DIGITAL COMPUTERS, PARTS AND ELEMENTS THEREOF, ELECTRONIC DATA PROCESSING EQUIPMENT; AUTOMATIC PROGRAMMING EQUIPMENT-NAMELY, APPARATUS FOR CONTROLLING REMOTELY LOCATED ELECTRICAL DEVICES ACCORDING TO A PRESELECTED PROGRAM FROM A CENTRAL STATION BY MEANS OF PULSE MODULATED SIGNALS; COMPUTER HARDWARE-NAMELY, PERIPHERAL PROCESSORS, TEST MESSAGE GENERATORS FOR TESTING LOGIC AND/OR ARITHMETIC FUNCTIONS OF A COMPUTER, MULTIPROGRAMMING MODULES, PROGRAMMABLE SAMPLE RATE DEVICES, EVENT COUNTERS, APPARATUS FOR DATA COLLECTION, RECORDING AND TRANSMISSION, REMOTE COMMUNICATIONS PROCESSORS, AND COMMUNICATIONS ADAPTERS; MICROFILM READER/CONTROLLERS; WEIGHING DEVICES FOR GENERATING DIGITAL DATA- NAMELY, SCALES, BENCH SCALES AND CONTROLLERS THEREFOR, CONVEYOR SCALES, AND SCALE ADAPTERS, INCREMENTAL PLOTTERS; DRUM POINT RECORDERS; SIGNAL DISTORTION ANALYZERS; MINI-COMPUTERS AND CALCULATORS; MEMORY DEVICES FOR DIGITAL COMPUTER SYSTEMS-NAMELY, DISK CARTRIDGES, DISK PACKS, DISK DATA STORAGE AND DRIVE UNITS, DATA STORAGE MODULE DRIVES, CARTRIDGE DISK DRIVES, MAGNETIC MEMORY DEVICES-NAMELY, MAGNETIC CORE STORAGE, EXTENDED MAGNETIC CORE STORAGE ATTACHMENTS, MASS STORAGE CONTROLLERS, DRUM DATA MEMORY UNITS, MEMORY EXPANSION MODULES, TAPE TRANSPORTS, MEMORY STACKS, MEMORY DRUMS AND DRUM ASSEMBLIES, HEAD ASSEMBLIES FOR DRUMS, DISKS AND TAPE TRANSPORTS, AND MICRO DRUM STORAGE UNITS; CARTRIDGES AND REELS FOR PAPER TAPE AND MAGNETIC TAPE; SNAP LOCK REEL HUBS; TERMINAL DEVICES FOR DIGITAL COMPUTER SYSTEMS-NAMELY, CONVERSATIONAL DISPLAY TERMINALS, SLAVE DISPLAY TERMINALS, USER INTERACTIVE DISPLAY TERMINALS, REMOTE BATCH TERMINALS, OPERATOR CONSOLES, DIAL-OUT CONTROL CONSOLES, PLASMA DISPLAY INQUIRY TERMINALS, ON-LINE TELLER TERMINALS, BLOCK-MODE CONVERSATIONAL DISPLAY TERMINALS, BUFFERED DATA AND CONTROL TERMINALS,GRAPHIC DISPLAY KEYBOARDS,DISPLAY/ENTRY STATIONS, REMOTE TERMINAL CONTROLLERS, OUTPUT STATIONS, CATHODE RAY TUBE TERMINALS, AND ACCESSORIES, EXPANDED CATHODE RAY TUBE TERMINAL MEMORY UNITS, OPERATOR ENTRY CONTROL PANELS, REMOTE INPUT-OUTPUT STATIONS; COMPUTER INPUT AND DISPLAY EQUIPMENT COMPRISING A CATHODE RAY DISPLAY TUBE, LIGHT PEN, AND ELECTRONIC KEYBOARD, FOR OPERATOR COMMUNICATIONS WITH A COMPUTER; COMPUTER ENTRY AND DISPLAY STATION COMPRISING A CATHODE RAY DISPLAY TUBE AND ELECTRONIC KEYBOARD FOR OPERATOR COMMUNICATIONS WITH A COMPUTER; MAGNETIC TAPE, QUALITY GRADED MAGNETIC TAPE, AND MAGNETIC TAPE DEVICES FOR USE IN DIGITAL COMPUTER SYSTEMS-NAMELY, ELECTRONIC TAPE DEGAUSSERS, ELECTRONIC TAPE DUST AND MAGNETIC OXIDE REMOVERS, UNITS FOR GRADING QUALITY OF MAGNETIC TAPE, TAPE TRANSPORT CHANNEL SWITCHES, TAPE TRANSPORT CONTROLLER INTERFACES, MAGNETIC TAPE SYNCHRONIZERS; DOCUMENT READING DEVICES FOR DIGITAL COMPUTER SYSTEMS-NAMELY, PAGE READERS, DOCUMENT READERS, DOCUMENT READER/SORTERS, CARD READERS, BADGE READERS: COMMUNICATIONS DEVICES AND SYSTEMS-NAMELY, COMMUNICATIONS MULTIPLEXERS, ANALOG-TO- DIGITAL AND DIGITAL-TO-ANALOG CONVERTERS, DATA MODEMS, MESSAGE CONCENTRATION TERMINALS, TRUNKLINE ADAPTERS AND CONTROLLERS, PROTECTED MESSAGE EXCHANGES, TELEMETRY INTERFACE DEVICES, COMMUNICATIONS STATIONS FOR DIGITAL COMPUTERS, DATA SET TERMINAL CONTROLLERS, DATA SET TRANSCEIVERS, DISTRIBUTIVE DATA PATH DEVICES, DATA CHANNEL CONVERTERS, DATA CHANNEL UNITS, CHAINING