Abstract: A protocol for transferring audio data and control/status data between audio functional units. The protocol involves multiplexing the audio data and control/status data. The multiplexed data is then transferred between a first audio unit and a second audio unit on two wires, each corresponding to the direction of data flow, and according to a clock rate and a synchronization pattern on third and fourth wires respectively.

Abstract: A method and apparatus for transferring control between application programs. A messaging means is provided which allows a first application program to indicate to the messaging means that a second application program should assume control. The messaging means receives the message and performs an orderly shutdown of the first application program and messages the second application program that it should commence operation. Upon valid and proper operation of the second application program, the first application program is caused to be suspended, and the second application program is invoked.

Abstract: A composite dictionary data compression process for use with a computer system comprising the steps of: receiving into the computer system an uncompressed input data string; searching a composite dictionary to detect for a dictionary data string matching the uncompressed input data string, the composite dictionary comprising a fixed dictionary and an adaptive dictionary; and modifying the adaptive dictionary in response to whether a matching dictionary data string is detected.

Abstract: A method and apparatus for detecting an escape sequence to cause a modem to switch from a data transmission mode to a command mode. The escape sequence precedes a command instruction. The escape sequence comprises a first predetermined set of characters and a second predetermined set of characters.

Abstract: A method and apparatus in accordance with the present invention comprises the process and means for receiving input strokes made with a stylus on a screen of a pen-based computer and determining if the strokes comprise a text object. When the strokes do form a text object, a rating for each existing displayed paragraph is assigned to identify a probability level that an insert location is within the paragraph. Determining a rating involves comparing the bounds of the text object to extended bounds of the existing paragraph, and the input strokes of the text object to the input strokes of the preceding text object. When the rating is completed for each paragraph, an insert location within the highest rated or most probable existing paragraph is then identified, and the text object is inserted at this insert location. A new paragraph is formed with the text object at a location based on the input strokes when a most probable paragraph is not identified.

Abstract: An integrated and drop-in EMI filter that features common-mode and differential-mode noise filtering capabilities is disclosed. The common-mode portion and the differential-mode portion of the filter are independent of each other in that the two filter portions may be made out of different ferrites, also in that, the an increase in the filtering capability in one mode, such as having an increased number of turns in the winding, would not affect or reduce the filtering capability of the other mode, such as reducing the overall throughhole depths a conductor travels.

Abstract: An operating system software architecture, implemented in an object-oriented design, supports and processes color. The object-oriented design has two levels, one being a class (TColor) defining a virtual abstract base class and being a container class containing calibrated colors, the other being a class (TDeviceColor) defining a virtual abstract base class and a container class containing uncalibrated colors. Several calibrated color classes including a class (TXYZColor) defining XYZ color space descend directly from class (TColor), several uncalibrated color classes including a class (TRGBColor) descending directly from class (TDeviceColor), a class (TColorGamut) storing color gamut information of peripheral devices that may interface with the architecture, and a class (TColorProfile) storing tonal reproduction curves of the peripheral devices provide data structures, together with method functions for various color processing.

Abstract: A method and system for preparing interactive references having pages which can be displayed on the screen of a pointer-based computer system. Some of the reference's pages have "live" features or icons which the user can select to cause various actions such as moving to other locations within the reference, displaying dialog boxes on the screen, etc. The present invention converts a document containing appropriate comments into a set of instructions for an interactive reference according to a defined sequence of steps. First, the document is separated into content blocks delineated by content commands. Each such block can be separately formatted for use in the interactive reference. Next, the system creates page descriptions in which the content blocks are arranged on pages whose boundaries are defined by the display screen of the computer system on which the interactive references will be displayed.

Abstract: A method and system are disclosed for efficiently translating data from one known data sequencing arrangement to an alternative sequencing arrangement. The method consists of the steps of generating a source sequence signal which identifies the ordering of units within the source sequence, generating a destination sequence signal which identifies the ordering of units within the destination sequence, and combining the source signal and destination signal to produce a permutation signal which defines the relationship between the source sequence and the destination sequence. Once the permutation signal has been defined, this permutation signal is applied to the source sequence to allow the reordering of the source sequence into the desired destination sequence. A reordering circuit is used to rearrange the source sequence units into the desired destination sequence units utilizing the permutation signal generated in the present invention.

Abstract: A method for selecting objects displayed on a screen of a pen-based computer system characterized by the steps of: (a) determining that a selection gesture has been made on the screen of the pen-based computer by a stylus; (b) detecting a path made by the stylus across at least a portion of an object depicted on the screen; (c) displaying a line image on the screen along the path; (d) determining a selection of at least a portion of the object as indicated by the path; and (e) displaying selection indicia on the screen representing the selection. The step of displaying the selection indicia can occur concurrently with or after the complete path is made by the stylus on the object. Preferably, the line image is removed after the step of displaying the selection indicia.

