Patents Represented by Attorney, Agent or Law Firm Barry N. Young
  • Patent number: 5230044
    Abstract: An improved arbitration technique for a computer network system in which multiple nodes communicate using a shared bus. Each node in the system is assigned an initial arbitration number, N+1, where N is the node number assigned to the node. The arbitration number is the number of quiet slots a node must count before trying to transmit on the system bus. The length of a quiet slot is determined by a particular system's electrical characteristics. Each node in the system monitors a carrier signal on the system bus, the presence of which indicates that a node is transmitting on the bus. Upon detecting the absence of the carrier signal, each node in the system begins to count quiet slots. Every time a node counts an additional quiet slot, it checks to see if the count matches its arbitration number. If the two values are equal, the node checks to see if it has a transmit request, and begins to transmit a message on the system bus if a transmit request is present.
    Type: Grant
    Filed: July 2, 1990
    Date of Patent: July 20, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Xi-Ren Cao, Mohammad V. Abidi, Nii Quaynor, Fernando Colon-Osorio
  • Patent number: 5228083
    Abstract: A device and related method for cryptographically processing data packets being forwarded in both directions between a communication network and a client interface, using only a single cryptographic engine, but without any degradation in latency or throughput performance, as compared with a device using two cryptographic engines Outbound data packets received from the client interface are immediately parsed to determine if cryptographic processing is required, and an appropriate portion of each packet may be cryptographically processed as the packet is received and stored in an outbound buffer memory, until forwarded onto the communication network. Inbound data packets received from the communication network are not immediately parsed but are stored in an inbound buffer memory until the client interface is available.
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: July 13, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Philip P. Lozowick, Siman-Tov Ben-Michael
  • Patent number: 5226966
    Abstract: An apparatus for providing radial uniaxial anisotropy in the soft magnetic layer of a magnetic recording disk is disclosed. While the soft magnetic layer is being deposited on the recording disk, the magnetic field. The alternating perpendicular magnetic field causes eddy currents to flow in the disk, in a circumferential direction. The eddy currents, in turn cause a magnetic field in a radial direction, thereby resulting in the desired radial uniaxial anisotropy.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: July 13, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Michael L. Mallary, Kazuo Ishibashi, Hiroshi Sato
  • Patent number: 5227582
    Abstract: The disclosed invention relates to a video display system having a device for shielding electromagnetic radiation emitted from electrical wires which connect a video amplifier to a cathode ray tube. The device uses inexpensive unshielded wires which are recessed within a conductive shielding enclosure. The wires are connected to the cathode ray tube by a socket which is positioned at an access opening in the shielding enclosure. The invention further relates to a device for mounting a shielding enclosure to a base using tabs on the enclosure which are captured in an interference fit between the surface of the base and brackets coupled to the base.
    Type: Grant
    Filed: April 6, 1992
    Date of Patent: July 13, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Daniel J. J. Velasco, Dennis C. Robinson, Jeffrey P. Copeland, Ricardo L. Fernandez
  • Patent number: 5224884
    Abstract: A low voltage drop, high current electrical connector which can be releasably mated with associated contacts is disclosed. The connector makes use of elongate contact arms cantilevered in a housing. Each contact arm is made up of at least two beams one of which has relatively high electrical conductivity but relatively poor mechanical spring characteristics. The other has relatively low electrical conductivity but relatively good mechanical spring characteristics. In this way the mechanical and electrical characteristics such as contact force and conductivity may be controlled, balanced and optimized. As one possibility there could be a single spring steel beam backing a stack of sheets of high conductivity copper. As another possibility, there could be sheets of high conductivity copper alternating in a stack with sheets of copper spring which is about half as conductive as pure copper. Instead of a cantilevered spring a coil spring located at the contact surface could be used.
    Type: Grant
    Filed: September 12, 1991
    Date of Patent: July 6, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Michael T. Singer, Robert Noffke, David A. Gilmour
  • Patent number: 5224235
    Abstract: A local area of an electronic assembly, including a single electronic component or a cluster of components mounted to a printed wiring board, is cleaned. A shroud is positioned about the local area and aqueous cleaning solution is sprayed on the lead joints of the electronic component. To remove the cleaning liquids, a vacuum is drawn from the shroud through a central baffle which is positioned close to the electronic component. Adjustable gates are provided about the base of the shroud to permit air flow into the shroud. Adjustment of the gates controls turbulence of the cleaning solution and subsequent direction of air flow for drying of the electronic component, leads and board. Shroud/baffle assemblies are selected and nozzle assemblies are tilted to correspond to different sizes of electronic components.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: July 6, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Peter K. Lison, Keith T. Baines
  • Patent number: 5226150
    Abstract: A write-back cache memory system is disclosed which includes a source of a sequence of memory addresses and a tag store coupled to the source of addresses and accessed by an index portion of said addresses, which produces information relating to the addresses. The write-back cache memory system also includes an error detector for detecting an error in the tag store information. Circuitry is included for reporting an error and saving the index which caused the error if an error is detected but no error has been previously detected. Comparing circuitry is included for comparing the index causing the current error to the previously saved address if an error is detected and an error has been previously detected; and if the address is not the same, then reporting a fatal error; otherwise, if the index is the same, then not reporting a fatal error.
