Patents Assigned to Digital Equipment Corporation
  • Patent number: 6105028
    Abstract: A method and apparatus for enabling access of a document on a remote network device by a local computer includes an interceptor for intercepting a request (from a web browser on the local computer system) for accessing the document. The interceptor responsively ascertains whether the local computer is connected to a network and, if connected to the network, downloads the document into memory of the local computer system. If the local computer is not connected to the network, the method and apparatus locates the document in the local memory of the local computer. Once downloaded or located, whichever the case may be, the document may be utilized by the user, such as by displaying the document on a display device.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: August 15, 2000
    Assignee: Digital Equipment Corporation
    Inventors: David J. Sullivan, William Joseph Gauvin, Edward James Taranto
  • Patent number: 6101516
    Abstract: A pipelined floating point processor including an add pipe for performing floating point additions is described. The add pipe includes a circuit to predict a normalization shift amount from examination of input operands, a circuit to determine the "Sticky bit" from the input operands, and a rounding adder which adds a pair of operands and rounds the result in a single pipeline stage operation. The rounding adder incorporates effects due to rounding in select logic for a series of carry select adders. The adder also aligns the datapath to permit economical storage and retrieval of floating point and integer operands for floating point or conversions operations. The floating point processor also includes in the adder pipeline a divider circuit include a quotient register having overflow quotient bit positions to detect the end of a division operation.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: August 8, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Gilbert M. Wolrich, Timothy C. Fischer, John J. Ellis
  • Patent number: 6101288
    Abstract: In a computerized method, a set of radial distortion parameters are recovered from a single image by selecting arbitrarily oriented straight lines in a single image using an input device. Then, objective functions in Cartesian form are minimized using a least-squares fit formulation to recover the set of radial distortion parameters.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: August 8, 2000
    Assignee: Digital Equipment Corporation
    Inventor: Sing Bing Kang
  • Patent number: 6101543
    Abstract: A new pseudo network adapter is disclosed providing an interface for capturing packets from a local communications protocol stack for transmission on the virtual private network. The system further includes a Dynamic Host Configuration Protocol (DHCP) server emulator, and an Address Resolution Protocol (ARP) server emulator. The new system indicates to the local communications protocol stack that nodes on a remote private network are reachable through a gateway that is in turn reachable through the pseudo network adapter. The new pseudo network adapter includes a transmit path for processing data packets from the local communications protocol stack for transmission through the pseudo network adapter. The transmit path includes an encryption engine for encrypting the data packets and an encapsulation engine for encapsulating the encrypted data packets into tunnel data frames.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: August 8, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Kenneth F. Alden, Mitchell P. Lichtenberg, Edward P. Wobber
  • Patent number: 6097593
    Abstract: A semi-mobile desktop personal computer incorporating the features of a desktop personal computer with the mobility of a mobile personal computer. The computer includes a system enclosure attached to a storage enclosure, the storage enclosure extends outside the system enclosure and provides stability for the system enclosure by engaging the surface on which the system enclosure has been placed for use.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: August 1, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Robert T. Faranda, Bradford G. Chapin
  • Patent number: 6098179
    Abstract: A method and apparatus for performing error detection in a network is disclosed. An error counter is stored in a common memory location accessible by all nodes. The error counter includes separate partitions associated with each node in the network. Each partition includes two error counter values representing, respectively, sending and transmission error counts, for a corresponding node. No global locking mechanism is required to synchronize access to the commonly accessed error counter. Rather, access to the error counter is provided by having code executing on each node adhering to rules regarding the types of access to the various partitions in the error counter. Each node may read from any partition, but may only write to its own partition.
    Type: Grant
    Filed: January 22, 1998
    Date of Patent: August 1, 2000
    Assignee: Digital Equipment Corporation
    Inventor: Paul Karl Harter, Jr.
  • Patent number: 6097882
    Abstract: A client-server network including a number of client computer systems, each of the client computer systems having a network interface, a number of server computer systems, each of the server computer systems having a network interface, and a replicator system connecting the client computer systems to the server computer systems, the replicator system transparently processing a number of requests from the client systems to a number of services resident in the server systems.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: August 1, 2000
    Assignee: Digital Equipment Corporation
    Inventor: Jeffrey C. Mogul
  • Patent number: 6091897
    Abstract: A computer system for executing a binary image conversion system which converts instructions from a instruction set of a first, non native computer system to a second, different native computer system, includes an run-time system which in response to a non-native image of an application program written for a non-native instruction set provides an native instruction or a native instruction routine. The run-time system collects profile data in response to execution of the native instructions to determine execution characteristics of the non-native instruction. Thereafter, the non-native instructions and the profile statistics are fed to a binary translator operating in a background mode and which is responsive to the profile data generated by the run-time system to form a translated native image. The run-time system and the binary translator are under the control of a server process.
