Abstract: The invention relates to a photo-optical keyboard having an improved keyboard housing and keys for the purpose of confining debris and liquid spills on the keyboard. The keyboard housing has a matrix of rows and columns of apertures for keys. The housing has recesses open to the top of the keyboard between the apertures. Further, there are structural supports between the apertures which separate the recesses and cause the recesses to be reservoirs. Multiple keys are positioned in the keyboard housing apertures. Each of the keys has an umbrella cap with edges extending over the recesses. Liquid or debris spilled on the umbrella cap will fall into the recesses to be contained.

Abstract: An electronic circuit is described for providing an analog-to-digital conversion system having an output "delta" format in which a pulse is produced for each defined change in the amplitude of the input signal. The circuit is characterized by minimal hardware complexity and low current drain. In performing its conversion function, the circuit advantageously employs a single capacitor for coupling the input signal into the system as well as for storing precisely controlled voltage increments for effecting the equality of the input signal and a reference potential. The AC coupling afforded by this configuration eliminates the problems attendant with the digitization of a small AC signal superimposed on a large DC component. Additionally, the circuit of the present invention lends itself to the multiplexing of input signals.

Abstract: The invention relates to a photo-optical keyboard having an improved keyboard housing and keys. The keyboard housing is a molded plastic piece having a matrix of apertures for keys and a series of light channels passing between the apertures. The light channels open up to the underside of the keyboard housing. A spacing below the keyboard housing allows the keys in the apertures to overtravel and obstruct the light paths. Light isolation barriers beneath the keyboard housing prevent crossover of light between channels. The key is a molded plastic key with vertical slots to allow for passage of light in the undepressed state.

Abstract: The invention relates to a photo-optical keyboard having an improved keyboard housing and keys to provide an N-key rollover feature. The keyboard is comprised of a keyboard housing and keys, and may have a baseplate. The key has a pair of grooves oriented along the axis for both columns and rows to allow the passage of light regardless if the key is in the up position or the depressed position. The keyboard further contains a reset feature to synchronize keyboard logic if it becomes unsynchronized when partial key depressions are made.

Abstract: Electrostatic and magnetic transfer apparatus for conducting and magnetically attracting electronically conductive toner from the surface of a dielectric drum to a secondary substrate such as plain paper wherein a fixed permanent magnet disposed within a hollow cylindrical roller located at the image transfer point within a portion of a continuous loop of semi-conductive material supplies additional attractive force between the toner and the substrate exclusively at the image transfer point which in combination with the electrostatic transfer force applied to the imaged dielectric surface of the drum by means of a voltage potential applied to the hollow cylindrical roller, produces a dense, well defined pattern of intelligence replicating what was originally applied to the dielectric surface.

Abstract: The invention is a booster-inverter power supply circuit for providing a regulated, inverted DC output. It is made up of a conventional booster-regulator power supply circuit and improved by the addition of an inverter circuit. The conventional booster-regulator circuit includes an unregulated DC input, a booster choke for receiving the DC input, a switch for controlling the booster choke, a voltage to pulsewidth control connected to the switch for controlling the switch, an AC to DC converter for providing a DC to the voltage to pulsewidth control, and an output circuit having an output diode. The circuit is improved by the addition of the inverter circuit having an inverter transformer and a voltage control circuit. The inverter transformer is connected at one end to the switch, the booster choke, and the output diode. The switch controls the voltage on the inverter transformer. The output of the inverter transformer is a regulated AC output fed to the AC to DC converter.

Abstract: In a microprogrammed data processing pipeline system comprising a plurality of stages, microinstructions for controlling the stages are stored as templates in an addressable template micromemory store and are provided automatically and sequentially to the stage of the pipeline system. Each template is associated with an individual set of data and includes microinstructions for each stage, whether real or virtual, through which the associated set of data passes. The template micromemory store is segmented into a plurality of individually addressable micromemory units with each unit therein storing microinstructions for an individually associated stage in the data processing pipeline system.

Abstract: In a microprogrammed data processing pipeline system comprising a plurality of stages, microinstructions for controlling the stages are stored as templates in an addressable template micromemory store and are provided automatically and sequentially to the stages of the pipeline system. Operation microcode is introduced for a particular stage after the templates are issued from the micromemory store but before provision thereof to the pipeline system, thereby allowing a single template to control a plurality of different operations of a particular stage within the pipeline system. Provision is also made to freeze or inhibit the issuance of subsequent templates during the execution of excessively long operations in the particular stage.

Abstract: An alignment network between N parallel data input ports and N parallel data outputs includes a first and a second barrel switch. The first barrel switch fed by the N parallel input ports shifts the N outputs thereof and in turn feeds the N-1 input data paths of the second barrel switch according to the relationship X=k.sup.y modulo N wherein x represents the output data path ordering of the first barrel switch, y represents the input data path ordering of the second barrel switch, and k equals a primitive root of the number N. The zero (0) ordered output data path of the first barrel switch is fed directly to the zero ordered output port. The N-1 output data paths of the second barrel switch are connected to the N output ports in the reverse ordering of the connections between the output data paths of the first barrel switch and the input data paths of the second barrel switch.

Abstract: A modular modulo 3 module is provided having a plurality of input terminals for receiving in parallel two bytes of numerical data, and a plurality of output terminals for outputting the modulo 3 residue of each byte of data individually and the modulo 3 residue of the sum of the input bytes. The modulo 3 module is implemented through a plurality of first type modules which combine logically the numerical data on individual pairs of inputs and feed in turn a logrithmic array of second type modules which combine logically to generate the modulo 3 outputs.

