Abstract: A mechanized system distributing the access, test and communication functions to the point of testing, typically the centralized switching facility serving the telephone loops and equipment to be tested. Computer (200) stores information about each subscriber loop in the geographical area served by a system. Front-end computers (200,201) interact with computer (200) to retrieve pertinent data regarding loops to be tested. Each switching facility in an area includes a loop testing system (e.g., 160) that implements the required functions. The communication functions residing in front-end computers (220,221) and loop testing systems (160,161) are coupled via a data communication network (140) in a manner that allows any front-end computer to communicate with any loop testing system. Users of the system control access and test from consoles having the capability of establishing independent communication paths over the national dial network for interactive tests on loops accessed through standard test trunks.

Abstract: A mechanized system distributing the access, test and communication functions to the point of testing, typically the centralized switching facility serving the telephone loops and equipment to be tested. Computer (200) stores information about each subscriber loop in the geographical area served by a system. Front-end computers (220,221) interact with computer (200) to retrieve pertinent data regarding loops to be tested. Each switching facility in an area includes a loop testing system (e.g., 160) that implements the required functions. The communication functions residing in front-end computers (220,221) and loop testing systems (160,161) are coupled via a data communication network (140) in a manner that allows any front-end computer to communicate with any loop testing system. Users of the system control access and test from consoles having the capability of establishing independent communication paths over the national dial network for interactive tests on loops accessed through standard test trunks.

Abstract: A connecting block for a digital cross connect system has printed wiring circuit boards to interconnect terminals on the rear surface with jacks and terminals on the front surface. The terminals on the front surface are multipled to jack appearances also on the front surface of the connecting block. The connecting block has a pedestal which sits on a lower crossarm of a frame. The upper surface of the connecting block has a resilient tang which snaps into an upper crossarm of the frame. The tang is depressed with a screw driver or the like to disengage it from the upper crossarm. The connecting block is suspended by the anterior section of the pedestal from a panel located in front of the lower crossarm to expose the terminals on the rear surface. Conductors in cables to and from digital systems are then terminated on the rear terminals.

Abstract: A single substrate with a stripline circuit on one of its surfaces for use in a down converting mixer has a thin metallic film deposited utilizing photolithographic techniques onto two free ends: one end with the junction section of the stripline circuit for establishing a ground path with the metal block upon which the substrate rests and the other end with the filter section of the stripline circuit for establishing the intermediate frequency signal path with the inner conductor of a coaxial cable.

Abstract: A method for dynamically altering Read-Only Memory (ROM)-based programs utilizes Random-Access Memory (RAM) and standard processor linkages associated with subroutine or function calls. Each original ROM program includes a statement to call a ROM processing routine. If information passed to the processing routine by the original routine indicates a RAM-based replacement routine is to be executed for the original routine, the processing routine (i) restores the processor to its state immediately following the call to the processing routine, and (ii) branches directly to the replacement routine at a location provided by a RAM-based data structure.

Abstract: A mechanized system distributing the access, test and communication functions to the point of testing, typically the centralized switching facility serving the telephone loops and equipment to be tested. Computer (200) stores information about each subscriber loop in the geographical area served by a system. Front-end computers (220,221) interact with computer (200) to retrieve pertinent data regarding loops to be tested. Each switching facility in an area includes a loop testing system (e.g., 160) that implements the required functions. The communication functions residing in front-end computers (220,221) and loop testing systems (160,161) are coupled via a data communication network (140) in a manner that allows any front-end computer to communicate with any loop testing system. Users of the system control access and test from consoles having the capability of establishing independent communication paths over the national dial network for interactive tests on loops accessed through standard test trunks.

Abstract: A computer architecture is disclosed which obtains the advantages of stack oriented machines from a programming viewpoint and, at the same time, obtains the hardware advantages of a multiple operand architecture from the hardware viewpoint. This is accomplished by circuitry (13) which accepts stack oriented reverse-polish instruction tokens from the memory (10) and, by using a lookahead technique (23), optimizes the generation of storage-to-storage type instructions which are then executed by the storage-to-storage hardware configuration (14).

Abstract: Fair and fast service to a plurality of channels served by packet switches at nodes interconnected through a common carrier facility is achieved by controlling the quantity of data sent from any one channel to another. When data arrives at a node from a channel, the channel address is entered in line in the first of two channel address queues and the data is entered in a separate data queue. Each channel address is read from the first queue, a predetermined number of data bytes is read from the corresponding data queue and sent in a frame to a distant node. Thereafter, the channel address is entered at the end of the second, lower priority queue. The frame may have data bytes from other first queue channels but the frame length is limited either by a predetermined number of bytes or when no more channel addresses remain in the first queue. When no channel addresses remain in the first queue, a new frame is started by reading a channel address from the lower priority second queue.

Abstract: A stream of binary bits is converted into blocks of eight parallel bits. A first group of five of the eight bits addresses a memory device which has thirty-two code words each having four numbers representing the coordinates of signal points in four-dimensional space. The remaining three of the eight bits are expanded to four bits by a convolutional encoder having three bits of memory. These four bits are then used to multiply the four numbers of a code word read out from the memory device. This method permits a block of eight binary bits to be coded into any one of five hundred and twelve four-dimensional code words.

Abstract: A distortion simulating pilot is injected at the input of an amplifier which uses feed forward distortion correction. The magnitude of the pilot signal in the amplifier output is used to control a decreasing step size circuit algorithm for adjusting the gain and phase of the feed forward distortion signal to eliminate substantially the pilot signal and the distortion introduced by the amplifier.

