Abstract: An FSK demodulator of the differential type is arranged to provide two versions of an input FSK signal that, relative each other, (1) have a linear phase shift versus frequency characteristic and (2) are phase shifted by 90 degrees at a center frequency halfway between the upper and lower FSK frequencies. The linear phase shift is provided by an N sample delay element, while a constant phase shift circuit which includes a K factor gain element provides the 90 degree phase shift. By virtue of this arrangement, the demodulator characteristics can be adaptively varied and the demodulator tuned simply by changing the value of K. A similar adaptive technique is applied to a threshold detector arranged to position a threshold midway between the extremes of an input signal.

Abstract: The adjunct call processing arrangement of our invention eliminates the separation between hard-wired telephone switching system computer facilities and customer owned switchably connectable computer facilities. A general purpose communication interface is provided which connects the customer provided computer facilities to both the switching network and the hard-wired system processor of the telephone switching system via the standard telephone switching system port circuit. This general purpose communication interface enables a customer provided computer facility to provide additional call processing capability. In particular, the attendant services call processing subroutines and the directory assistance data base and software are provided on the computer facility. The telephone switching system routes all attendant-directed calls to a telephone station set associated with the computer and transmits call related data to the computer.

Abstract: This invention relates to line circuits and, in particular, to the apparatus contained therein for switching the ringing signal on to the communication pair which connects the line circuit to the telephone station set which it serves.Electromechanical relays provide an ideal switching function but require a significant amount of space while semiconductor switches do not require much space but provide an imperfect switching function which adversely affects the performance characteristics of the line circuit.The subject ringing apparatus makes use of a semiconductor switch to provide the ring relay function and incorporates additional circuitry to eliminate the difficulties associated with semiconductor switches.

Abstract: There is disclosed a method of setting up, manipulating, and taking down communication connections. The telephone instrument would include a graphics screen, such as a PC, and a series of call appearance boxes would be represented on the screen. Each possible party to a connection would be represented by a picture (icon generated upon request for a particular party) and an associated label (the party's name). The icon representative of a party is moved, by use of a cursor, inside a communication appearance box on the screen to place that party on the call. The icon would be moved out of the box to drop the party from the call. In this manner, two-party, as well as conference, calls can be established.

Abstract: A receiver circuit uses a switched capacitor circuit to couple either analog or digital signals received over a two lead communication facility to connected apparatus. During a first time interval, a capacitor is connected across a lead of a facility to sample the facility voltage. During a second time interval, this capacitor is disconnected from that lead and reconnected in series between the second facility lead and the input to a voltage regenerator circuit. An appropriate regenerator circuit is selected to reconstruct either the received analog or digital signals for output to connected apparatus.

Abstract: Synchronization facilities are disclosed for maintaining error free timing of a digital system when control of the system timing is switched between a plurality of clock sources. The signal of each source is applied to an associated counter divider whose output is applied to switch facilities which extend the output of only one divider at a time as a reference clock source to the digital system. The dividers for the other sources are forcibly reset each time the divider of the reference source advances from its all 1s to its reset (all 0s) position. This maintains the output signals of all dividers in phase with each other to prevent disturbances to the digital system when its timing is switched between clock sources.

Abstract: In a system for communicating primary and secondary data from a transmitter to a receiver, each of a first plurality of primary data word values is communicated by the transmitter by transmitting an individual channel symbol associated with that value, while each of at least two other primary data word values are communicated by transmitting a selected one of at least two other channel symbols associated with that primary data word value. A predetermined one of the two channel symbols associated with the first primary data word value is transmitted only when secondary data having a first value is to be communicated, and a predetermined one of the two channel symbols associated with the second primary data word value is transmitted only when secondary data having a second value is to be communicated. In the receiver, both the primary and secondary data word values are recovered from the channel symbols thus transmitted.

Abstract: A modular plug connector is adapted to terminate a cord having a number of insulated solid wire conductors. The connector includes a dielectric housing that facilitates interconnection between the solid wire conductor and a metallic terminal which slides into a terminal-receiving slot of the dielectric housing. The metallic terminal includes three tangs, or blades, that pierce the insulation surrounding the solid wire and achieve electrical contact. Adjacent tangs grasp the solid wire on opposite sides of its center line, but are controllably spread before making contact with the wire by cam surfaces molded into the side walls of the terminal-receiving slot. Reliable connections are therefore made between a metallic terminal and a solid wire conductor without severing it.

Abstract: This circuit uses a simple structure of series-parallel connected capacitors and diodes to implement an n/m voltage divider circuit. There are n columns of series connected capacitors, which columns are all connected in parallel. The capacitor valves are selected so that in each column the ratio of charging capacitance to discharging capacitance is n:m. The diodes automatically switch the capacitor charging and discharging currents to the series-parallel connected capacitors.

Abstract: A ringing signal reformatting circuit detects ringing signals having one or more ringing bursts and generates a code representing a modified distinctive ringing signal having a predetermined number of bursts and a predetermined on/off timing in response to all detected ringing signals having the same number of ringing bursts. This coded ring signal is sent to a station set and decoded thereat to generate a distinctive ring signal.