Abstract: A pin-shaped handheld test probe particularly adapted to current mode logic levels indicates through a plurality of visual indicators HIGH, LOW, MIDRANGE, OPEN and SUPPLY VOLTAGE logic levels. Each visual indicator is controlled by the output of at least one comparator amplifier having one of two inputs resistively connected to a testing point and the other input resistively coupled to a stable reference voltage level generated by a zener stabilized precision resistor ladder network. The testing point is voltage biased to give an indication of OPEN when the test probe is attached to a pin or point which is unconnected.

Abstract: An apparatus and method for selecting the operation of digital data ports for regulating information flow between a programmable serial-bit, microinstruction processor and a multiplicity of peripheral devices connected to the processor is provided by a control pulse distribution circuit operating in conjunction with a controllable decoder circuit. Peripheral device designation instructions which may be available from the processor may define which of the ports will function, i.e., be "open", within the current processor cycle to enable communications between the processor and a device connected thereto. These designation instructions may be decoded to produce enabling signals for controlling the distribution of the timing and other associated pulses needed for the activation of a port. Operation of the selection apparatus may be as to permit data flow during a specified portion of each processor cycle.

Abstract: A high speed parallel operation, multiplication circuit is provided having a multiplier multiplexor which may function in combination with a column compressor for providing a resultant product, wherein, preferably, the multiplier multiplexor has been implemented using a modified Booth's algorithm, and wherein the column compressor operates to process every column within the same propagation delay whereby every input may create an output in essentially the same propagation time, i.e., true parallel operation requiring preferably no more than an average column propagation delay time.

Abstract: In a data processing error control system for named data, a parity check matrix and apparatus for using same provides for single error correcting of the data word and for multiple error detecting in both the data word and data name. The parity check matrix and apparatus utilize two additional parity check bits (over that required by a system using a prior art SEC/DED Hamming code) to provide protection against single bit errors, eight contiguous bit errors (i.e., hardware stuck at logical one or logical zero for the whole eight contiguous bits), similar four contiguous bit errors, and faults covering the entire data name field (which could occur, for example, if a wrong data word was fetched from memory). The parity check matrix is segmented and mated to the error correctional requirements and prevalent error modes of each field being protected. In encoding, parity check bits are generated for the combined data word and associated data name field.

Abstract: An error control system for named data functions in a hierarchical memory system environment requiring only a single error-control encoding for each data word used therein. Each level of memory in the hierarchy thereof includes a data word storage device preceded by an error checking circuit to validate and correct when possible data to be stored therein. A translator operates upon the data name of the data word to be stored to indicate the area or portion of the storage device in which the data word is to be stored. A directory table associates data names with data word locations in the storage device, and a search mechanism fed by the translator searches the directory table in the area or portion so indicated for a data word location in the storage device to store the data word. If a data word is not located in one level of memory, the next lower level of memory is searched for same.

Abstract: An alignment network having N parallel data inputs includes log.sub.2 N rounded up to the nearest integer of levels, each level therein including N selection gates for providing selectively direct through data flow and incrementally shifted or transposed data flow. The selectable shift amount in each level is equal to k.sup.2.spsp.(L-1) modulo N wherein k is relatively prime to N and is a primitive root of the rank number N, and L is the number of the level. A control signal provided to each level directs whether data flow therethrough is to be direct or transposed.

Abstract: A method and apparatus for use in air-traffic control are described for maintaining substantial registration alignment between radar video signals and associated computer generated data on a television monitor. It is a requirement of the monitor display that the radar video, such as raw radar, map video, etc., be displayed with a long time constant to show the history of the radar trails. Simultaneously, the associated computer generated data, such as vectors, alpha-numerics, etc., must be displayed properly registered with the radar video on the same monitor with a short time constant. This is necessary to avoid smearing, since the latter data moves on the monitor screen as the radar pattern changes. In accordance with the present invention, the radar and computer data are combined into a single cathode ray tube, photographed by a pair of vidicons having different time lag characteristics, and the images of the latter combined on a television monitor.

Abstract: A mail processing system is described for performing several basic functions. The first of these entails the receipt by the system of mail in single file or in small clumps which arrive synchronously or asynchronously in a random manner. Secondly, the system stores or buffers the mail in an orderly shingled fashion wherein the first batch of mail stored is the first batch to subsequently exit the buffer. Finally, the third function involves the output feeding of the shingled batch of mail from the system to further processing equipment. The system may advantageously include for some applications one or more singulators for generating from the shingled batch, a defined stream of mail pieces separated from one another. It is a significant feature of the buffer feeder system that the above-mentioned functions are interwoven such that the system is capable of receiving and storing one batch of mail while concurrently feeding out a previously stored batch.

Abstract: An improvement to carousel-type component dispensers which eliminates the requirement of operator intervention in order to access the next component required in the assembly of a work piece. Each time the operator inserts his hand in the dispenser to remove a component, he interrupts a light beam which triggers the dispenser's indexing mechanism to position itself for the next position of rotation. When the operator removes the component, the light beam path is restored and a light activated detector signals the dispenser's rotation mechanism to rotate the dispenser to the position specified by the indexing mechanism.The apparatus includes time delay circuitry which prevents the carousel from rotating while the operator's hand is in the carousel accessing a component.

Abstract: An apparatus for insertion in a communications line for providing both message integrity and message secrecy within a significant portion of existing communications networks. At the transmitter end, the apparatus receives messages from the communications line, enciphers them on a bit-by-bit basis and retransmits them onto the communications line. At the receiver end, the apparatus receives messages from the communications line, deciphers them on a bit-by-bit basis and retransmits them onto the communications line. The apparatus contains both a transmitter and receiver and is capable of full duplex operation in a bidirectional communications line. According to the invention, data is enciphered by combining the data received with the output of an algorithm, the algorithm output being responsive to data previously received and a unique key entered by the user.