with respect to the wafer chuck of the Aligner by means of a roller arm and flat-finder system. After completion of the pre-alignment process, the Aligner turntable is rotated to carry the pre-aligned wafer and chuck to the home position of the turntable and at the same time position another chuck at the pre-alignment station. If the new chuck at the pre-alignment station contains a wafer, the wafer is transported from the chuck to a "receive" wafer storage carrier by means of a belt return track system. The feed and return wafer belt track systems have a common portion between the pre-alignment station and the respective "send" and "receive" wafer storage carriers.