Abstract: A method for controlling the impedance of drivers controls the output impedance of drivers by coupling the drivers to a impedance control circuit. Accordingly, a desired driver output impedance can advantageously be established and maintained over a wide range of variations in operating conditions and manufacturing processes. Thereby shortening the signal settling time and increasing the attainable signaling frequency.

Abstract: Quotient digit selection logic is modified so as to prevent a partial remainder equal to the negative divisor from occurring. An enhanced quotient digit selection function prevents the working partial remainder from becoming negative if the result is exact, choosing a quotient digit of zero instead of a quotient digit of one when the actual partial remainder is zero. Using a five bit estimated partial remainder where the upper four bits are zero, a possible carry propagation into fourth most significant bit is detected. This can be accomplished by looking at the fifth most significant sum and carry bits of the redundant partial remainder. If they are both zero, then a carry propagation out of that bit position into the least significant position of the estimated partial remainder is not possible, and a quotient digit of zero is chosen. This provides a one cycle savings since negative partial remainders no longer need to be restored before calculating the sticky bit.

Abstract: The present invention comprises a method and apparatus for receiving data analysis instructions from a user and for displaying results of the data analysis to the user. In one embodiment, the invention provides a series of interface windows displayed on a computer display screen. A first window allows a user to select one or more specification files comprising reference data specifying capabilities and or resources with which other data is to be compared. A second window allows the user to select one or more data files to be compared to the one or more specification files selected using the first window. A third window allows the user to interactively select the type of analysis to be performed and provides the results of the selected analysis to the user. The third window also allows the user to interactively apply one or more filters to the results and to select the manner (view) in which the results are displayed.

Abstract: A multi-display video system for ensuring the proper synchronization of scene switching. Before each display switches to pixel data corresponding to the next scene to be rendered, new pixel data is written into a currently unused bank of frame buffer memory within a corresponding graphics accelerator. When each graphics accelerator in the video system has completed writing the new pixel data to its respective frame buffer, the scene switch may take place. Each graphics accelerator is configured to display an image corresponding to the next scene in response to the indicator output signal indicating that the pixel data updates for all graphics accelerators are complete.

Abstract: An on-chip resistance to an input current of an input signal includes a parallel transistor resistor and a control circuit for biasing the transistors of the parallel transistor resistor. The parallel transistor resistor includes first and second transistors of first and second types. Each transistor includes first and second current handling terminals and a control terminal. The control terminals are coupled to receive control signals from the control circuit. The first current handling terminals are coupled to provide an input node for receiving an input signal, and the second current handling terminals are coupled to provide an output signal. The control circuit is coupled to provide the first and second control signals for biasing the respective first and second transistors so that a first derivative of a resistance of the parallel transistor resistor in relation to an input-to-output voltage is zero at a selectable operation point.

Abstract: A method and apparatus for translating a virtual address to a physical address. A virtual address to be translated has a virtual page offset and a virtual page number. The virtual address to be translated addresses a page of memory. The size of this page is unknown. There are L different possible page sizes where L is a positive integer greater than one. Each of the L different page sizes is selected to be a test page size and a test is performed. During the test, a pointer into a translation storage buffer is calculated. The pointer is calculated from the virtual address to be translated by assuming that the virtual address to be translated corresponds to a mapping of the test page size. The pointer points to a candidate translation table entry of the translation storage buffer. The candidate translation table entry has a candidate tag and candidate data.

Abstract: Symmetry in a filter is used to reduce the complexity of an interpolator or a decimator and to simplify derivation of resulting discrete samples. In particular, an inverse relationship between weights applied to two samples is recognized and exploited. An inverse relationship is recognized when a first weight is associated with a first of the samples and a second weight is associated with a second of the samples and a weight which is equivalent to the first weight is associated with the second sample and a weight which is equivalent to the second weight is associated with the first sample. The inverse relationship is exploited by forming two composite weights of the first and second weights and weighting composite sample signals with the composite weights. A first of the composite weights has a value which is one-half of the sum of the values of the first and second weights. A second of the composite weights has a value which is one-half of the difference of the values of the first and second weights.

Abstract: A computer system program including an operating system and a plurality of system service modules generates a number of status messages representing selected milestone events while it is being loaded and run, including progress advisories and technical advisories. User-friendly icons are displayed on a display monitor in response to the progress advisories, indicating which milestone event is occurring and how much of the event has been completed. If there is a failure in loading the system program, a user can provide service personnel with an accurate evaluation of the system condition by reporting which icon was displayed last on the monitor. Technical advisories such as audit records which are not relevant to a user are stored as entries in a silent log for possible later use by service personnel.

Abstract: A digital data transfer system comprises a source module and a destination module interconnected by an information transfer medium. The source module initiates a transfer operation in which it transfers a data item and an associated address over an information transfer medium. The address having an aperture identification portion that identifies one of a plurality of apertures. The destination module receives the data item and the associated address from the information transfer medium during the transfer operation, the destination module using the one of the plurality of apertures identified by the aperture identification portion to generate an aperture value for association with the data item. The source module can also initiate a retrieval operation, during which it transfers an address over the information transfer medium to retrieve previously transferred information.

Abstract: A pointer-specific instruction variant replacement mechanism facilitates an exact write barrier, i.e., a write barrier specific to pointer stores and transparent to non-pointer stores. Pointer store specific instruction replacement allows some implementations to provide an exact barrier specific to the particular set of intergenerational pointer stores that are of interest to a particular garbage collection method or combination of methods. The exact identification of pointer stores herein does not require tags encoded in-line with collected memory storage and does not require non-standard word sizes to support such tags. In one embodiment, a non-quick to quick translator cache provides pointer specific store instruction replacement. In another, self modifying code provides pointer specific store instruction replacement.

