To decode a composite VLIW packet, assembly code is provided for the bit patterns corresponding to each individual instruction in the packet. The cooling assembly has a first cooling volume, which encompasses the vessel assembly, and a second cooling volume, which jackets the vessel assembly. Thus, the workpiece is pressed by the two auxiliary rollers so that the workpiece is moved forward at a constant speed without acceleration during the grinding process of the sand belt, thereby enhancing the grinding effect of the sand belt on the workpiece. Another embodiment of the modular control system uses a driver interface unit for controlling air control units through wire applications.