Abstract: A networked computer system for storing and presenting multimedia data distributes that data among multiple storage devices of the system. The system includes a plurality of computers, each of which supports at least one viewing station. Each viewing station has access to any file on any of the storage devices and can retrieve and display any file on demand. To provide an efficient system and, at the same time, reduce the probability that the viewing of multimedia data may be interrupted, the system allocates resources, prioritizes access to files, and buffers data prior to the data's delivery to video adapters.

Abstract: A networked computer system for storing and presenting multimedia data distributes that data among multiple storage devices of the system. The system includes a plurality of computers, each of which supports at least one viewing station. Each viewing station has access to any file on any of the storage devices and can retrieve and display any file on demand. To provide an efficient system and, at the same time, reduce the probability that the viewing of multimedia data may be interrupted, the system allocates resources, prioritizes access to files, and buffers data prior to the data's delivery to video adapters.

Abstract: Digitized audio information is compressed by retrieving a first audio sample from a digitized audio signal and storing it in its entire, uncompressed, form. The next audio sample is then retrieved and a signed difference between the first audio sample value and the next audio sample value is computed. If this difference value can be represented in fewer data segments than would be required to represent the next audio sample, the difference value is stored, rather than the value of the next sample, otherwise the next sample is stored. The invention proceeds in this fashion until the entire PCM audio signal is compressed and stored. The compressed data stream is decompressed to generate an output data stream by retrieving a stored sample and examining it to ascertain whether it is a difference value or a flag which indicates that the following data represents a coded amplitude value.

Abstract: A networked computer system for storing and presenting multimedia data distributes that data among multiple storage devices of the system. The system includes a plurality of computers, each of which supports at least one viewing station. Each viewing station has access to any file on any of the storage devices and can retrieve and display any file on demand. To provide an efficient system and, at the same time, reduce the probability that the viewing of multimedia data may be interrupted, the system allocates resources, prioritizes access to files, and buffers data prior to the data's delivery to video adapters.

Abstract: A novel virtual desktop system organizes open applications of a computer into groups of programs that perform common functions or tasks. The groups of programs are called Desktops and the virtual desktop system provides a Desktop Manager for assigning ranges of display screen coordinates to these Desktops, and then assigning open applications to them. Specifically, the Desktop Manager is a system software program that contains a plurality of Desktop groups and that provides a user interface for managing the display of selected open applications assigned to the Desktops. These selected open applications are displayed in application windows on a display screen of the computer when switching between Desktops in the virtual desktop system.

Abstract: Digitized audio information is compressed by retrieving a first audio sample from a digitized audio signal and storing it in its entire, uncompressed, form. The next audio sample is then retrieved and a signed difference between the first audio sample value and the next audio sample value is computed. If this difference value can be represented in fewer data segments than would be required to represent the next audio sample, the difference value is stored, rather than the value of the next sample, otherwise the next sample is stored. The invention proceeds in this fashion until the entire PCM audio signal is compressed and stored. The compressed data stream is decompressed to generate an output data stream by retrieving a stored sample and examining it to ascertain whether it is a difference value or a flag which indicates that the following data represents a coded amplitude value.

Abstract: A graphical user interface, executable on a computer system, includes a first user-selectable icon, displayable on the computer system and representing an object having desired properties within the computer system. A second user-selectable icon, also displayable on the computer system, appears visually distinguishable from the first icon and likewise represents the same object. The second icon has associated therewith at least one of user-selectable command, which enables manipulation of the properties of the object upon selection thereof. The second icon may be located remotely from the first icon on the graphical user interface to provide for convenient manipulation of the object properties without having to access the first icon repeatedly.

Abstract: A data processing system has a virtual memory manager for swapping information between primary memory (such as RAM) and secondary memory (such as a fixed disk). The virtual memory manager employs an ager to determine which information in RAM is eligible for swapping out to the fixed disk. The ager links eligible information to an idle list. The idle list has minimum and maximum sizes. The ager has execution priorities that depend on the minimum and maximum sizes of the idle list. When the idle list is at the minimum size, the ager runs at a higher priority in order to identify information that can be swapped out. When the idle list is at or near the maximum size, the ager runs at a lower priority. The size of the idle list is dynamically adjusted to account for any information that is reclaimed from the idle list and also to account for any changes in the amount of swappable information (which is in non-resident primary memory).

Abstract: A power management architecture in a data processing system comprising physical devices having at least one state, each state has corresponding power value, and where a system state is defined as the set of all current states of the physical devices. Power objects and thermal objects, each corresponding to a physical device, contain information about the power requirements and thermal characteristics of each possible state for that physical device. The power and thermal objects also describe the allowed state transitions from each possible state to another state, and the power requirements and thermal characteristics of all possible state transitions. Also communicated is the current state of each physical device. Event means generate signals indicating the occurrence of an event in the system. A policy module contains rules, implementing the power management, that direct an action, the rules being a function of events and of power object information.

Abstract: A synchronization process in an application program records audio fields with video synchronization counts, and plays back the audio and video fields in synchronism by tracking the video fields against the video sync counts in the audio fields. The video sync counts correspond to the number of video field processed when the audio field is processed. During recording of audio and video fields for the multimedia presentation, the video fields are counted. The video field count is appended to and recorded with each audio field. During playback, the system compares the count of video fields displayed against the video field count appended to the audio field being presented. If the counts are different, the system either skips video fields, or repeats video fields to bring the video fields into synchronism with the audio fields.

