Abstract: A computer subsystem for presenting both video and graphic information on a computer output display in a computer system having a central processing unit and a frame buffer including apparatus for providing a video input signal representing full frame of video interlaced data, apparatus for selecting a rectangular portion of the video data to be presented, apparatus for converting the selected portion of the video signal into a stream of digitized pixel signals, apparatus for designating each such pixel of video information which is to be written to the frame buffer, and apparatus for addressing each of such pixels for storage at selected points of the frame buffer.

Abstract: A circuit which includes apparatus for determining for at each node of a multi-node interconnect the highest priority data present for transfer to that node, apparatus for storing information indicating the last node from which a transfer of data occurred at each priority level, apparatus for selecting for each priority level of data available at the node the last node from which a transfer of data occurred at each priority level, apparatus for weighting data at each priority level depending on the data last chosen at that level of priority, and means for selecting from all of the data available at each node the data having both the highest priority and having been chosen least recently at that priority levels of data at that node.

Abstract: A computer having a video circuit which is configured by a monitor identification signal is described. The self-configuring circuit permits connection to a variety of monitor types without the need for a separate video card or other dedicated circuitry compatible with the specific monitor type. The computer automatically senses the type of the monitor to which it is coupled, then configures its internal circuitry to provide compatible video signals to the monitor. The invented computer includes a central processing unit (CPU) for executing a program to provide video data for display on the monitor. The data is stored in the computer in a random-access memory (RAM). The monitor provides an identification signal to the video circuit which then provides both the appropriate video timing signals and the video data to the monitor for display thereon. The identification signal is used to configure the video circuitry in accordance with the requirements of the monitor.

Abstract: A circuit for producing output signals which indicate a fraction of a series of input signals including apparatus for furnishing a first value equivalent to the value of a numerator of the fraction, apparatus for furnishing a second value equivalent to the value of the difference between a numerator of the fraction and a denominator of the fraction, apparatus for sequentially subtracting the second value from the first value with each input signal of the series until a result of zero or less is produced, apparatus for sequentially adding the first value to the result with each input signal of the series until a result of greater than zero is produced, and apparatus for utilizing the value of the result to indicate whether each signal of the series of input signals is to be utilized.

Abstract: A power management system for a portable computer is disclosed. The system can determine which one of a plurality of battery packs has been coupled to the system. After determining the type of battery pack, the system recalls from storage the recommended charging pattern for the particular battery pack and begins to charge the battery at the recommended rate. The system's information is used during charging to determine if the battery pack is defective. When the computer is running off the battery pack, the charge counter measures the total amount of charge supplied to the computer and provides this information to the system. When the difference betweem the total amount of charge supplied to the computer and the total charge available from the battery reaches a predefined limit, the system indicates to the computer that a low-power situation exists and that the computer should prepare for a possible loss-of-power event.

Abstract: In a bus adapter coupling a system bus and an I/O bus which operate at different speeds and contain a plurality of devices, a method by which an arbiter in the bus adapter prevents contention for ownership of both buses by a device on either of the buses. The method includes the steps of sampling each of the devices requesting ownership of said buses and asserting a bus grant to one of the devices on one of the buses based on its assigned priority number. The method also includes the step of waiting for the device granted the bus to send an acknowledge signal to display ownership of the buses and for each of the devices not on the bus containing the device granted the bus to see the acknowledge signal before resampling and reasserting a new bus grant to another of the requesting devices.

Abstract: An apparatus for displaying images comprising a display capable of displaying rendered imagery. The apparatus comprises a rangefinder coupled to the display which is capable of determining the distance from a viewer to the display. The apparatus further comprises a means for displaying an image upon the display, the image having a perspective such that the display is a projection plane of a perspective volume. A distance from the projection plane to a center of the projection is proportional to the distance from the display to the viewer, and the distance from the center of the projection to the projection plane is dynamically modifiable depending on the distance detected by the rangefinder. The display may be transparent so that a background scene may be visible with the rendered image superimposed upon it.

Abstract: A method and apparatus for decoding a variable length codeword (VLC) by reading a VLC, the VLC having a maximum length of X bits. The VLC is used as an index into a first table, wherein the first table contains decoded values for all possible VLC's with Y bits not equal to any value in a first set of values. Y is typically less than X and comprises, in the preferred embodiment, the most significant bits of the VLC. If the first Y bits of the VLC are not equal to any value in a first set of values then a second value is returned from the first table. If the first Y bits of the VLC are equal to any value in a first set of values, then a pointer to a second table is returned from the first table. The VLC is used as an index into the second table, and a third value is returned from the second table.