    Type: Grant
    Filed: October 1, 1990
    Date of Patent: July 6, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Michael A. Callander, Linda Chao, Douglas E. Sanders
  • Patent number: 5223996
    Abstract: A combined shock mount frame and seal for a rigid or hard disk drive is constructed by attaching a compressible seal to the edge of a rectangular rigid plastic frame. The seal is provided with a circumferential angular groove on an interior portion having a depth slightly greater than half the thickness of the mounting base of the head and disk assembly of the drive. A circumferential angular ridge is formed on an exterior portion of the seal to conform to the mating edge of the covers of the drive enclosure. The frame is externally dimensioned to fit inside the covers of the drive enclosure. In use, a frame is placed inside a top and bottom cover of the drive enclosure. The mounting base is compressively held in the grooves of the seals of each of the two frames to provide shock resistance to the head and disk assembly and the ridge is compressively held between the mating edges of the covers to hermetically the drive enclosure.
    Type: Grant
    Filed: March 20, 1992
    Date of Patent: June 29, 1993
    Assignee: Digital Equipment Corporation
    Inventors: John D. Read, Charles E. Vaillant
  • Patent number: 5222197
    Abstract: A rule invocation mechanism in an inductive learning engine employing symbolic rules for characterizing a sequence of time-related events. The rules to be tested as hypotheses against new events in the sequence are ranked according to their information content or "quality" value. The efficiency of the rule-to-event pattern matching process for characterizing the new events is increased by not testing a hypothesis if a much better hypothesis already exists. Those hypotheses that characterize events in the sequence are tagged to the event.
    Type: Grant
    Filed: June 28, 1990
    Date of Patent: June 22, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Henry S. Teng, Kaihu Chen, Matthew Wilson, Michael P. Verdeven, Gregory B. Abbruzzese
  • Patent number: 5222029
    Abstract: In a procedure for synthesizing circuit designs, a SYNTHESIZE command in a consequence portion of a rule can be used to control the creation of bit-level instances from a description of a more abstract instance whose interface consists of multi-bit signals. The `synthesize` command has a form that identifies multibit signal/part objects in the data base relative to the current multi-bit instance, which are then synthesized over the range of most-significant to least significant bit. A collection of rules, called macrorules are enclosed within a `synthesize` command. An iteration controlled by "current bit", ranging from least significant to most significant bit, ensues. At each step of the iteration, all macrorules are tested and applied if they are `true`. The macrorules can query whether the current bit is a function of the least or most significant bits. The macrorules can also establish connectivity to any signal bit relative to the current, the least significant or the most significant bit.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: June 22, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Donald F. Hooper, Snehamay Kundu
  • Patent number: 5220271
    Abstract: The disclosed invention regulates the voltage of an output terminal of a multiple output power supply. It operates by diverting current from one output terminal to another output terminal. The invention is less expensive than other alternatives, and has performance advantages over comparably priced alternatives. It may be used in various configurations to maintain an output voltage below a limit, above a limit, or within a range. Additional configurations may be used to regulate the voltages of multiple output terminals.
    Type: Grant
    Filed: March 17, 1992
    Date of Patent: June 15, 1993
    Assignee: Digital Equipment Corporation
    Inventor: John J. Palczynski, Jr.
  • Patent number: 5218557
    Abstract: A new system design tool receives a design representation from a designer, simulates it and compares the simulated operation of the design representation with the desired operation as provided by the operator and identifies causes of discrepancies therebetween. The redesign component performs redesign operations on the design representation in response to the discrepancies. The redesign component includes a plurality of redesign modules each including a redesign solution selection module which receives the identification of causes of discrepancies and the design representation and identifies a redesign solution in response thereto. Each redesign module, in turn, includes at least one redesign operator module which includes a plurality of redesign operators controlled by a redesign control module. The redesign operators each perform a redesign operation in connection with the design representation.
