Abstract: In a computer system employing a common bus that is shared by an initiator and a plurality of targets, there is provided a method and apparatus that prevents data stored in a buffer, when one of the targets temporarily suspends a data transfer with the initiator, from being overwritten, while simultaneously minimizing the number of interrupts that must be employed to effect the data transfer. According to the disclosed invention, the initiator is interrupted by a second target only after the transfer of data from the initiator to a first target has been temporarily suspended, and only after the second target has reselected the bus. After the second target has reselected the bus, data read from the second target and transferred to the initiator is stored in a synchronous stack in the initiator to prevent any data remaining in the buffer from being overwritten.

Abstract: A system for integrating a composite dielectric layer in an integrated circuit to facilitate fabrication of a high density multi-level interconnect with external contacts. The composite dielectric layer comprises of a polymer layer which normally comprises a polyimide that is deposited using conventional spin-deposit techniques to form a planarized surface for deposition of an inorganic layer typically comprising silicon dioxide or silicon nitride. The inorganic layer is etched using standard photoresist techniques to form an inorganic mask for etching the polymer layer. A previously deposited inorganic layer functions as an etch stop to allow long over etches to achieve full external contacts which, in turn, allows high density interconnect systems on multiple levels.

Abstract: A process is described for electrically interconnecting electronic devices located on a surface through one or more planar linking layers consisting of conductors and dielectrics. A three-step additive process is disclosed for forming each planar linking layer. The process may be repeated in order to form the multiple linking layers required for complex VLSI circuits. Each layer is formed by a three step process of applying a uniform dielectric, removing the dielectric where the interconnections, including vias and lines, are to be made and then selectively depositing a conductor to form the interconnections.

Abstract: A valve apparatus for controlling fluid flow comprising a substrate having a first aperture extending therethrough for defining a first fluid flow path; a beam having first and second terminal end portions mounted in fixed relationship with the substrate and having a bucklingly displaceable intermediate portion positioned in overlying relationship with the aperture for covering and uncovering the aperture for preventing or enabling fluid flow through the aperture; and a temperature control assembly for selectively controlling the temperature of the beam for selectively bucklingly displacing the intermediate portion of the beam for controlling fluid flow through the aperture.

Abstract: A sheet metal housing for an optical disk storage and handling apparatus which includes reference deformations provided in the sidewall panels of the sheet metal housing for locating mutually registerable components of the optical disk storage and handling system. A method of constructing such a sheet metal housing is also described.

Abstract: A method and system for forming tungsten structures in a semiconductor device which uses a chromium protective layer to protect underlying semiconductor layers during the etching process and a chromium mask layer so that tungsten structures can be formed with high aspect ratios using a reactive ion etching to etch the tungsten with a carbon tetrafluoride oxygen plasma in a reactive ion etcher. Long overetches can be achieved because of the high selectivity of chromium to the carbon tetrafluoride/oxygen plasma. The anisotropic nature of the reactive ion etcher prevents undercut during long overetches of the tungsten to further decrease losses in linewidth or increases in resistance as a result of overetching.

Abstract: A device and process for programmatically controlled in-circuit pin checks and gross functionality tests of digital to analog converters. The tests provide deterministic bit checks for higher order bits and non-deterministic or "delta" bit checks of low order bits independent of other circuitry on the printed circuit board of which the digital to analog converter is a component.

Abstract: A Class-A complementary metal oxide semi-conductor (CMOS) operational amplifier is provided having an improved slew rate. The preferred embodiment of the invention utilizes a CMOS amplifier circuit and an external capacitor, which together exhibit relatively poor sourcing of current and hence a relatively low positive slew rate in response to an input signal being more positive than an output signal of the CMOS amplifier by a relatively large amount. The disparity between the input and output signals defines an error signal. The present invention also includes a supplemental output stage communicating with the amplifier circuitry and the external capacitor. The supplemental output stage is activated in order to supply additional sourcing current, thereby increasing the positive slew rate, when a relatively large error signal is present and is de-activated otherwise.

Abstract: The trichromatic beamsplitter consists of composited dichroic beamsplitter plates that separate a projected image into its three color components with spatial as well as spectral precision. The three linear array photosensor comprises a monolithic sensor having three parallel photodiode arrays spaced precisely to accept the color component images of the trichromatic beamsplitter.The present invention also employs a spectral and spatial combiner that is capable of maintaining equal optical path lengths of each spectral beam so that a single combined beam can be produced and can be employed in a number of different applications such as a color camera device, a color recording device, a graphics presentation device, an electronic color filter device, a color projector device and a multi-channel optical communication device.

