Abstract: A half-duplex digital speakerphone includes a control state machine which controls the selection of either a transmit or a receive audio path based upon a present state of the speakerphone and the magnitudes of three signal related variables associated with each path. The three variables for each path includes a signal power variable, a noise power variable and a worst-case echo variable. A change of state of the state machine results in the value of a variable gain within each of the paths being adjusted to optimize the transition time from the receive to the transmit state or from the transmit to the receive state. Also optimized is a change of state from an idle state to a transmit or receive state or from a transmit or receive state to the idle state. A change of state is accomplished in accordance with a smoothly varying, substantially Gaussian switching waveform which is selected to optimize the transition time between states while simultaneously minimizing audible side effects.

Abstract: A method and apparatus for detecting and analyzing errors in a communications system is described. The method employs expert system techniques to isolate failures to specific field replaceable units and attempts to restore the failing unit to service by removing it from service, resetting the resource and returning it to service if it passes retesting. The expert system techniques include detailed decision trees designed for each resource in the system. The decision trees also filter extraneous sources of errors from affecting the error analysis results.

Abstract: A method of etching in an O.sub.2 microwave plasma is provided which has a predetermined selectivity between a composite of two materials such as a photoresist and a polyimide is provided. The etch rate of each of the materials is measured at various temperatures and pressures, and this composite is then etched at a selected temperature and pressure which will provide the desired degree of selectivity.

Abstract: Apparatus for connecting data processing equipment to a communications network includes hardware for a range of different communications standards. Also included is a coupler (preferably in the form of a cable) having a particular standard communications plug which contains an identifying code associated with that particular standard plug, which code is used to configure the apparatus to that particular standard. The apparatus contains a digital signal processor controlled by control code contained in a control store having associated therewith a standard identifier code. Control logic reads the standard identifier code associated with the control code and the standard identifying code in the coupler and enables the apparatus if the two match (or disables if they do not match).

Abstract: The copy protection of personal computer (PC) software distributed on diskettes is assisted by providing a unique identification (ID) stored in read only memory (ROM) of a personal computer in which software on a diskette is to be used. This ID is accessible to the user of the computer. A vendor who wishes to protect his diskette-distributed software from illegal copying or use provides a source ID on the diskette. The personal computer ID is used with the source ID on the distributed diskette to produce an encoded check word, using any available encryption modality. The check word is generated and written onto the distributed diskette during installation and copied onto all backup versions made by the user's personal computer. Prior to each use of the program, the software on the diskette uses the personal computer and the source IDs and check word to verify that the software is being used on the same personal computer on which it was installed.

Abstract: A switching device on a printed circuit card assembly is provided which permits the signal ground of the printed circuit card to be grounded to the machine ground during insertion of the card into the frame of the machine, and when the card is fully inserted the switch is opened to allow the signal ground of the card to be electrically isolated from the machine ground of the frame.

Abstract: An improved method for forming shorting bars on ceramic capacitors of the tab type includes the step of effecting a final polishing of the tab exposed surface utilizing grit or abrasives of a critical size, namely of average particle size in the range of about 2 to about 10 microns. The method further employs thin film metallurgy namely the vacuum deposition or sputtering of one or more layers within specified thickness ranges. There is further disclosed an improved capacitor fabricated in accordance with the method described.

Abstract: A tamper-resistant package for protection of information stored in electronic circuitry includes apparatus for distributing electro-magnetic energy within a region occupied by the circuit to be protected. A sensing arrangement senses the distribution of the energy. In a preferred embodiment, electrical current is distributed through a coil or coils within which the circuit to be protected resides. The sensor includes an integrating circuit, and the output of the integrating circuit is presented to both a sample and hold circuit and to a comparator. The comparator has high and low reference input terminals which are fed from a voltage divider to which is also applied an output from the sample and hold circuit. The high and low reference inputs to the comparator are, by reason of the sample and hold circuit, adaptive. The comparator produces an output if its input is outside the limits established by the high and low reference inputs; that output of the comparator is taken as evidence of tampering.

Abstract: A pixel processor includes a plurality of pixel slice processors and the architecture is arranged so that the pixel length is extendible by merely increasing the number of pixel slice processors. Each of the pixel slice processors is firstly interconected with other pixel slice processors, and includes a plurality of registers, gates and multiplexers for selectively presenting to a processing means data derived from a variety of sources, including a frame buffer. The output of the processing means can be stored back in the frame buffer or directed to one or more registers in the associated pixel slice processor or/and to registers in other pixel slice processors. SIMD operation is accomplished for pixel lengths which are equal to or larger than the bit capacity of the pixel slice processors. In a particular embodiment of the invention, SIMD operation is effected on pixel lengths larger than the bit capacity of the pixel slice processors.

Abstract: Contaminant is removed from the interior of the holes in the vicinity of preselected locations by etching in a gaseous plasma wherein the sheath voltage is controlled in order to direct ions of the plasma to contact the interior of the holes in the vicinity of the preselected locations.