BUFFER CHANNEL UNITS, LINE SYNCHRONIZED TIMING UNITS, COMMUNICATION CYCLIC ENCODERS, ANALOG INTERFACE DEVICES, DRY CONTACT RELAY MULTIPLEX FILTERS, MULTIPLEXERS, TELEMETRY SYSTEMS, REMOTE CONTROL TELEMETRY SYSTEMS, MULTIBUFFER TERMINAL CONTROLLERS, DATA SET ADAPTER/POLLER, TELEGRAPHIC LEVEL CONVERTERS, DATA CHANNEL COUPLERS; ELECTRICAL APPARATUS FOR THE TRANSMISSION SYSTEMS FOR THE PURPOSE OF DETECTION, MEASUREMENT, CONTROL OR RECORDING OF LIQUID LEVEL OR PRESSURE OR GAS PRESSURE FOR USE IN WATER SYSTEMS, SEWAGE SYSTEMS, AND INDUSTRIAL PROCESSING SYSTEMS; AUTOMATIC ELECTRICAL CONTROLS FOR LIQUID DISTRIBUTION SYSTEMS, FOR MATERIAL HANDLING SYSTEMS AND FOR AIR AND WATER POLLUTION MONITORING SYSTEMS, ELECTRICAL APPARATUS FOR MEASUREMENT AND CONTROL OF FLUID PRESSURE AND LUQUID LEVEL, AUTOMATIC ELECTRICAL PROTECTIVE ALARM AND DETECTION SYSTEMS, ALTERNATORS FOR CONTROLLING THE SEQUENCE OF OPERATION OF ELECTRICAL EQUIPMENT, AND ELECTRICAL APPARATUS FOR MONITORING AND TRANSMITTING ELECTRICAL IMPULSES USED IN CONJUNCTION WITH SAID CONTROLS, APPARATUS AND SYSTEMS; ELECTRICAL TEST EQUIPMENT-NAMELY, CIRCUIT BOARD TEST EQUIPMENT, VIBRATION ANALYZERS; OPTICAL CHARACTER RECOGNITION DEVICES-NAMELY, READERS AND CONTROLLERS; CARD PUNCHES; DISK STORAGE UNIT EXERCISERS; INQUIRE/RETRIEVAL CONTROLLERS; COMPUTER INTERFACED OPERATOR INTERACTIVE GRAPHIC SYSTEMS; COMPUTER SYSTEM STALL ALARM; LOGGING TYPEWRITER INTERFACES; TYPEWRITER INTERFACE; KEYBOARD ASSEMBLIES FOR ELECTRONIC EQUIPMENT; PAPER TAPE RECORDERS; DIGITAL INPUT INTERFACES; DIGITAL INPUT SYNCHRONIZER UNITS; INTERRUPT SIGNAL CONDITIONERS; INTERRUPT INTERFACES; ELECTRONIC COUNTERS; LOGIC APPARATUS-NAMELY, ENCODERS, DECODERS, REGISTERS, ADDERS AND ACCUMULATORS, SUBTRACTORS, AND FIXED AND FLOATING POINT MULTIPLIERS AND DIVIDERS; DIGITAL OUTPUT UNITS, ANALOG OUTPUT UNITS; DIGITAL DISPLAY UNITS; LATCH RELAY OUTPUT INTERFACES; LATCH RELAY OUTPUT UNITS; ANALOG INPUT SIGNAL CONDITIONERS; DIGITAL INPUT SIGNAL CONDITIONERS; SAMPLE AND HOLD CIRCUIT FOR MONITORING VARIABLE VOLTAGES;ELECTRONIC CIRCUIT MODULES; COMPUTERIZED ALPHANUMERIC DATA PREPARATION SYSTEMS; ELECTRICAL LIQUID CONTACT SENSING DEVICES; INDUCTION AND ELECTRONIC LIQUID LEVEL CONTROLS; CONTROL SYSTEM INDICATOR PANELS PICTORIALLY INDICATING LIQUID FLOW CONTROL SYSTEM LAYOUTS AND LOCATIONS AND OPERATING CONDITIONS AT THE CONTROL POINTS, SUCH AS TEMPERATURE, PRESSURE, FLOW VOLUME AND OPERATION; TIMING DEVICES ASSOCIATED WITH DIGITAL COMPUTERS-NAMELY, REAL TIME DEVICES, TIME BASE SOURCE DEVICES, AND INTERRUPT CLOCK DEVICES; AMPLIFIERS AND FILTERS- NAMELY, DEFLECTION, ENCODER, VIDEO AND RECORD AMPLIFIERS; BUFFER CIRCUITS; DELAY LINES; POWER SUPPLIES; ARC AND NOISE SUPPRESSORS; PRINTED CIRCUIT BOARDS, CIRCUIT MODULES INTEGRATED CIRCUITS, CONNECTORS, CABLE CONNECTORS; ELECTRIC PUMP MOTOR CONTROLS; SPEED CONTROLS INCLUDING MOTOR STARTING SWITCHES, AND BREAKER SWITCHES TRANSMITTERS; RECEIVERS; TRANSCEIVERS; LOAD CONTROLS FOR POWER LINES COMPRISING ELECTRONIC TRANSMITTERS FOR IMPRESSING SIGNALS ON THE LINES AND ELECTRONIC RECEIVERS RESPONSIVE TO SUCH SIGNALS AND SERVING TO CONTROL CERTAIN LOADS ON THE LINES; AUTOMATIC ELECTRIC HYDROPNEUMATIC PUMP CONTROL FOR PRESSURE TANKS; FEEDBACK CONTROL SYSTEMS FOR PRESSURIZED CONDUITS; ALARMS FOR ELECTRICAL APPARATUS