Abstract: An antenna support is provided by a molded plastic member comprising a block having a vertical passage therein, a horizontal guideway on the top of the block, and detent instrumentalities associated with such guideway. The support is designed for use with a 40 MHz wire rod antenna shaped by multiple "L" bends therein to have a middle section comprising two horizontal arms normal to each other and, at its extremities, two vertical arms normal to the middle section. The support is assembled with the antenna by passing one of the antenna's vertical arms through the vertical passage in the block, and by seating the horizontal antenna arm adjacent that vertical arm into the support guideway so that such horizontal arm is snap-fittably held in that guideway by such detent instrumentalities. Thereafter, the unit consisting of the antenna and its support is assembled with a printed wiring board so that the support maintains the antenna in a predetermined desired positioning thereof relative to the board.

Abstract: This integrated message service system provides a user with an indication of which of a plurality of message service systems contain unretrieved messages. This is accomplished by the serving telephone switching system maintaining a translation memory that indicates both the type of message services assigned to each user and the location of unretrieved messages in the assigned message services. The translation memory is updated every time a user creates a new message or accesses a previously stored message.

Abstract: In a system for communicating primary and secondary data from a transmitter to a receiver, each of a first plurality of primary data word values is communicated by transmitting an individual channel symbol associated with that value, while at least one other primary data word value is communicated by transmitting a selected one of at least two other channel symbols associated with that one other value. The selected symbol is a function of the value of an individual secondary data word. In the receiver, both the primary and secondary data word values are recovered from the channel symbols thus transmitted.

Abstract: A trunk circuit interfaces a multichannel data signal to a communication facility using a high priority queue (HPQ) memory, a low priority queue (LPQ) memory, and a data packet sorter including a separate LPQ counter for each data channel. Each LPQ channel counter keeps track of data packets from the associated channel which are stored in the LPQ memory. The packet sorter sorts data packets according to size. Small data packets from each channel which are smaller than a predetermined length are sorted for storage in the HPQ memory only when the associated LPQ channel counter is zero. Small data packets having a non-zero LPQ channel count and large data packets are stored in the LPQ memory. The trunk circuit first transmits data packets from the HPQ memory and then from the LPQ memory.

Abstract: A self-oscillating switching regulator includes an inductor which is switched across the input or output depending, respectively, on whether a control voltage does not or does exceed a predetermined threshold. The control voltage is generated from a predetermined sum of the output voltage and a voltage dependent upon the inductor current when the inductor is connected across the input.

Abstract: In a cryptographic communication system, a first encryptor transmits to a first decryptor and a second encryptor, co-located with the first decryptor, transmits to a second decryptor, which is co-located with the first encryptor. Each encryptor/decryptor pair is adapted to communicate using a selected non-self-synchronizing cryptographic mode. Whenever it is determined that synchronization between, say, the first encryptor and the first decryptor has been lost, both the first decryptor and the co-located, second encryptor are switched from the non-self-synchronizing mode to the self-synchronizing mode. This causes a loss of synchronization between the second encryptor and second decryptor since the latter is still operating in the non-self-synchronizing mode. Upon detection of this loss of synchronization, the second decryptor and the co-located, first encryptor are also switched from the non-self-synchronizing mode to the self-synchronizing mode.

Abstract: There is disclosed a speech interface circuit for use with a communication bus to interface telephone users with a computer which is also connected to the communication bus. The circuit operates to accept digital input signals over the bus from the communication processor as well as from the user and to translate these signals for the benefit of the computer. Under control of computer instructions interpreted from the translated signals, the interface transmits selected prestored speech messages to calling users.

Abstract: A flexible organizing sleeve device for ordering a plurality of elongated members such as wire and/or cables. The sleeve comprises at least two sheets of flexible material having substantially the same dimensions of width, length and thickness. The interior facing surface of each sheet has attached thereto a plurality of resealable parallel mating strips running substantially along the length of the sleeve. To install the device, a user mates the first pair of parallel mating strips and places a wire, for example, next to the mated strips between the sheets. A user then mates the next consecutive pair of parallel mating strips. The wire is now contained within a compartment-like structure. The user simply repeats the mating process of forming separate and individual compartments for each wire until the entire organizing sleeve is filled and the plurality of wires are ordered.

Abstract: A dynamic gain adjusting arrangement modifies video signals produced by image scanners to achieve high quality pictures. The arrangement compensates for amplitude distortions of the video signal caused by lens vignetting and variations in lighting conditions. The video signals are compensated for these distortions by applying continuous gain adjustment to video information generated by a photosensor and by dynamically changing the gain adjustment parameters on a line-by-line basis according to an input signal reflecting the instantaneous background level.

Abstract: A control circuit for receiving clock signals from duplicated sources, such as a pair of Time Slot Interchanges (TSI) and for normally extending the clock signal of the on-line source to clock signal utilization devices, such as digital port boards. The control circuit contains circuitry which ensures that no spurious pulses are applied to the port boards when the TSIs interchange their on-line/off-line status.