    Type: Grant
    Filed: January 29, 1996
    Date of Patent: July 18, 2000
    Assignee: Digital Equipment Corporation
    Inventors: John S. Yates, Scott G. Robinson, Mark Herdeg
  • Patent number: 6092180
    Abstract: In a method for scheduling instructions executed in a computer system including a processor and a memory subsystem, pipeline latencies and resource utilization are measured by sampling hardware while the instructions are executing. The instructions are then scheduled according to the measured latencies and resource utilizations using an instruction scheduler.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: July 18, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Jennifer-Ann M. Anderson, Jeffrey Dean, James E. Hicks, Jr., Carl A. Waldspurger, William E. Weihl
  • Patent number: 6092101
    Abstract: A computer implemented method for filtering mail messages in a distributed computer system. The distributed mail service system includes a plurality of client computers connected to a mail service system via a network. Mail messages are stored in message files of the mail service system. Each mail message is parsed and indexed to generate a full-text index of the mail service system. A query is composed, the query includes terms and operators. The query is stored in the mail service system as a named filter query. A new mail message received by the mail service system is parsed, indexed and searched to determine if the content of the new mail message does not match on the named filter query, in which case an inbox label and an unread label to the new mail message.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: July 18, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Andrew D. Birrell, Edward P. Wobber, Michael Schroeder
  • Patent number: 6088771
    Abstract: A technique reduces the latency of a memory barrier (MB) operation used to impose an inter-reference order between sets of memory reference operations issued by a processor to a multiprocessor system having a shared memory. The technique comprises issuing the MB operation immediately after issuing a first set of memory reference operations (i.e., the pre-MB operations) without waiting for responses to those pre-MB operations. Issuance of the MB operation to the system results in serialization of that operation and generation of a MB Acknowledgment (MB-Ack) command. The MB-Ack is loaded into a probe queue of the issuing processor and, according to the invention, functions to pull-in all previously ordered invalidate and probe commands in that queue. By ensuring that the probes and invalidates are ordered before the MB-Ack is received at the issuing processor, the inventive technique provides the appearance that all pre-MB references have completed.
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: July 11, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Simon C. Steely, Jr., Madhumitra Sharma, Kourosh Gharachorloo, Stephen R. Van Doren
  • Patent number: 6085296
    Abstract: A method of managing computer memory pages. The sharing of a program-accessible page between two processes is managed by a predefined mechanism of a memory manager. The sharing of a page table page between the processes is managed by the same predefined mechanism. The data structures used by the mechanism are equally applicable to sharing program-accessible pages or page table pages.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: July 4, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Nitin Y. Karkhanis, Karen Lee Noel
  • Patent number: 6085292
    Abstract: A cache includes an address cache for storing memory addresses. An address queue is connected to the address cache for storing missed addresses in the order that the address cache is probed. A memory controller receives the missed addresses from the address queue. A data queue receives data stored at the missed addresses from the memory controller. A probe result queue is connected to the address cache for storing data cache line addresses and hit/miss information. A multiplexer connected to the data cache, the data queue, and the probe result queue selects output data from the data cache or the data queue depending on the hit/miss information.
    Type: Grant
    Filed: June 5, 1997
    Date of Patent: July 4, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Joel J. McCormack, Kenneth W. Correll, Barton W. Berkowitz, Christopher C. Gianos
  • Patent number: 6084455
    Abstract: A high-speed CMOS latch includes at each storage node a pull-up P-transistor with its gate tied to a dynamic node, and a pull-down N-transistor with its gate controlled by the inverse of the states of the remaining dynamic nodes. The P-transistor drives the storage node high to VDD, and the N-transistor drives the node low to VSS, as appropriate. During evaluation, one dynamic node discharges to a low state and in response each storage node is driven relatively quickly to the desired high or low state through either the associated pull-up or pull-down transistor. Precharging P-transistors drive the dynamic nodes high during precharge periods. As the dynamic nodes go high, they turn off all of the pull-up and pull-down transistors that drive the latch storage nodes, and the latch retains the evaluated state of the dynamic nodes until the start of the next evaluation cycle. Accordingly, the latch does not require a separate clock.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: July 4, 2000
    Assignee: Digital Equipment Corporation
    Inventor: Mark D. Matson
  • Patent number: 6081909
    Abstract: A method of encoding a message including a plurality of data items, includes identifying maximum and minimum numbers of first edges to be associated with data items. A first distribution of different numbers of first edges, ranging from the maximum to the minimum number of first edges, to be associated with the data items is computed. A first associated number of first edges, within the range, is established for each data item, the different numbers of first edges being associated with the data items according to the computed first distribution. A maximum and minimum number of second edges to be associated with redundant data items are identified. A second distribution of numbers of second edges, ranging from the maximum to the minimum number of second edges, to be associated with the redundant data items is computed.
