Abstract: The cordless static electric discharge unit for discharging static electricity from a human body into the air. The apparatus consists of a discharge unit attached to the wearer's wrist by a wrist strap. The discharge unit utilizes a radioactive source to ionize air and the flow of the ions discharges the human body. If the human body is at a positive potential with respect to ground, the negative ions flow to the human body whereas the positive ions flow from the discharge unit to a grounding point. The discharge unit is mechanically constructed such that sub-atomic particles emitted by the radioactive material are prevented from entering the human body or flowing into the surrounding air.

Abstract: A card guide for guiding a circuit card towards a connector mounted on a backplane of electronic apparatus includes a first member which is mounted on the backplane and a second member releasably joined to the first member, the second member having a slot for accommodating an edge of the card for aligning and guiding it towards the connector.

Abstract: A key switch utilizing a buckling compression spring to move a switch actuator mechanism includes a cylindrical core of resilient material located within an opening formed by the coils of the compression spring to attenuate the acoustical energy generated by the buckling and unbuckling action of the spring.

Abstract: Modems, data service units, application modules and other data communication devices, installed in a common equipment cabinet, are interconnected by way of a time division multiplexed bus. Time slots assigned to the various devices recur at a number of regularly-spaced access periods across each time division multiplex frame. The rate at which the access periods occur and the total number of access periods that make up each frame are chosen in such a way as to accommodate a mix of devices having respective bus access rates wherein there is at least one pair of rates for which neither rate of the pair is a whole number multiple of the other. The process of allocating access periods to the time slots is carried out using a known lemma to identify linear Diophantine equation solutions.

Abstract: In a processing system (FIG. 1), peripheral boards (101-103) interconnected by a stack bus with a system board (100) each have an optical emitter (163) mounted on one face and an optical detector (162) mounted on the other face. The system board has an optical emitter mounted thereon. Emitters and detectors are arranged in a daisy-chain fashion: the emitter of one board faces the detector of the next board. To assign I.D.s (e.g. addresses) to boards, the system board turns on its emitter and transmits on the bus an I.D. The adjacent board's detector is illuminated and causes the board to latch the I.D. The system board turns off its emitter, signals the adjacent board to turn on its emitter, and transmits another I.D. on the bus. The next board's detector is thus illuminated and causes the board to latch the I.D. The system board performs the procedure for each peripheral board.

Abstract: There is disclosed a message formatting arrangement which allows messages from a central processor to be distributed over a bus to a plurality of remote processors using a single address presentation for any message without regard to the byte length of the message. Each message consists of a variable number of sub-messages each having a 3-bit qualifier which specifies the sub-message type. Each remote processor is capable of determining the length of each sub-message depending jointly upon the value of the qualifier and upon the context byte which precedes each group of sub-messages. The remote processors having the capability of skipping over a variable number of idle frames without beginning to process a new message.

Abstract: Apparatus for discharging static electricity from the human body by ionizing air and utilizing the flow of ions from the apparatus into the surrounding environment to discharge the body. The apparatus utilizes two power supplies to raise two embedded electrodes positioned in a horizontal plane different voltage potentials with respect to the body. The air is ionized by utilizing discharge electrodes of the opposite polarity positioned over each of the embedded electrodes which results in air ions being formed in a ion distribution above each embedded electrode. The embedded electrodes are positioned a predetermined distance from each other in the embedded plane. Within the region between the embedded electrodes, the ions recombine to form air molecules. The ions in the distribution layers above each embedded electrode drift toward this region under attraction from each other.

Abstract: A multiprocessor system automatically responding to a request for executing a new program to establish an extended process that spans a plurality of processors each having resources required for the execution of the new program. Initially, the extended process comprises an user process that is requesting the execution of the new program. Stub processes are created as required to gain access to the object code file of the new program, to allocate a processor to execute the new program, and to initialize the allocated processor for execution for the new program.

Abstract: A frequency-hopping radio communication system is disclosed comprising a control unit which transmits to and receives from each of a plurality of slave stations using a frequency-hopping mode of operation. During a start-up mode, the control unit communicates a starting message to each slave station using a predefined frequency. The message identifies to each slave station a frequency-hopping sequence to be used to select the frequencies from a group of frequencies for transmission to and reception from the control unit. This message also specifies to each slave station unique starting frequencies in the frequency-hopping sequence at which to begin transmitting and receiving. All slave station transmissions are synchronized to the control unit transmissions, thereby preventing any two stations from concurrently using the same frequencies for either transmitting to or receiving from the control unit.