Abstract: An apparatus and method for transmitting X.25 communications over the D-channel of an ISDN link. This is achieved by terminal adapters connected between an X.25 terminal and an ISDN connection which contain converters to convert X.25 LAPB frames into LAPD frames and vice versa. The conversion process involves directly copying fields from the incoming LAPB frame into a LAPD frame with the minimum amount of verification. Essentially the only checking performed is to examine the number of octets in each field of the incoming frame to ensure that the conversion process itself does not fall down.

Abstract: An digital video image processing system employs codes of various lengths to encode the luminance information within the digital video images. The inventive method and apparatus divides a video image into non-overlapping regions containing a plurality of pixels with luminance values. Within each region, the method computes the total luminance variation across the region, the direction of greatest luminance change within the region, the base, or lowest, luminance value within the region and the location and type of luminance transition within the region. Depending on the variation of the luminance values within a region and on the quality desired in the decoded image, the computed information is used to encode the luminance values in short, medium, or long codes. The luminance codes may be predetermined and unchanging or they may vary from image to image or within given images.

Abstract: A system and method for providing debugging of a data processing system having a plurality of resources, a keyboard and a multitasking operating system including a plurality of protection domains and a keyboard device driver which executes in a protection domain having maximum access privileges to system resources. A debugging module in the keyboard device driver is provided. Responsive to user selection through a predetermined key stoke sequence, the debugging module may be invoked. Utilizing the debugging module, various system registers and memory locations are accessed and the contents placed in the keyboard input buffer for display on a computer monitor.

Abstract: The foregoing has described a method of providing a template in a computer system graphical user interface by supplying a visual cue which readily identifies the template and by supplying a direct template manipulation feature to increase the ease by which users can create objects. The template visual cue is provided to distinguish an instance of an object from its template form. Any object of any class which contains data and settings can be made into a template by turning on its template setting. When an object becomes a template, the icon which represents it is immediately altered. In particular, its icon becomes miniaturized or scaled down and superimposed on top of a normal size icon which resembles a pad of sheets of paper. This metaphor or visual cue is used to symbolize a stack of objects, of which new objects can be peeled off the top of the stack. With a drag and drop mouse action, a new object can be picked off of a template stack and dropped into any folder.

Abstract: An image-compression/decompression system employs a variable spatial-frequency encoder to encode the chrominance information contained within a video image. The system divides the video image into non-overlapping regions and partitions each region into sub-regions. Within each region, the system computes a weighted average of the chrominance values in each sub-region, and compares the weighted average value associated with each sub-region to the weighted average values associated with the other sub-regions within the region. If differences between the average values are less than a predetermined threshold amount, the system assigns a single chrominance encoded value to the entire region. If, on the other hand, the differences between the weighted average values is more than the predetermined threshold amount, the system assigns individual chrominance values to each of the sub-regions.

Abstract: A computer system and method of operation thereof are provided including an improved graphical user interface (GUI). A conditional cascading menuing method and apparatus which shield novice users from being overwhelmed by advanced operations in the desktop which appears on the user's computer screen. The conditional cascading feature provides the user with the ability to select a basic function or action from a main menu on the desktop, in which case the default behavior of the function will be performed, or to conditionally display, by pressing a mini push-button next to the main menu item text, a submenu of all forms of function or action. The default submenu behavior or item is indicated by a checkmark adjacent the default item in the submenu. Each time the user selects a submenu item which is different from the default submenu item, the presently selected submenu item becomes the default item or behavior.

Abstract: A video display adapter control system is provided for utilization in a data processing system which includes a processor, data storage, a video display device and one of multiple selected video display adapter cards. A text data file is generated, utilizing either a utility program, or manufacturer provided information, which specifies video adapter information for a specific video adapter card including: an identification of the particular video adapter; port addresses and indices; commands necessary to lock and unlock extended video registers; data which describes video mode resolutions and colors; and the necessary commands and data to enable selected video modes to be set and stored. A video display device driver is then provided which is capable of accessing and parsing the text data files and which creates multiple command structures in response thereto.

Abstract: Disclosed is a method of accessing at least a first of a plurality of object owned windows simultaneously open in a graphic user interface on a computer system. For each object on a computer system, an object list is maintained. The object list includes all opened windows owned by the objects. User inputs to the computer system are monitored for a user request for a window list. Responsive to a user request for the window list, each object list is retrieved and, for objects lists having a single opened window, a window entry to the window list is listed. For object lists having a plurality of opened windows, an object entry and a plurality of window entries are added to the window list. The window list is then displayed. Window names include an owning object identifier and a description of the window.

Abstract: A method and apparatus for the enhancing efficiency of a data processing system which includes a host microprocessor, a system memory, and a graphics adapter for producing an enhanced graphics display. The graphics adapter is coupled to the data processing system by a bus and includes a video memory and an adapter microprocessor, wherein the adapter microprocessor is less powerful than the host microprocessor in the data processing system. The method and apparatus of the present invention includes the establishment of a stage buffer from a portion of the system memory with the stage buffer, including at least two buffer sections. A first portion of data is transferred from the system memory into a first buffer section.

Abstract: A color video system includes a palette data register for storing triplets of color data that control the colors of pixels. The triplets are stored at indexed locations accessed by an autoincrementing index register. When an application is switched from the foreground, one or more palette data register accesses are made until the index register is incremented, and a triplet pointer is set in accordance with the number of accesses, to point to the triplet member that was being accessed when the foreground switch occurred. When the application is switched back into the foreground, the value stored in the triplet pointer is used to point to the triplet member being accessed when the foreground switch occurred.