Abstract: This invention is an interface arrangement which interconnects a business communication system with a telephone station set. This interface is implemented in a personal computer which serves to control the operation of the associated telephone station set and also provide business communication services. All signaling from the business communication system is received by the personal computer, interpreted, and appropriate control signals are then forwarded under control of the software resident on the personal computer to activate the digital telephone station set. The signals from the digital telephone station set are intercepted by the personal computer, interpreted, modified and appropriate control messages and signaling are then forwarded by the personal computer to the business communication system.This arrangement enables a user to create software on the personal computer to control the operation of the telephone station set associated with the personal computer.

Abstract: The UNIX.RTM. and MS-DOS.RTM. operating systems are supported in a multi-tasking computer. At the heart of the computer is a microprocessor having protected and non-protected modes. The computer includes special-purpose hardware which prevents the MS-DOS system and its applications, which execute in the non-protected mode, from interfering with the UNIX system and its applications, which execute in the protected mode. In particular, this hardware monitors addresses generated by the computer and, by selectively inhibiting the associated control pulses, prevents the MS-DOS system from, for example, writing in UNIX-system-allocated memory, or accessing I/O devices that the UNIX system is currently using. In addition, a context switching feature is provided whereby the user can select, via a keyboard operation, to have displayed on the computer video monitor at any given time the image generated from the current UNIX system screen data or the image generated from the current MS-DOS system screen data.

Abstract: The UNIX.RTM. and $MS-DOS sup R $ operating systems are supported in a multi-tasking computer. At the heart of the computer is a microprocessor having protected and non-protected modes. The computer includes special-purpose hardware which prevents the MS-DOS system and its applications, which execute in the non-protected mode, from interfering with the UNIX system and its applications, which execute in the protected mode. In particular, this hardware monitors addresses generated by the computer and, by selectively inhibiting the associated control pulses, prevents the MS-DOS system from, for example, writing in UNIX-system-allocated memory, or accessing I/O devices that the UNIX system is currently using. In addition, a context switching feature is provided whereby the user can select, via a keyboard operation, to have displayed on the computer video monitor at any given time the image generated from the current UNIX system screen data or the image generated from the current MS-DOS system screen data.

Abstract: This message chronicling apparatus consists of a personal computer interposed between the principal's telephone station set and the port circuit of the business communication system which serves the principal's telephone station set. The personal computer intercepts all call signaling from the business communication system. The personal computer software collects the data so received and creates a record in the memory of the personal computer of the incoming call. The principal's personal computer not only interacts closely with the business communication system, but can also be interconnected in a local area network with other personal computers or terminal devices such that a user at one of the other devices or personal computers can create a call record for the principal's personal computer.

Abstract: An overhead optical scanner is disclosed which uses commerical 60 Hz AC powered fluorescent lighting apparatus to illuminate the scanned objects. The image sensor of the scanner operates at a line scan rate which is in sync with the 60 Hz rate. The image sensor integrates the variations in illumination intensity received from the object over one complete 60 Hz cycle, thereby producing an electrical signal which is characteristic of a uniformly illuminated object.

Abstract: There is disclosed an asynchronous pulse catching circuit that, for each edge of the variable frequency input, regardless of duty cycle, will provide a pulse, synchronized to a high speed clock. There is also disclosed a pulse comparison circuit consisting of a state machine that provides slip detection between the variable input frequency and a reference input frequency. The circuit provides separate outputs indicating positive and negative slip.

Abstract: A timing control arrangement that dynamically controls the distribution of iming information in a distributed digital communication system. A reference timing signal is distributed from a reference master node to all other nodes in the system. The distribution is accomplished on a dynamic basis without the use of a central control. Each node is connected by links to at least one other node and each node receives timing signals from all of the links to which it is connected. Each node selects one of these signals as its timing reference by scanning the various signals it receives to identify the one signal that is applied via a link path that is the "closest" to the master reference node as indicated by information specifying the number of intermediate nodes through which the timing signal has traveled from the reference node to reach the receiving node.