Abstract: A device separates attached multiple printed circuit boards without damaging solder connections and delicate surface mounted components attached to the boards. The device comprises a pair of disc cutters positioned in opposed alignment and minimally spaced apart for providing a bifurcated cutting edge through which commonly attached sections of the printed circuit boards are conveyed while supported by a transporter. The contact pressure on the boards is limited to the commonly attached sections as they are engaged and conveyed by the cutting edge. Minimal stress and vibrations are imparted to the boards and therefore the components connected thereon with this device. The boards are thus separated while avoiding damage to the solder connections or the surface mounted components.

Abstract: An adaptive expander for telephones reduces the gain of a transmitting amplifier in proportion to the intensity of the background noise. Gain reduction occurs when the user is not speaking into the handset microphone. When the user is speaking, however, the gain of the transmitting amplifier is restored to its normal level. Noise is distinguished from speech via long-term averaging of the microphone output signal, and a circuit that precludes the magnitude of the long-term average voltage from ever exceeding the short-term average voltage. The present invention is used in full duplex arrangements where simultaneous transmission in both directions is possible rather than in half duplex arrangements, such as a speakerphone, where transmission occurs only in one direction at a time.

Abstract: A voice-band data symbol is typically impaired by so-called phase jitter prior to symbol being received at a data modem. Modem circuitry estimates the phase angle of the jitter and an infinite-impulse-response (IIR) filter adjusts to that phase angle so that the jitter can be corrected for by a demodulator circuit. Advantageously, the IIR filter is arranged so that its pair of complex, conjugate poles are initially positioned at a first predetermined radius within a unit circle. The angular displacement of the poles around the unit circle is adaptively increased in response to receipt of a series of such estimates until such displacement substantially equals the phase angle of the jitter. The poles are then positioned at a second predetermined radius to increase the gain of the filter.

Abstract: The invention is directed to a telephone structure that eliminates the need for fasteners to assemble a keypad and secure the keypad in place in the telephone. This is accomplished by a telephone that comprises a hollow housing (100) having a face portion (120) that includes an array of holes (122) and a keypad assembly (400) that comprises a sandwich of a static shield (430), button member (410), and switch contact member (450). The keypad assembly is assembled on the underside of the housing by means of a locating member (300) which has upstanding collar portions (325) that register in the holes of the face portion and depending pins (328) that register in holes in the members of the keypad assembly. The keypad assembly is held in place by a base member (200) that is joined to the housing and supports a raised pedestal (210) that extends into close proximity with the underside of the face portion and presses the keypad assembly against the face portion (FIG. 1).

Abstract: The computational processing power of a Digital Signal Processor (DSP) in linear-phase Finite Impulse Response Filter (FIR) applications is essentially doubled by taking advantage of either the even (symmetrical) or odd (antisymmetrical) symmetry of the response of such a filter.

Abstract: Unified messaging is a concept that provides for a single electronic mailbox for different types of messages. The mailbox can be on a user's host computer, PBX, PC, etc., and the user has consistant facilities available to originate, receive and manipulate messages. Messages can be translated from one media to another for reception, and a single message may be composed of parts that use different native media. The message recipient has a single controllable point of contact where all messages can be scanned and/or viewed.

Abstract: An electronic circuit board electrically connected to other circuits of a data processing system by means of a bus, may be removed and re-inserted in the system without the necessity of disabling other circuits connected to the bus. A latch actuated switch provides a control signal in anticipation of circuit board removal. The control signal activates a finite state machine which seizes control of the bus after completion of any current bus communications and stops the generation of clock pulses normally required in bus communications. When contact is physically broken between the board and its corresponding connector, the finite state machine restores the bus clock pulses and relinquishes control of the bus. When a board is to be inserted in an open connector, contact between the board and the connector is sensed by the finite state machine which causes the bus to be seized and the bus clock pulses to be temporarily inhibited.

Abstract: In a data transmission system using a predetermined trellis code, the output signal points are selected from a predetermined alphabet representing (k+n)-bit input words by using the values of n bits of each input word, and bits from previous input words, to identify a particular one of 2.sup.m subsets of the signaling alphabet m>n. The other k bits of the input word identify a pair of signal points of the identified subset. The sum of the components of one point of each pair is no less than zero and the sum of the components of the other point of that pair is no greater than zero. A running sum of the components of the signal points previously generated is maintained. If at any point in time the running sum is greater than zero, the signal point of the identified pair whose component sum is no greater than zero is generated, and vice versa. This scheme provides a channel-coded signal having a spectral null at dc.