Abstract: A rendering device for providing 3-D graphics rendering in a computer system. A hardware scanline rendering approach is utilized. Using a hardware scanline rendering approach the bandwidth requirements between a system frame buffer and the rendering device are minimized. The minimization of bandwidth requirement allows for the rendering device to be used with existing computer system designs while keeping design changes at a minimum. The result is that for a given desired performance of a combined computer system and rendering device, the cost of both the computer system without the rendering device, and the cost of the rendering device itself may be reduced. The rendering device is generally comprised of a bus attachment for coupling to the system bus of the computer system; a scanline rendering device and a scanout device for transferring the scanline of shaded pixel values to the system frame buffer.

Abstract: A method of implementing a multicast routing protocol in routers is provided to manage the assignment of multicast transport addresses and to forward data from a single transmitting endpoint to multiple receiving endpoints. This method in conjunction with a method for implementing the multicast routing protocol as a transport protocol layer service for endpoints provides an internet wide multicast transport service. The multicast transport service provides the capability of transmitting data from a single source to multiple receivers on interconnected networks efficiently and without having to send duplicate copies of the data on any single network. Routers and endpoints transmit and receive multicast packets in a manner which is independent of the network layer datagram protocols used by the multicast transport service.

Abstract: An independent windowing system that eliminates gridding comprises a method for performing windowing operations directly in device space for a graphics system which specifies all drawings in coordinate space. The re-sizing effects of rendering an object in different places on the coordinate grid are absorbed in the window borders, allowing the window contents to be moved without re-drawing them. The window can be moved without re-drawing it even when the resolution of the device the window is displayed in differs from the source resolution of the rendering system. Furthermore, window contents are drawn relative to the coordinate of the top left of the window to provide each window with its own device grid independent of the window position on the device.

Abstract: Audio signal connection and conditioning circuitry employs a resistive drop across the ground input for the signal source to generate a common mode voltage on both input lines. A differential amplifier subtracts the generated common mode voltage on the ground line from the common mode voltage on the source input line, leaving only the source voltage as an output. The differential amplifier output is generated with respect to a positive, stable voltage reference instead of a floating ground.

Abstract: A light pipe for a personal computer transmits light from a lamp to an indicator window formed in the computer housing. The pipe is formed of a block of light-transmitting plastic material and includes a plurality of sections oriented perpendicular to one another. Light rays are reflected from each section to the next off an inclined light reflecting surface. One of the sections is of square cross section, and the next section is of non-square cross section. The light reflecting surface disposed at a junction between those two sections is of stepped configuration to form a series of sub-faces, each of which is inclined at a 45 degree angle relative to oncoming light rays for reflecting light across the entire cross section of the non-square section.

Abstract: A method and apparatus for determining and displaying or preventing a collision between two objects. Certain characteristics of these two objects such as their sizes, orientations, and velocities, are inputted. Based upon these characteristics, a collision contour is generated about the first object. If either or both object(s) had been moved, the collision contour is generated based on a velocity outline to account for the velocity effects. These two objects have collided if the second object's centerpoint is included in the collision contour. Otherwise, the two objects have not collided. The result is then portrayed on a graphics display device.

Abstract: Circuit arrangements and methods are disclosed for upgrading an 040-based personal computer system using an optional, peripheral add-in card. In one embodiment, the present invention comprises a PowerPC-based microprocessor, such as the MPC601, having one megabyte of on-board direct mapped level 2 external cache memory arranged as tag and data blocks. The PowerPC-based board is inserted into a processor-direct data path sharing the data and address bus with the 040 microprocessor. System random access memory (RAM), I/O, and other functional blocks are present on the main board comprising the 040-based computer. The MPC601 is coupled via address and data buses to the tag cache, a bus translation unit (BTU), a read only memory (ROM) storing the operating system code for the PowerPC microprocessor, the data cache, a dual frequency clock buffer, and other interface components such as a processor-direct data path including address and data latches.

Abstract: A low-cost yet high-performance, moderate bandwidth (up to 2 Mbps) global telecommunications interface to new and existing computers allows high-performance, low-cost telecommunications platforms to support global fax, data, voice, and other data streams in an intuitive way. The telecommunications interface provides a very low-cost solution to international connectivity for a broad class of existing computers while providing high-performance wide-area data transfer. Convenient and reliable global communications over the phone line may thus be achieved. From a rudimentary viewpoint, the telecommunications interface provides for an elegant, economical implementation of a fax/data modem. The telecommunications interface provides both a time-division multiplexed interface mode for constant bit rate communications and a packetized interface mode for variable bit rate communications. Multiple streams of digital and/or analog-derived data may be handled simultaneously.

Abstract: A computer system, including a display screen and a direct input device such as a mouse, with a direct manipulation interface, through which the user can not only cause the computer to perform a predefined task by selectively indicating a symbol representing the task but also edit such symbols and their attributes by causing handle-like figures to appear on the screen near the symbol to be edited. The system is operable in two modes. One is a use mode for having a predefined task carried out and no handle-like figures are shown. The other is an edit-and-use mode wherein the user can cause the handle-like figures to appear or disappear but can also carry out every task that can be carried out in the use mode regardless of whether or not these figures are being displayed.