Abstract: In many situations, contiguous data is not stored at contiguous locations within a memory. This fact alone causes an increase in processor time for retrieval purposes or the intervention of a memory management unit of some type. The situation is compounded when large amounts of data must be obtained from the memory or stored in the memory in real time. This problem is addressed by arranging a dual ported memory between the main memory and the processor and transferring the desired data into the dual ported memory. A pair of buffers are then used for each channel having access to the memory. While one buffer is being read, the other is being loaded. This structure also allows multiple devices to access the single main memory substantially simultaneously.

Abstract: A power transfer circuit includes first and second windings (L1, L2) sharing a common magnetic core (101). Each winding has associated with it a parallel capacitor to thus form a pair of "tank" circuits. The first winding (L1) is connected at one end to a voltage supply and, at the other end, to ground through an FET switch (100,200). The switch (100,200) is turned on and off at a predetermined frequency and at a 50% duty cycle. The second winding (L2) and associated capacitor (C2) achieves parallel resonance at the predetermined frequency. Similarly the combined first and second windings (L1,L2) and associated capacitors (C1,C2) achieve parallel resonance at said predetermined frequency. The second winding (L2) need not be electrically connected to the first winding (L1) which transfers energy to it through the magnetic core (101). The transfer circuit efficiently couples power across a dielectric interface to a pickup coil (L3).

Abstract: A communication system is arranged to provide a virtual private line facility connection to another communication system using the public switched network. In response to a predetermined signal preceding a called party dialing signal received from a user, the system accesses a virtual facility table to obtain an intersystem dialing signal necessary to establish a connection to an access line of the other communication system. The system sends the intersystem dialing signal followed by the called party dialing signal to the public switched network. The intersystem dialing signal establishes a connection to the other system which then uses the received called party dialing signal to establish a connection from that system to the called party. The virtual facility table is made accessible to speed dialing, repertory dialing, station message detail recording and automatic route selection features of the system.

Abstract: A voiceband data signal comprised of frequency-division-multiplexed primary and secondary channels is applied to the receiver portion of a modem. Circuitry within the modem for recovering the primary channel data includes an anti-aliasing filter, A/D converter, Hilbert filter, demodulator, fractionally-spaced equalizer, carrier recovery circuit and decision circuit. An error signal put out by the decision circuit is used by the equalizer to update its coefficients, and thus its transfer function. Rather than using a bandpass filter to remove the secondary channel energy prior to sampling and equalization, the receiver relies on the fractionally-spaced equalizer to suppress the secondary channel energy.

Abstract: The communication facilities access control arrangement of the telephone munication system detects the dialing of an unauthorized or invalid long distance transmission facility access code and identifies the calling station. A record is maintained of all invalid attempts to access the long distance facilities. When the number of invalid attempts by a calling station exceeds a predetermined limit, the telephone communication system restricts the calling station from all further long distance transmission facility access and generates an alarm indication to identify a possible facility access problem.

Abstract: A personal memory card system is arranged for use with a memory card which looks and feels much like an ordinary credit card. No ohmic electrical contact is required between the card and a reader/writer in an associated station for transferring data to and from the card and operating power to the card. The need for conductive contacts in transferring data between the reader/writer and the card is avoided through use of a capacitive interface formed when insulated metallic plates on the card are aligned in close proximity with corresponding plates on the reader/writer. Operating power is transferred to the card through an inductive interface formed when a flexible flat inductor embedded in the card is aligned in close proximity to another inductor in the reader/writer. Data to and from the card and power to the card are reliably transferred even after some time of normal use since there are no exposed metallic surfaces to corrode or to which particles may collect.

Abstract: An automatic route selection capability for a communication system is described which enables the system to utilize digits of a called party number to select in a predetermined manner a predefined group of line pools and a line therein over which the call is to be placed. Once the predefined group of line pools is selected, a priority scheme enables the system to sequentially search each line pool for an available line over which the call can be placed. The system dials the called party using route character digits which prefix or optionally replace one or more of the user-dialed digits.

Abstract: A communication system includes station ports for connecting station sets to the system. A port circuit includes a number of conference registers which are not dedicated to particular station ports but rather are assigned as needed to port circuits. When a request is made to form an N party conference call, N-2 available ones of the conference registers are then assigned to each port of the port circuit which is involved in the resulting conference call connection.

Abstract: A power transfer arrangement provides regulated power transfer from a station to a contactless portable data card without the need for regulation circuitry on the card itself. The station includes a primary coil for magnetically coupling power to a secondary coil, located on the card, when the data card is brought into close association with the station. The arrangment includes a microprocessor, a power amplifier including the primary coil, a variable voltage source and apparatus for measuring current flow in the primary coil. When the portable data card is not in close association with the station, the microprocessor causes the variable voltage source to provide a sequence of stepped voltages. Quiescent current flow is measured at each step and stored in memory. When the portable data card is brought into close association with the station, the microprocessor causes the variable voltage source to provide a sequence of stepped voltages. Active current flow is measured at each step and stored in memory.

Abstract: A mounting bracket formed from a length of wire in a double-L configuration includes retaining clips which engage corresponding grooves formed in a modular cross-connect unit. The flexibility of the bracket's L-shape itself provides a spring function that holds the unit in the bracket when the grooves in the unit engage the retaining clips.