Abstract: A data compression system implementing expansion protection employs one or more pairs of FIFOs to compare the lengths of raw and processed versions of a block of received data. The shorter version is transmitted so that the data transmitted by the data compression system is at most negligibly expanded relative to the system input. A code is inserted in the output stream to indicate the beginning of the transmission of a raw data block so that a receiving or retrieving system can determine whether the data following needs to be decompressed or not. Further codes can be injected to indicate a switch from raw data to processed data in the output of the compression system.

Abstract: An algebraic recursion process is defined to solve test conditions for sequential and combinatorial logic devices. The process is shown to be effective in identifying external pin faults, and is valid for in-circuit test conditions. Since only external pin faults are considered, there is no issue of the correspondence of Boolean products to the internal architecture of the device. Processes to identify the fault detection equation and initialization sequence are described and an effective minimization process presented. Functions simple enough to be implemented by logic networks fall within a range which is computationally tractable by the process of the invention.

Abstract: An adaptive data compression system is reset when performance drops below a predetermined threshold to permit greater compression of long files with evolving distributions of symbol combinations. The compression system uses a resettable dictionary in which initially unassigned codes are strategically assigned to symbol combinations as they are encountered in the data stream.The difference between the bit-lengths of corresponding lengths of the compressor input and output is compared with a value representing a predetermined performance threshold. The dictionary can be reset if the actual performance falls below the performance threshold. The reset can be inhibited while the dictionary is less than half-full to ensure that performance measures are statistically significant. However, if the performance is such that data expansion is occurring, reset is not so delayed.

Abstract: Tape-automated-bonding (TAB) tape can be directly bonded (i.e., no "gold bumps" are needed) to aluminum bonding pads of integrated circuit devices, without contacting any other part of the integrated circuit device, by use of a process employing the herein disclosed parameters of ultrasonic energy, pressure, time, heat, and relative dimensions of the TAB tape.

Abstract: A board fixturing system is described for interfacing a printed circuit board having electronic devices at predetermined locations thereon to a probe plate having electrical contacts at predetermined locations. The fixturing system is mechanical and avoids the problems and limitations of the conventional vacuum fixturing systems. The fixturing system includes a unique conveyor system which is capable of staging one board while testing another, i.e. one board can be tested while another board is advanced toward the test fixture. A cassette system for the probe plates is also provided.

Abstract: A device for synchronizing the output test pattern signals of a test circuit with the clock signal of a device under test (DUT). The invention uses a programmable delay in the feedback loop of a phase locked loop system to adjust the phase of the test pattern signals to be synchronized with the clock of the device under test (DUT).

Abstract: The trichromatic beamsplitter consists of composited dichroic beamsplitter plates that separate a projected image into its three color components with spacial as well as spectral precision. The three linear array photosensor comprises a monolithic sensor having three parallel photodiode arrays spaced precisely to accept the color component images of the trichromatic beamsplitter.

Abstract: Small and/or large defects in dielectric materials can be detected by bombarding one surface of the dielectric material with gas ions in order to impart a charge on that surface while the opposite surface is under the influence of an opposite charge. The dielectric material is then exposed to an indicator substance having an affinity for the charge of the gas ions and a tendency to congregate on regions of the dielectric materials which contain defects.

Abstract: A solution to accurately aligning a read-write head over a previously written data track on both a write protected and not write protected tape is disclosed. A control unit, preferably a programmed microprocessor, electronically provides a sequence of control outputs to move the tape and step the head to locate an edge of the tape. The control unit then moves the head a fixed distance to be over a selected data track. A threshold circuit controls the readout of data from the head of the tape in such a way as to improve edge find reliability.

Abstract: An in-circuit test device and method for testing transistors which are connected to various components on a printed circuit board. The present invention uses a fully automated system which provides a constant emitter current to bias the transistor to a predetermined level and prevents the transistor from going into saturation due to variations in the gain of different transistors. The collector lead and base lead are maintained at approximately ground potential so that the collector emitter voltage drop is maintained above the saturation voltage for transistors since the base emitter junction is biased by a constant emitter current placed in the emitter lead. Transistor gain is determined from the difference in two separate d.c. emitter currents which eliminates the effects of parallel impedence paths resulting from other components connected to the transistor on the printed circuit board.