9 DIGITAL FLUID FLOW CONTROL VALVES, COMPUTER-CONTROLLERS FOR CONTROLLING DIGITAL FLUID FLOW CONTROL VALVES AND OTHER DIGITAL DEVICES, MANUAL CONTROLLERS FOR CONTROLLING ANALOG OR DIGITAL FLUID FLOW CONTROL VALVES RESPONSIVE TO A MANUAL SETTING, DIGITAL DRIVERS FOR ACTUATING DIGITAL FLUID FLOW CONTROL VALVE ELEMENTS, DIGITAL FLOW METERS, AND COMPUTER-PRESSURE CONTROLLERS