Abstract: A personal memory card the size of a standard plastic credit card is usable in a variety of applications, from custom repertory dialing to storage of individual medical and/or banking records. Although the card looks and feels much like an ordinary credit card, the personal memory card includes a computer, an electrically erasable field-programmable read-only memory and also circuitry for inductively receiving a power signal and capacitive transferring data signals between the card and a card reader/writer located in an associated station. No direct ohmic electrical contact is made between the card and the reader/writer for transferring power to the card or for transferring data to and from the card. The card is also reprogrammable by the associated station with new and different data as desired.

Abstract: Control equipment employed in a customer-owned public telephone station prevents a user from making unauthorized telephone calls in a telephone system. Operating under the control of a computer in the station, the control equipment employs a call screening process which restricts the telephone numbers a user can dial to those numbers preselected by a station owner. The telephone numbers are categorized in multiple but distinct groups, each of which represents a specific class of telephone call. The control equipment is responsive to momentary loop breaks occurring on tip and ring lines connecting the station to a central office, and to a loop break provided by the central office which reflects that the far end party has disconnected. The control equipment is also responsive to scheduled as well as unscheduled receipt of dial tone.

Abstract: This feature provides the telephone communication system with the capability to automatically select one of a plurality of inter-exchange carriers to serve an inter-exchange call originated by a telephone communication system user. In response to an inter-exchange call origination, the telephone communication system selects the appropriate and most economical inter-exchange carrier and then outpulses the inter-exchange carrier access code, the user's personal identification code and the called party number dialed by the user to complete the call.

Abstract: There is disclosed a call announcement circuit integrated into the switching network of a PBX switching system such that the announcement board resides in one of the port slots and has direct access to the internal system buses. The circuit can handle many separate announcements each stored at a selectable compression ratio. Each such announcement can be recorded or played in any of the time slots under processor control. This configuration allows tradeoffs between storage capacity and compression ratio (i.e., speech clarity) and also allows messages to be played on any line or to any station via the communication bus and the selected time slot.

Abstract: This invention relates to business communication systems and, in particular, to a message service system network that interconnects a plurality of message service systems and provides a voice mail message transfer capability between voice mail message service systems. The voice mail message transfer is performed as a computer-to-computer data file transfer operation over high speed data lines. The data file consists of the digitally encoded and compressed voice mail message to which is appended the message sender's name and telephone number as well as the message recipient's telephone number.

Abstract: A telephone stand has a housing with a cradle in its top for a handset adapted when placed in the cradle to depress a pair of laterally spaced plungers passing through holes in the housing down into its interior. A line switch is disposed in the housing below and laterally between the plungers. The plungers are coupled to the switch by a Y-shaped piston comprising a crosshead spanning the lateral spacing between the plungers, a pair of tines projecting upwards from laterally opposite ends of the crosshead and having vertical bores therein in which lower portions of the plungers are received, and a laterally central stem extending down from the crosshead and having camming surfaces thereon adapted upon downward displacement of the piston (by downward driving of either of both of the plungers) to wedgingly displace resilient blades in the switch to change switch conditions thereof.

Abstract: The subject implied principal busy status indicator provides all covering users with an indication of the busy/idle status of the principal's line on a covered call. This is accomplished by equipping each covering user's telephone station set with a principal busy status indicator for every line appearance on the covering user's telephone station set. When a covered call is diverted from a principal's line to the covering user's telephone station set, the line appearance on which the covered call appears is lighted and the principal busy status indicator associated with the covering user's line appearance indicates the busy/idle status of the principal's line. The business communication system updates the state of the principal busy status indicator so the covering user knows when the called principal's line is idle.

Abstract: A printing gap adjustment mechanism compensates for the change in the pring gap variation caused by the relative motion between two side walls of the printer frame supporting a platen and two guide rods slidably supporting a print head. The mechanism includes a compensator rod and a pair of eccentric members rotatably mounted in a compensator plate which is pivotally mounted on one side wall of the printer frame. One end of the compensator rod is frictionally secured to the opposite side wall while the other end is rotatably supported in an opening in the other side wall and is secured to an eccentric mounted to the compensator plate. One of the guide rods supporting the print head is located near the platen and is secured between two eccentric members, one of which is rotatably mounted in the compensator plate and the other is rotatably mounted in the opposite side wall. The other guide rod is secured between the two side walls.

Abstract: A call charge allocation arrangement is implemented for a business communication system to track those situations in which a toll call is transferred from a first station to a second station. The arrangement tracks such transfers by establishing a first call record at the time the call is placed and establishing a second call record at the time the call is transferred, such that call charges which accrue prior to the transfer are entered in the first call record and call charges which accrue subsequent to the transfer are entered in the second call record.

Abstract: The disclosed communication system enables communications between reconfigurable data terminals and a variety of connected computers, having dissimilar operating parameters, by automatically reconfiguring the operating parameters of the calling terminal to match those of the called computer. The system controller, in response to receiving the dialed number of the called computer from the calling terminal, accesses its memory for the operating parameters of the called computer and transmits these operating parameters to reconfigure the calling terminal. Another embodiment enables the operating parameters of a terminal to be reconfigured in any of a number of operating modes in response to a reconfiguration request signal sent to the system controller from the terminal.