Abstract: An apparatus provides for recovery from a loss of synchronization in a queued data transfer between a controller and a peripheral device. The apparatus eliminates the need for a timeout mechanism within the controller. A method of operating the apparatus provides proper sequencing following a loss of synchronization as well as the correct status report for the data transfer which immediately preceded the loss of synchronization.

Abstract: A mold for the formation of plastic Luer nuts having a polygonal internal cross-section. The mold includes both movable and fixed cavity sections, so that a non-round threaded core can be unscrewed from within the Luer nut.

Abstract: A modification of a woven cable (wire and fabric woven together to form a flat ribbon cable) assembly, in which the signal wires of the transmission lines are replaced with solderable resistance wires, thereby providing an economical method of building multiple lossy transmission lines.

Abstract: An access door is described for a housing for tape drive apparatus of the type including a take-up reel, a hub for a supply reel, and a fan for moving air within the housing. The access door is hinged to the housing and is pivotable between open and closed positions. The access door includes an interior face which forms a ramp for guiding the supply reel into the housing and onto the hub. The door also includes an inlet port for receiving air from the fan, at least one exit port, and a passageway for communicating air between the inlet port and the exit port. Air leaving the exit port in the door is directed around the periphery of the supply reel.

Abstract: A hybrid hardware/software implementation of a translation look-aside buffer (TLB) is provided which improves the efficiency of address translation in a computing system utilizing a virtually addressed memory. To access a physical memory location a processor first attempts to fetch a virtual-to-physical address translation from a primary TLB. If the address translation is not in the primary TLB, the processor attempts to fetch the address translation from a secondary TLB. If the address translation is not in the secondary TLB, a trap is generated, after which the processor searches a virtual address translation table for the address translation. Through the use of the present invention, complex hashing routines can be used to address entries in a virtual address translation table (VATT) within the system's physical memory, without increasing the complexity or significantly reducing the performance of the TLB fetch hardware.

Abstract: A high efficiency non-dissipative snubber circuit suitable for most power supplies used in international markets is disclosed. Circuit uses diode-capacitor-inductor structure to capture input voltage equivalent and reverse polarity on snubber capacitor. No external voltage source is required.

Abstract: Block pattern detection circuitry for the read subsystem of a streaming tape drive system comprises a state machine, a pattern decoder, a tape mark detector, a block/gap filter, a block/gap meter, a verify count section, and a block read/verify section. The incorporation of a hardware state machine within the block detect circuitry permits the application of historical detect data in the interpretation of present detect data. This provides more certain pattern recognitions. Also, state data is fed back to the block/gap filter allowing precise block boundary triggers which are used by position capture circuitry and the drive controller to effect more precise re-try positioning. The use of the block/gap filter increases the detect circuitry's immunity to noise. The advantage is enhanced where the block/gap filter uses stochastic thresholding, which is also advantageously employed by the tape mark detector.

Abstract: A tape drive system employs position capture circuitry to facilitate accurate positioning of the tape media. The position capture circuitry includes an input polling state machine (101) to ensure each detection results in exactly one position value transfer. A timing section (103) synchronizes the polling of inputs with data transfers. A bus multiplexing section (105) provides for 12-bit resolution over 8-bit busses. The position types can be data block boundaries or reel-encoder marks or position requests by the servo controller. The input lines (41-44) are polled routinely, ensuring that the stored values precisely reflect the referenced positions.

Abstract: Techniques are described for securing a magnetic head to a support carrier for the head in a magnetic storage device (e.g., a tape drive apparatus or disk drive apparatus). One such technique involves temporarily supporting a magnetic head on a fixture which is adapted to cooperate with openings on the magnetic head to orient the head in a predetermined alignment attitude so that the head may be permanently mounted in the magnetic storage device. In another embodiment the fixture may be part of the magnetic storage device itself. There are also provided various embodiments of magnetic heads having openings for accessing a planar interface between the halves of a magnetic core within the head. By accessing this interface the magnetic head may be aligned in a predetermined alignment attitude.

Abstract: An adaptive rewind system is described for use in tape drive apparatus or other apparatus involving roll goods which are movable between a supply reel and a take-up reel. The system includes (1) comparison means for (a) comparing the voltage at the motor driving the supply reel to a supply reference voltage, and (b) comparing the voltage at the motor driving the take-up reel to the supply reference voltage, and (2) control means adapted to maximize the velocity of the roll goods while being wound from one reel to the other. The control means is adapted to drive at least one of the motors with a voltage essentially equal to the supply reference voltage, while the voltage at the other motor does not exceed the supply reference voltage.

Abstract: A supply reel hub for use on a computer tape drive for assuring that a supply reel is squarely locked down and properly aligned on the computer tape drive. The supply hub comprises a locking means in the form of three L-shaped feet for locking the supply reel securely in place, a plurality of spaced apart sensing means and a plurality of signalling means which sense and signal to a controller whether each of the three L-shaped feet of the locking means are properly in position. A centering knob positioned on the top of the supply hub has been provided so that a supply reel may be easily centered over the supply hub. A groove is positioned on the base of the supply hub to allow a write enable tab to slip off of the supply hub and not hang up on the centering knob. Additional sensing means are provided for sensing whether there is a write enable ring on the supply reel. Means for releasably attaching the shaft of the drive motor to the hub base which reduces tape edge damage is also provided.