Abstract: In a semiconductor device, a contact with low resistance to a III-V compound semiconductor substrate was fabricated using refractory materials and small amounts of indium as the contact material. The contact material was formed by depositing Mo, Ge and W with small amounts of In onto doped GaAs wafers. The contact resistance less than 1.0 ohm millimeter was obtained after annealing at 800.degree. C. and the resistance did not increase after subsequent prolonged annealing at 400.degree. C.

Abstract: A method is disclosed for controlling the monitoring of telephone status changes by an associated processor. A status change inquiry message is transmitted from the associated processor to the telephone and is utilized to set an interrupt mode within the telephone. The status change inquiry message may also include a timer setting value which is utilized, in a preferred embodiment of the present invention, to determine a maximum duration for the interrupt mode. In response to a change in telephone status, or the termination of the timed interrupt mode, a single phone status message is sent to the associated processor and the interrupt mode is terminated. In this manner, a change in phone status may be determined by the associated processor without the necessity of continuously polling the telephone. Further, any transmission of a phone status change terminates the interrupt mode and prohibits the telephone from continuously interrupting the associated processor with status change messages.

Abstract: Polyimide is etched by contacting the polyimide with an aqueous solution of a metal hydroxide followed by contact with an acid followed by contact with an aqueous solution of a metal hydroxide. Etching of chemically cured polyimide can be enhanced by employing a presoaking in hot water. Also, partially etched chemically cured polyimide is removed with a concentrated acid solution.In preparing a metal coated polyimide structure for subsequent gold plating, two flash etching steps with the polyimide etch between are employed after developing the photoresist.

Abstract: A character generator with multidirectional scan and variable line and character (or symbol) size capability. Universality is implemented by producing a serial binary stram which can be used to print or display in any of eight combinations of scan direction and progression, that is, for scan direction left to right, or vice versa, progressing up or down, or scan direction top to bottom or vice versa, progressing left or right. In formatting the serial binary stream, a font is accessed (for basic symbol definition), which selectively provides for orthogonal scans of the symbol definitions. Variable line size is implemented by terminating a symbol row (or line) based on a predetermined size criteria regardless of the comparable font dimension and "filling" up to the line size to the extent the corresponding font dimension is less than the predetermined size criteria.

Abstract: A word processing system in which text can be displayed on a display device and audio recording and playback means is provided to permit a user to record an audio message includes means for monitoring the volume level of speaking by the user and means for notifying the user if the volume level of the speaking by the user is too high or too low. Also, the system allows the user to pause and resume during recording and playback without requiring re-recording or re-playback of the entire message.

Abstract: A method of forming successive metal layers of varying widths on a substrate is disclosed. A mask having a through going aperture is provided, the mask including a constricted neck portion between its upper and lower surfaces. Successive metal layers are applied over the substrate through the aperture in the mask sequentially by sputtering methods which form a metallic layer wider than the constricted neck portion of the mask and by vapor deposition method which forms a narrower metal layer corresponding to the transverse dimension of the constricted portion of the mask.

Abstract: A color graphic processor includes one or more processing elements responsive to pixel data provided by a frame buffer. The processing element stores pixels from the frame buffer in source and destination registers. The arithmetic logic unit (ALU) portion of the processing element includes a random access memory (RAM) addressed by the registers to produce a result pixel value which can be written back to the frame buffer. The RAM can implement a wide variety of pixel operations by loading the RAM with operation specific data.

Abstract: An array of thin film transistor (TFT) devices is provided with a conductive region, such as a strip, for temporarily coupling a floating pel eletrode of each of the plurality of TFT devices to a conductor on an underlying substrate. The conductor may be a row or column metalization line associated with an adjacent row or column of the array. The conductive strip may therefore be utilized, in conjunction with appropriate voltage potentials and test circuitry, to test each of the TFT devices prior to the final fabrication of the TFT array into a completed flat panel display. Thus, nonfunctioning or out of specification arrays may be identified at an early point in the manufacturing cycle of the display. The strip may be comprised of amorphous silicon which is illuminated during the test in order to reduce the intrinsic resistance of the strip. The strip may also be comprised of a layer of metalization, which layer is removed from the array at the completion of the test.

Abstract: A method of operating a data processing system using virtual memory in which virtual memory addresses are formed by a base register value and a displacement value and are mapped to real memory addresses includes the steps of adding the base register value content and the displacement value, and simultaneously with the adding operation, performing a translation of the base register value to produce a virtual address corresponding to the base register value.

Abstract: To encode hierarchial information the invention recognizes that there is implicit information which must be made explicit. Thus the hierarchial information is annotated by selectively adding to it two spatial representing characters, each instance of a first spatial representing character corresponds to a unit step to the right, each instance of a second spatial representing character represents a unit identation to the left, and the first instance of the second spatial representing character in a string of the second spatial representing characters also represents a carriage return and line feed. The annotated hierarchial information is then scanned to produce two byproduct strings. The first byproduct string is merely the sequence of first and second spatial representing characters, in the order in which they appear, to which is added two place holding characters, one representing an alpha-numeric string, and the second representing a string of one or more blank or null characters.