    Type: Grant
    Filed: October 21, 1991
    Date of Patent: June 8, 1993
    Assignee: Digital Equipment Corporation
    Inventor: Evangelos Simoudis
  • Patent number: 5216655
    Abstract: In the manufacture of a high capacity data storage device having multiple surfaces for recording information, the yield of the manufacturing process is improved by providing the storage device with a spare surface. If a recording surface is found to be totally defective, or, substantially worse than the other surfaces, as determined by the manufacturing testing procedures, that surface is, by means of a remapping table, logically retired and the information intended for the defective surface is stored on the logically reallocated spare surface.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: June 1, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Patrick Hearn, Fernando A. Zayas, Antonios E. Prentakis, William D. Lewis
  • Patent number: 5216556
    Abstract: A method for adjusting the tension of a tape in a tape drive is disclosed. The tape is loaded into the tape drive. A test signal is then provided to record test information onto the tape while the tape tension is varied concurrently in a prescribed manner. The test information is read immediately to provide a test readback signal. The test readback signal is processed to determine a functional relationship between the test readback signal and the tape tension. An operating tape tension value is computed based upon the functional relationship. The operating tape tension is implemented on the tape drive in the form of a command signal to a motor means of the tape drive.
    Type: Grant
    Filed: April 26, 1991
    Date of Patent: June 1, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Mitchell R. Steinberg, George A. Saliba
  • Patent number: 5212776
    Abstract: A processor in a computer system is connected, together with one or more control units of peripheral apparatus, to the main memory via a main bus. For a very fast processor the storage capacity of the main memory should be so high that the full physical address can no longer be transported via the main bus in one operation. In that case an additional communication line is provided between the processor and the main memory. In order to enable peripheral apparatus to access the entire main memory anyway, a second memory management unit is connected between the main bus and the main memory.
    Type: Grant
    Filed: April 3, 1989
    Date of Patent: May 18, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Frederik Zandveld, J. A. G. M. Kindervater
  • Patent number: 5212650
    Abstract: A procedure is described for the synthesis and transformation of a logic circuit design, provided by the designers, into a database capable of being used to fabricate the actual circuit. The procedure involves the use of model instances which represent the use of circuit components. The original model instances can be associated with groups of rules that determine resulting configurations of generally different model instances or groups of model instances. The rules are tested and, in the presence of a `true` result, a new model instance (or model instances) can replace one or more original model instances in the data base. The rules associated with a model type (or definition) are rules derived by a design model engineer and can include coupled model instances. The rules can be associated with model definitions, as well as model instances.
    Type: Grant
    Filed: August 3, 1989
    Date of Patent: May 18, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Donald F. Hooper, Snehamay Kundu
  • Patent number: 5210837
    Abstract: A method for translating an initial program flow representation of a computer program into a modified program flow representation examines paths in the initial program flow representation, selects for replication nodes which have multiple predecessor nodes and a single successor node which have never been path search exit nodes and which are neither loop members of successors of loop members. Some of those selected nodes are then replicated and replace the nodes that were replicated. The program flow representation can then be reduced by combining nodes which have a predetermined relationship. This resulting flow representation is well suited for translation into a desired computer language.
    Type: Grant
    Filed: June 15, 1990
    Date of Patent: May 11, 1993
    Assignee: Digital Equipment Corporation
    Inventor: Cheryl A. Wiecek
  • Patent number: 5210829
    Abstract: This invention relates to a tape drive with an electronic buffer which temporarily stores data transferred between the host computer and the tape drive's magnetic tape. More specifically, during a write transaction, in which data is transferred by the host computer to the tape drive for storage, the present invention involves the buffer having an adjustable threshold, or "watermark", which must be reached by the data stored in the buffer before the tape drive begins the operation of ramping the tape up to its write velocity so that it can record the data stored in the buffer. To the extent that the rate at which data is sent to the tape drive from the host computer may vary, the adjustment of the watermark by the tape drive is for the purpose of locating the watermark that is optimal for the data input rate at any given point in time. It does so with its chief objective being the maximization of the tape drives availability to accept data from the host computer whenever the host is ready to send data.
    Type: Grant
    Filed: December 12, 1990
    Date of Patent: May 11, 1993
    Assignee: Digital Equipment Corporation
    Inventor: Haim Bitner
  • Patent number: 5208518
    Abstract: A process and a circuit control the rotational speed of a direct current motor. In particular, the motor may be used to drive magnetic or optical data carriers. The motor is fed with a motor current by a switching device for commutation wherein the motor current induces a magnetic flux which generates the motor torque. The process and circuit increase the motor voltage applied to the motor in the startup or braking phase to a value above the supply voltage. Further, the process and circuit reduce the motor voltage during the commutation phase so that commutation switching may occur in a reduced-current condition.
    Type: Grant
    Filed: November 15, 1991
    Date of Patent: May 4, 1993
    Assignee: Digital Equipment Corporation
    Inventors: Hans Grapenthin, Horst Haug
  • Patent number: D335501
    Type: Grant
    Filed: January 9, 1991
    Date of Patent: May 11, 1993
    Assignee: Digital Equipment Corporation
    Inventor: Robert T. Faranda