Abstract: A memory management system for a fault tolerant computer system. The memory management system includes a first recording mechanism which can be activated to record memory update events; a second recording mechanism which records at least a limited number of memory update events; a fault input for a fault signal to activate the first recording mechanism in the event of a fault event; and a memory reintegration mechanism to reintegrate at least parts of memory identified in the first and second recording mechanisms. Preferably, the recording of memory updates (writes) is not based on recording each address accessed, but rather on memory segments (pages) updated (written to). Further, a fault tolerant computer system includes a plurality of synchronous processing sets, each having a processor with internal memory and operating in lockstep, and an out of sync detector for detecting an out-of-sync-event and for generating an out-of-sync signal.

Abstract: A system for enhancing security of electronic documents distribution wherein electronic documents are fingerprinted with one or more modifications to the document text. The text modifications may be selected so that multiple copies of the same master document will all have the same meaning. By examining text modifications in an unauthorized copy, one can identify the authorized source. The ability to detect the source of a copy discourages unauthorized distribution. This electronic document distribution system may find particular application on the Internet.

Abstract: A computer-implemented method and system for of retrieving information. A first file of information is received which includes a first markup language to identify contents of the information. Responsive to the receiving the first file of information, the first file of information is parsed to generate a list of profiles, and at least one corresponding topic for each of the list of profiles. A second file in a second markup language is created containing the list of the profiles and at least one corresponding third file is created in a third markup language for the at least one corresponding topic for each of the list of profiles. The second file contains anchors referencing each at least one corresponding third file, and first markup instances in the first file of information are converted to second markup instances in either the second file or the third fie.

Abstract: A microprocessor for extracting one or more arbitrary channels of data from an image of any number of multiple channels with substantially minimized processing cycles per byte. Each channel of an image is preferably sampled with a predetermined data length. Subsequently the microprocessor partitions each of said sampled data according to a partitioning criterion into a plurality of partitioned components and combines a plurality of said partitioned components to form a data variable that is formed only with data components indicative of a selected channel of the image.

Abstract: A method and system for providing access to multimedia content on-line which is updated virtually simultaneously with the vendor's update process. By a user accessing a page on the World Wide Web, for example, data (encrypted and unencrypted) and instructions are automatically downloaded to a user's computer system for quick access. Depending upon the user's computer system (LAN or a stand-alone personal computer), "applets" containing data and instructions are stored for immediate access. In a Karaoke application of this invention, where the user desires to access songs which are most popular at a given time, the user accesses a page where a song list and other information is displayed on a display apparatus. When the user clicks on a particular song of the song list, the applet executes an authentication request. If the user is authenticated, the authentication is downloaded as part of the applet containing the desired multimedia content (or separately depending upon the circumstances).

Abstract: A CPU adapted to calculate a checksum simultaneously on multiple values packed into a single register. An adder is provided which adds a number of values packed into a first register to a number of packed values from a second register. The adder is constructed, or partitioned, so that the values do not propagate their carry bit to the next value. A special carry bit adder is provided which will add a carry bit out of each partitioned portion back into the sum value to generate the sum required by the checksum protocol.

Abstract: A dynamic pulse register which uses a standard clock signal and exhibits reduced propagation delay. The dynamic pulse register includes a precharge logic block configured to precharge an evaluate signal and an evaluate complement signal during a precharge phase. During an evaluate phase, a pulldown logic block is configured to discharge either the evaluate or evaluate complement signal in response to a valid data input to the pulse register. A driver logic block is configured to convey a data out signal as the complement of the evaluate complement signal, and a data out complement signal as the complement of the evaluate signal. Either the data out signal or the data out complement signal is thus charged (thereby producing the rising edge of the output pulse) in response to the discharging performed by the pulldown logic block.

Abstract: Apparatus, methods, and computer program products that disclose an entity chooser (similar to a file chooser) that uniformly presents heterogeneous entities accessed through different access methods. The invention allows a computer user to select, using a single interface, an entity from a collection of entities representing accessible information. For example, the invention can simultaneously and uniformly present entities located on a filesystem along with entities found on a network to the user for selection.

Abstract: A devtmp device driver provides the functionality of temporary files by representing a virtual device and including the virtual device among several devices within which a file system can store files. Rather than storing data in and retrieving data from a physical device, the devtmp device driver stores data in and retrieves data from anonymous storage through a swap file system which manages anonymous storage for a virtual memory system. A file system uses the devtmp device driver in the same manner the file system uses conventional device drivers which store data in and retrieve data from secondary storage devices. Since the devtmp device driver represents a virtual device whose data are stored in anonymous storage managed by the swap file system, the total amount of storage available for storing data of temporary files is shared among the various components of a computer process to successfully satisfy various needs of various computer processes.

Abstract: Mapping of pixels of a graphical object to a destination graphical image buffer is achieved by precalculating relative weights of object pixels near a subject pixel and storing the precalculated relative weights in a table and by determining weights of specific object pixels during processing by a table lookup of the predetermined weights according to a fractional portion of an object pixel address. A partitioned coefficient, which represents the relative weights of two or more object pixels, is retrieved from the weight table and used in a partitioned multiplication operation in a processor to weight each of the two or more object pixels substantially simultaneously. Weights associated with two or more object pixels are formed by partitioned multiplication of a partitioned horizontal weight word and a partitioned vertical weight word.