Abstract: An interface unit connected to one end of a communication path is arranged to conduct a transmission test of the path before exchanging information with an interface unit connected to the other end of the path and to signal the results of the test by terminating the test when the results show an absence of transmission errors and continuing the test when the results show the presence of such errors, the test being the transmission and reception of a predefined sequence of signals.

Abstract: This is an improved resistive line battery feed circuit where the improvement consists in establishing a balanced stable power point using an opamp and capacitive input and feeding the AC output to both lines of the tip and ring circuit via opamps and a hybrid for injecting current. In this manner longitudinal balance is maintained. Current is added to the line circuit by a modulated DC current source.

Abstract: A system has been devised that allows commonly used software components to be designed and developed only once, and reused many times in different applications with different operational contexts and requirements. The system includes a language for the specification of software components in a context-independent generic fashion, a compiler for the specification language and a program for generating concrete software components to work in a specific context.

Abstract: The integrated calling directory of the present invention eliminates the disadvantages of prior call directory arrangements by providing a software system which runs on a personal computer to automate the call directory and call origination function. The personal computer is interposed between an individual's telephone station set and the business communication system port circuit associated with the individual's telephone station set. The calling directory software both contains the individual's personal directory entries and has access to directory entries in the centralized business communication system data base which resides on an adjunct processor. These directory entries all contain called party identification data which includes information such as an individual's name, room number, electronic mail address, telephone number, type of terminal equipment associated with the called party, job title, etc.

Abstract: A communication system is comprised of two or more circuit pack modules mounted onto a mounting apparatus. Each circuit module includes a plastic housing which holds a circuit board mounted therein. An equipment cabinet is formed by mounting a circuit module at each end of the mounting apparatus and utilizing a surface of each circuit module, respectively, as a side of the cabinet. A top panel of the cabinet mounts to the mounting apparatus and circuit modules and covers the circuit modules and any space therebetween. A front panel mounts to the top panel and circuit modules and serves as the front cover of the cabinet.

Abstract: A computer-controlled cordless telephone system having a base unit and a dset unit provides for increased functionality in communications between the base unit and the handset unit, and also provides a controlled power-up/power-down mode of operation for the handset unit. Increased functionality is achieved by employing a message format for control signals transmitted between the base unit and the handset unit in the form of frequency shift keyed (FSK) signals which include a data field. This data field may be in the form of either opcode data or digit data, thereby allowing for many different commands or functions. Power to a computer, a receiver and certain other selected circuitry in the handset unit is controlled to minimize power consumption when the handset unit is in an out-of-cradle-and-standby state. Power to other nonessential circuitry in the handset unit is turned completely off during this state.

Abstract: This invention provides an audible indication to a held party indicating when a call is removed from the hold state. Heretofore, when two parties on a call are in a talk state and a first party puts a second party on hold, the held party must aurally monitor the receiver on the station set for the first party's voice to detect when the talk state is resumed. The voice of the first party provides the only indication that the hold condition has been removed. This requires the held party to monitor the receiver for the duration of the hold state and prevents the held party from easily pursuing any other activities. The subject arrangement overcomes this problem by providing a "ring-ping" signal to the held party when the hold condition is removed. In particular, following the activation of the hold condition by the first party, the held party leaves the receiver off-hook and can then pursue other activities.

Abstract: Apparatus for and a method of inserting circuit switch information and packetized data into different time slots of a time division multiplexed bus. A memory having a location individual to each time slot is written with information specifying whether the time slot individual to each location is to serve circuit switch information or packet data. The readout of each memory location during the occurrence of it's associated time slot controllably effects the application of either the circuit switch information or the packet data to the bus. Packet data can be inserted into each time slot not currently being used by the circuit switch. A special information bit is inserted into each time slot to specify whether the remainder of the bits of the time slot represents circuit switch or packet information. The information bit is used by receiving apparatus to steer the bits of each time slot to either a receiving circuit switch or a receiving packet switch.