    Type: Grant
    Filed: November 6, 1997
    Date of Patent: June 27, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Michael G. Luby, Mohammad Amin Shokrollahi, Volker Stemann, Michael D. Mitzenmacher, Daniel A. Spielman
  • Patent number: 6081268
    Abstract: Using an input device of a computer system, a graphic drawing is defined to include at least one graphic component. The graphic component is subject to a plurality of constraints. At least one of the constraints is redundant with respect to the other constraints. Approximate linear equations are substituted for the constraints. A subset of the equations are selected to determine a converging solution for the redundantly constrained graphic drawing.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: June 27, 2000
    Assignee: Digital Equipment Corporation
    Inventors: C. Allan Heydon, C. Gregory Nelson, Eric H. Veach
  • Patent number: 6079021
    Abstract: A computer implemented method provides access to processes and data using strengthened password. During an initialization phase, an access code is stored in a memory of a computer system. The access code is an application of a one-way hash function to a concatenation of a password and a password supplement. The size of the password supplement is a fixed number of bits. During operation of the system, a user enters a password, and the one-way hash function is applied to concatenations of the password and possible values having the size of the password supplement to yield trial access codes. Access is granted when one of the trial access codes is identical to the stored access code.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: June 20, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Martin Abadi, Roger Michael Needham, Thomas Mark Angus Lomas
  • Patent number: 6078923
    Abstract: A data processing system includes at least one central processor for executing instructions of software programs. In addition the data processing system includes a memory containing a data structure common to the software programs. The common data structure includes a compressed index data structure. The index structure stores index entries referencing a database. The database includes multiple records, each having a unique address in the database. Each index entry includes a word entry if the index entry represents a compressed encoding of a unique portion of information sequentially parsed from the database. The word entry is followed by one or more location entries which reference occurrences of the portions of information. Each index entry includes a metaword entry if the index entry represents a unique attribute of one or more related words. The metaword entry is followed by one or more location entries referencing occurrences of the attributes.
    Type: Grant
    Filed: December 16, 1997
    Date of Patent: June 20, 2000
    Assignee: Digital Equipment Corporation
    Inventor: Michael Burrows
  • Patent number: 6078740
    Abstract: In a computerized method for predicting a particular user preference for an item based on observations made about the item by other users, client computers are used to enter the observations about the items. The observations are forwarded to a server computer via a network. The observations are collected in a database of the server computer. Using factor analysis, a solver module of the server computer analyzes the observations to generate a model of the observations. The models are distributed to the client computers via the network. The client computer makes predictions of preferences of the particular user using the models.
    Type: Grant
    Filed: November 4, 1996
    Date of Patent: June 20, 2000
    Assignee: Digital Equipment Corporation
    Inventor: John D. DeTreville
  • Patent number: 6078487
    Abstract: A circuit which protects an integrated circuit (IC) device from damage due to electrostatic discharge (ESD). The protection circuit includes an N-channel metal oxide semiconductor field effect transistor (MOSFET) clamping device and a gate modulation circuit. The source and drain of the MOSFET clamp are connected between an input/output (I/O) pad of the IC and a ground reference voltage. During normal operation of the IC, the gate modulation circuit disables the MOSFET clamp by connecting its gate terminal to a ground reference voltage. This permits signal voltages to pass between the I/O pad and any operating circuits connected to the pad. During an ESD event, the gate modulation circuit connects the gate to the I/O pad, which enables the MOSFET clamp, causing any ESD voltages and resulting currents to be shunted through the MOSFET clamp to ground. As a result, the ESD clamp reaches its clamped-to snapback voltage via an increase in MOSFET channel current, and not via junction breakdown.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: June 20, 2000
    Assignee: Digital Equipment Corporation
    Inventors: Hamid Partovi, Kaizad R. Mistry, David B. Krakauer, William A. McGee