Abstract: A methodology for decomposing a three-wire equivalent circuit into a cascade arrangement of a two-wire transmission line and a three-port terminating network is disclosed. Decomposition synthesis is accomplished by iteratively separating the equivalent circuit into the two component parts according to a predetermined algorithm and then comparing the derived three-port network to each network within a class requiring identification, thereby effecting an identification whenever a match occurs. Upon a matched condition, the resistance of the transmission line corresponds to the distance to the terminating network and may be used for fault diagnosis purposes.

Abstract: In laying out integrated circuits on a substrate, the placement of the components relative to each other is important in minimizing conductor area and hence chip area. Large scale integration often uses polycells which are lined up in rows to realize the digital logic circuitry. A partitioning procedure is disclosed which iteratively separates the cells into maximally connected subcells, eventually to assign them to rows so as to minimize conductor area. A technique called terminal propagation takes into account at every iteration the location of connections outside of the partitioned area. Rectilinear Steiner trees are generated to aid in terminal propagation.

Abstract: A programmable digital controller has an address matrix memory (20) and an instruction matrix memory (10). The address memory stores address words each having the address of the first sample and the number of samples in a unique group of samples. Unique groups of samples are sequentially stored in an instruction matrix memory. Each column of the instruction memory has data bits for regenerating an instruction set for controlling any one of many apparatus or processes. Each row of the instruction memory has a sample from each instruction set. In response to an enabling signal, the words from the address memory are sequentially read, interpreted, and the samples from the instruction memory caused to be read and for reconstructing the instruction set.

Abstract: A mechanized system distributing the access, test and communication functions to the pont of testing, typically the centralized switching facility serving the telephone loops and equipment to be tested. Computer (200) stores information about each subscriber loop in the geographical area served by a system. Front-end computers (220,221) interact with computer (200) to retrieve pertinent data regarding loops to be tested. Each switching facility in an area includes a loop testing system (e.g., 160) that implements the required functions. The communication functions residing in front-end computers (220,221) and loop testing systems (160,161) are coupled via a data communication network (140) in a manner that allows any front-end computer to communicate with any loop testing system. Users of the system control access and test from consoles having the capability of establishing independent communication paths over the national dial network for interactive tests in loops accessed through standard test trunks.

Abstract: A graphic terminal is disclosed using bitmaps to represent plural overlapping displays. Graphics software is also disclosed in which the overlapping asynchronous windows or layers are manipulated by manipulating the bitmaps. With this software, the physical screen becomes several logical screens (layers) all running simultaneously, any one of which may be interacted with at any time.

Abstract: An interactive information retrieval system is disclosed in which a large number of user terminals interact bilaterally with a centralized computer controlled data base by using a communications controller. In order to speed up the response time of the system, long messages from the controller to the terminal are broken into two segments, one segment just sufficiently long to engage the attention of the user while the balance of the message is being transmitted and verified. The balance of the long message is contained in a second segment. This process and apparatus may be implemented by hard-wired circuitry or by a programmed computer.

Abstract: A mechanized system distributing the access, test and communication functions to the point of testing, typically the centralized switching facility serving the telephone loops and equipment to be tested. Computer (200) stores information about each subscriber loop in the geographical area served by a system. Front-end computers (220,221) interact with computer (200) to retrieve pertinent data regarding loops to be tested. Each switching facility in an area includes a loop testing system (e.g., 160) that implements the required functions. The communication functions residing in front-end computers (220,221) and loop testing systems (160,161) are coupled via a data communication network (140) in a manner that allows any front-end computer to communicate with any loop testing system. Users of the system control access and test from consoles having the capability of establishing independent communication paths over the national dial network for interactive tests on loops accessed through standard test trunks.

Abstract: Pattern-matching circuitry is shown which permits the simultaneous or near simultaneous matching of entire lines of text to a regular expression test pattern. A synchronous or clocked embodiment is disclosed, as well as an asynchronous embodiment.

Abstract: A fractionally spaced adaptive equalizer is disclosed wherein the coefficients (C.sub.-2 to C.sub.+2) are updated synchronously by an integral -T error circuit (40) and alternately by a fractional =T error circuit (48). This arrangement features a single unique minimum for the adaptive structure thereby preventing the coefficient drift to very large values so coefficient tap leakage is not required to minimize coefficient values. The adaptive characteristic is well suited for linearly dispersive channels, such as exhibited during terrestrial radio transmission during tropospheric multipath propagation. The inventive principles are broadly applicable to any of the well known algorithms for adapting digital filters. A configuration of fractionally spaced equalizers (70.sub.1 -70.sub.4) provides the benefits of Nyquist-rate coefficient updating for a dual rail quadrature amplitude modulated (QAM) signal application.

Abstract: A split-barrel connector terminal is presented wherein a wire connected to the terminal is released as a new wire is being connected. This feature is provided by aperture (13) located a predetermined distance from the wire receiving end of slot (12). When insertion tool (51) forces wire (61) into slot (12), wire (52) is pushed into aperture (13) terminating its mechanical and electrical connection to terminal (11). Terminal (11) has locking shoulders (17) and (18) which permit insertion of the terminal into insulation sheet (32) but prevent removal of the terminal. Sheet (32) and sheet (33) are molded pieces which fit together to provide insulating housing structures for terminal (11). Slot (43) in the housing secures the wires connected to terminals (11) and provides a strain relief function. This arrangement reduces the number of parts making an otherwise complex assembly easily and economically manufacturable.