Abstract: A heated transfer line for heating a small glass capillary tube is disclosed. The transfer line is small and removable yet highly efficient, capable of uniformly heating a glass capillary tube over a 5-inch length to more than 400 degrees with less than 30 watts of power. The power is applied to an electrically conductive heater tube, which encircles the glass capillary, via first and second current conductors attached to respective ends of the heater tube. The first and second current conductors are arranged in proximity to the heater tube and back along the heater tube to a common point without touching each other. Electrical insulation is disposed between the heater tube and the first and second current conductors to electrically isolate the heater tube from the current conductors. A cover of thermal insulation is disposed over the heater tube and the current conductors and is used to thermally isolate the heater tube. An outer tube is disposed around the thermal insulation as a cover.

Abstract: A heated transfer line for heating a small glass capillary tube is disclosed. The transfer line is small and removable yet highly efficient, capable of uniformly heating a glass capillary tube over a 5-inch length to more than 400 degrees with less than 30 watts of power. The power is applied to an electrically conductive heater tube, which encircles the glass capillary, via first and second current conductors attached to respective ends of the heater tube. The first and second current conductors are arranged in proximity to the heater tube and back along the heater tube to a common point without touching each other. Electrical insulation is disposed between the heater tube and the first and second current conductors to electrically isolate the heater tube from the current conductors. A cover of thermal insulation is disposed over the heater tube and the current conductors and is used to thermally isolate the heater tube. An outer tube is disposed around the thermal insulation as a cover.

Abstract: Provided is a cache memory architecture which is two blocks wide and is made up of a map RAM, two cache data RAMs (each one word wide), and a selection system for selecting data from either one or both cache data RAMs, depending on whether the access is between cache and CPU, or between cache and main memory. The data stored in the two cache data RAMs has a particular address configuration. It consists of having data with even addresses of even pages and odd addresses of odd pages stored in one cache data RAM, with odd addresses and even addresses interleaved therein; and odd addresses of even pages and even addresses of odd pages stored in the other cache data RAM, with the odd addresses and even addresses interleaved but inverted relative to the other cache data RAM.

Abstract: A wide bandwidth R. F. vector bridge is provided which is made up of a housing and a microcircuit contained therein. The microcircuit includes a substrate having two opposing faces, and a patterned layer of conductive material on each face defining a reflection port area, a reference port area, and a test port area. A first impedance means provides a first impedance between the reflection port area and the reference port area, and a second impedance means provides a second impedance between the reflection port area and the test port area. Also included are a reflection port means for coupling the reflection port area to other electrical components, a reference port means for coupling the reference port area to a reference load, and a test port means for coupling the test port area to a device under test.

Abstract: A resonant mode energy recovery circuit is disclosed for supplying drive pulses to an electroluminescent (EL) display arranged as a matrix of pixels addressed by a plurality of column and row electrodes. An external inductor is used to alternately store and supply energy from the column electrodes of the EL display which has an impedance equivalent to an array of capacitors and resistors. Switching transistors and diodes are used to start and stop the resonant current flow at 1/4 wavelength intervals of the resonant frequency of the resonant tank formed by the external inductor and the array capacitors coupled to the column electrodes in order to form the pulses required to address the columns of the matrix. Switched current sources are used to start and stop nonresonant current flow to form the refresh and write pulses used to form the pulses required to address the rows of the matrix.

Abstract: An automated cassette handler for transporting a cassette containing integrated circuit wafers between first and second elevators in a standardized mechanical interface (SMIF) system for integrated circuit processing. The handler is adapted to grip and transport the cassette while positively pushing the wafers into the cassette.

Abstract: A precision vector network analyzer which is suitable for a wide range of applications including both laboratory and automated production measurements and testing is disclosed. New measurement capabilities, greater ease of use, and nearly complete automation are provided. Contributions include fully coordinated communications between subsystem modules; real time, two channel, precision vector measurements with complete, internal error correction; wide frequency capability from RF to millimeter bands; combined time and frequency domain analysis and display; measurements either in the swept or step frequency modes; and user definable test functions and calibration device sets.

Abstract: A precision vector network analyzer which is suitable for a wide range of applications including both laboratory and automated production measurements and testing is disclosed. New measurement capabilities, greater ease of use, and nearly complete automation are provided. Contributions include fully coordinated communications between subsystem modules; real time, two channel, precision vector measurements with complete, internal error correction; wide frequency capability from RF to millimeter bands; combined time and frequency domain analysis and display; measurements either in the swept or step frequency modes; and user definable test functions and calibration device sets.

Abstract: A new phenomenon in integrated circuit etch processing is presented, explained and utilized to permit better removal of layers overlying integrated circuit structures, and if desired, the formation of conductive layers on such structures by a less complicated and lower temperature process than has been possible by conventional techniques.