Abstract: A data processing system includes an operating system, a graphical user interface and a plurality of applications programs. The graphical user interface generates a window relating to an executing application programs. Menu items relating to an application program may be represented by an icon. A selected group of objects is defined over a portion of the menu and represented by a metaphor. The graphic metaphor, here an icon ring is displayed on a display device. The icon ring is evocative of an ordered arrangement of items of the selected group, includes the icon for a particular object open to selection, and is subject to direct manipulation for reordering of the underlying selected group.

Abstract: Disclosed is an apparatus for blanking the trailing edge of a sensed current signal taken from the leading leg of a full bridge voltage regulator. Switching elements in the arms of the full bridge voltage regulator cycle on and off in staggered phases under control of a pulse width modulation controller to provide zero voltage drop switching of the elements. With trailing edge blanking of the sensed current signal, a control waveform is generated for delivery to the pulse width modulation controller which mimics a sensed current signal taken from the lagging leg of the bridge. Such a current waveform exhibits a clear peak enhancing circuit stability thereby permitting use of leading leg current sensing to improve power supply efficiency.

Abstract: Conversion of a double-byte representation of a character in a first interchange code to a double-byte representation of the character in a second interchange code is taught. The double-byte representation is used to provide column and row indices into a conversion array. This occurs through comparison of the first and second bytes of the representation to first and second national language verification arrays, respectively. The first byte is compared against the first national language verification array to return a first value. The second byte is compared against the second national language verification array to return a second value. The first and second values are then evaluated against first and second range limits, respectively, which, if met, validate the returned values as indices into a national double-byte translation table.

Abstract: A detection circuit that does not vary with the supply voltage is formed by measuring the voltage generated at the terminals of a diode (1) which is reverse biased and is supplied by a constant current generator (2). Furthermore, the generator (2) is improved by a current consumption limitation circuit (5). This circuit is particularly designed to be implanted in CMOS technology on the same substrate as a memory circuit or a microprocessor circuit.

Abstract: A method of passing data between objects located distributed among a plurality of virtual address space domains established by processes executing on a data processing system comprises several steps. First, a session initiation message from a source object in a domain is broadcast to other objects in the domain. Responsive to receipt of the session initiation message by a domain agent (a type of object) for the domain, forwarding the session initiation message from the domain agent to each of a plurality of domain agents in other virtual address space domains. Responsive to receipt of the session initiation message by the domain agent for a second domain, transmitting the session initiation message from the domain agent for the second domain to an agent object in the second domain for the source object.

Abstract: Decompression of video segments from a sequence of differential frames is done by selected scaling of frame resolution and color depth. A frame header indicates the computational complexity of decompression of a frame, allowing selection of scales for output resolution and color depth. Decompression proceeds by retrieving a frame from the compressed video stream in elementary units. An elementary unit is characterized by types, including an unchanged type, a homogeneous type, a pattern type and a predetermined pattern type. For a retrieved elementary unit of the unchanged type, an output pointer to a display buffer is moved by an elementary unit scaled by the output resolution scale. For a retrieved elementary unit of the homogeneous type, a color retrieved from the compressed video stream is applied to an area in the display buffer corresponding to an elementary unit scaled by the output resolution scale.

Abstract: A process for coding a plurality of compressed video data streams in a time ordered sequence. Each compressed data stream includes coding of frame to frame differences of a video segment, which are represented as a compressed M.times.N exclusive-OR plane of pixel change values and location displacement control values for an output pointer into a decompressed video frame. By coding frame to frame differences in an exclusive-OR values, the replay process is made bidirectional, allowing for both forward and reverse playback of the video segment.

Abstract: A data processing system provides a graphic user interface on which is displayed a scroll bar including a current value position and showing sequential numerical values adjacent to the current value in the current value position. Selection graphics provide for user selection of values, and to expand or reduce value resolution. A graphic metaphor for a spin button provides for incrementing or decrementing the range of values within the display field of the scroll bar.

Abstract: A method of operating bridge circuit for control of an inductive load is disclosed. The bridge circuit has a pair of input terminals for connection across a power source and a pair of output terminals for connection across the inductive load. Each arm of the bridge includes a transistor switch connecting an input terminal with an output terminal. Clamp circuits are connected to each pair of input and output terminals, taking inputs therefrom and responding to a transition through a predetermined voltage differential between the terminals for driving the transistor switch connecting the output terminal to the remaining input terminal, thereby limiting the output terminal to a predetermined voltage level.

Abstract: Disclosed is a logic output signal generating integrated circuit having a plurality of output drivers connected in parallel between a power bus and a ground bus. Each output driver has a pull up device disposed between the power bus and an output terminal and a pull down device disposed between the output terminal and the ground bus. Output drivers are paired for the reception of control signals. Control gates to the pull up device and the pull down device for one output driver in a pair is connected to receive an on-chip logic signal. The second output driver of the pair has the complement of that logic signal applied to the control gates of its pull up and pull down devices. An inverter operates on the logic signal to provide the complement. The load is divided between the output drivers for the true signals and those for the complementary signals.

Abstract: Calibration of the write signal power level applied to a transducer for marking a moving media to optimize a later recovered read-back signal is provided. An optimized read-back signal is one where the peak-to-peak amplitude of the read-back signal is maximized. The method provides marking test patterns on the recording media at a plurality of discrete, selected write signal power levels of the marking source, developing a read-back signal from the test pattern marks, correlating portions of the read-back signal with the write signal power levels and solving a relationship of the formW.sub.c =W.sub.o -KB.sub.2 /2B.sub.3where W.sub.c is the calibrated write signal power level W.sub.o is an offset write signal power level. K is a minimum differential between write signal power levels B.sub.2 and B.sub.3 are parameters derived from a least squares fit of a second order polynomial equation to data provided by correlating read-back signals with write signal power levels.

Abstract: A method of converting a digital video signal having a luminance component for each pixel of a frame and two color difference components for contiguous groups of pixels in the frame into a video signal having three color components for each pixel is disclosed. Two color lookup tables are provided, each being indexed by a combination of the luminance level for a pixel and a color difference component for the group including the pixel. Entries in each color lookup table include a component value for one color and a subcomponent contributing to a component value for another color. The method provides combining the luminance components and color difference components for each pixel represented in the compressed digital video signal to retrieve the color component values for the three color video signal. Two colors are extracted directly from the lookup tables. The third color component is generated by combining subcomponent values extracted from the tables.

Abstract: A refrigeration system servicing apparatus includes a digital controller, a vessel for storing and pressurizing refrigerant, a solenoid actuated valve responsive to the digital controller for selective connection of the refrigeration system to a vacuum source, a solenoid actuated valve responsive to the digital controller for connection of the vessel to the refrigeration system, a pressure sensor for providing pressure readings to the digital controller from the low pressure side of the vacuum source, a pressure sensor for providing pressure readings to the digital controller from the vessel and means for quantifying the refrigerant in the Vessel. Three operational modes provided for are: a "vacuum" mode, during which residue material in the refrigeration system is boiled away; a "charge oil" mode, during which lubricant is added to the refrigeration system; and a "charge refrigerant" mode, during which refrigerant is added to a refrigeration system.

Abstract: Identification of a target object within an object hierarchy is made in response to user selection. The prior attribute values for the target object are then displayed on a display device. Upon user selection, new object attribute values are generated for the target object. A propagation group for the new object attribute values is made in response to user designation of relating factors and the new object attribute values are applied to all objects within the related group.

Abstract: A system for making procedure calls can be used with a network of computers. An application program on a local node calls a desired library procedure. The library procedure can be available on the local node or a remote node, and the location need not be known by the application. If the library procedure is available on a remote node, a remote router procedure communicates a procedure identifier to the remote node. The procedure is executed, and any results are returned to the locol node, to be returned to the application program.

Abstract: A system suitable for use on a computer network provides a user interface on a local node and an application to be run on a remote node. An application for accepting input from the user and translating it to appropriate commands for the remote application is divided, and located partially on the local node and partially on the remote node. That portion located on the local node gathers any information required from the user and transmits it to the portion located on the remote node in an efficient manner. The remote location portion uses the transmitted information to interface with the remote application and obtain results. The results are collected and transmitted to the local portion, from which they are returned to the user.

Abstract: A windowing system provides an interface between application programs and non-programmable terminal drivers. The system presents logical windows to the applications program, each of which are represented internally by at least two separate parts. The first part includes the border and non-scrollable text for a logical window, while the second part includes scrollable text for the window. Through calls to the display driver, the windowing system manipulates these separate parts so that they are displayed on the screen as a single window.

Abstract: A system and method suitable for use with a rule-based expert system maintains a history of execution states through which the expert system progresses during execution. A user can select a previous execution state for roll back, and later states maintained in the history are undone in reverse order until the selected state is reached. If desired, a user can define a breakpoint to which the system is to be rolled back. The corresponding executable state is determined from a retained history of all potential breakpoints, and the system is then rolled back to such corresponding executable state.

Abstract: A method for use with a rule-based expert system provides a technique for determining a recent previous consistent state of execution of the expert system after a change is made to a rule or variable. Several queues contain state history information of an inference engine. When changes are made to a rule or variable, these history queues are examined to determine a recent consistent state. If the current state is inconsistent due to the change, the user can be informed that the system is now in an inconsistent state.

Abstract: A system and method for translating vector description displays into raster images writes the vector description image, having some number of displayable colors, into more than one intermediate image file. Each intermediate image file can define only a number of colors which is smaller than the number of colors in the original display. Separate color translation tables are used to generate each intermediate file. Proper selection of the color translation tables causes each intermediate file to contain a portion of the full color information. The intermediate files are translated to intermediate raster files which are then combined into a single raster image which retains all of the colors of the original vector description image.