Abstract: An apparatus for optical encoding. An electrical input circuitry is provided for providing a pulsed electrical input signal. A light source circuitry is connected to the pulsed electrical input circuitry for utilizing the pulsed electrical input signal to produce pulses of light. Light collecting and electrical conducting circuitry is provided and synchronized with the light source circuitry. The light collecting and electrical conducting means is positioned in relation to the light source circuitry for receiving and being responsive to light produced by the pulsed light source circuitry. An electrical output signal is produced, indicating such a response. Positionable light interrupting circuitry is provided for opening and closing the optical path of light being transmitted from the light source circuitry to the light collecting and electrical conducting circuitry. The opening and closing affects the electrical output signal, the resulting pulsed electrical output signal for use in encoding.

Abstract: A stochastic priority based scheduler for selecting executable tasks in a computer system is disclosed. The stochastic priority based scheduler selects tasks on the basis of a random number weighted by task priority. Since every task has a nonzero finite probability of being selected, the probability being proportional to the task priority, all tasks, even low priority ones, have a chance of being selected, thus eliminating the lockout problem.

Abstract: The present invention comprises an apparatus and method for transporting print media with wet ink out of a printer without smearing the ink or requiring the user to adjust the margins of the document to avoid the smearing of the ink. The apparatus comprises a platen for holding the print media prior to ejection from the printer, an ejection bar having flexible, resilient fingers for catching the bottom of the print media when flexed and then kicking the paper out of the printer. The ejection bar is actuated by an eccentric cam drive to move it away from the print media when the fingers are traveling toward the bottom edge of the print media, then moving it toward the paper bottom edge to flex the fingers and then upward to eject the paper out of the printer. The upward movement also causes the fingers to spring to an unflexed configuration, thereby kicking the paper out of the printer.

Abstract: A method for clock synchronization for receiving pulse position encoded signals in which a clock signal defines slots or windows of time in which to receive pulse signals. The signal received within a slot is measured to obtain a value representing the amount of signal received within that slot. The values from adjacent slots are compared to determine into which slot the signal most fully fits, and to determine a clock correction value which would change the phase of the clock to make the slots more accurately center on the received pulses. During a time period in which clock adjustment will not affect received pulses, the clock correction value is applied to the clock. In a preferred form, the measurement of pulses, comparison between slots, and clock correction are all performed digitally. A list of energy values is maintained for all slots within a frame, so that the maximum energy value can be selected for assigning a pulse position to a slot within that frame.

Abstract: An arrangement for storing information to be displayed in a plurality of different pixel formats on a bitmapped output display including apparatus for selecting first positions for storage of information in a first pixel format, apparatus for selecting second positions for storage of information in a second pixel format, apparatus for selecting information from first positions of storage for display in the first pixel format, and apparatus for selecting information from second positions of storage for display in the second pixel format.

Abstract: A power consumption reduction method and apparatus for a computer is described. The operating system running on the CPU of the computer determines when the CPU is not actively processing and generates a power-off signal to a control logic circuit. The control logic circuit then disconnects the CPU from the power supply. Pulses sent by a periodic timer or interrupts from input/output units are applied to the control logic circuit to at least periodically issue a power-on signal to the CPU. Power is supplied to the CPU for a given time period at every power-on signal. During this period, the CPU executes miscellaneous housekeeping chores including the polling of disk drives and determines when the CPU should resume normal processing. The control logic circuit also determines, at every power-on signal, whether the CPU is already on or being turned off. The control logic circuit will not issue a reset signal to enable the reset of the CPU if it is already on.

Abstract: A metal frame is fabricated from magnesium alloy and all the main components of the computer, including the logic board, the hard disk drive, the keyboard, the upper and lower halves of the computer's case, and the pivoting display screen are all directly attached to the frame. The frame thus offers a method for constructing a personal computer which will have greatly improved shock resistance, integrated electromagnetic isolation, and structural strength, without increasing the weight of the completed computer in any significant fashion. Additionally, by means of a cooling flange fabricated as part of the frame, the central processing unit of the portable computer is thermally connected to the frame, which then acts as a heat-sink for the central processing unit, greatly improving its reliability.

Abstract: A self-identifying scheme which permits a variety of integrated circuit semiconductor memory modules to inform a host processor as to each individual memory accessing speed or accessing time. Pre-encoded circuits within each memory module generate a coded signal when that module is selected by the host processor. The coded signal identifies the type of memory accessed, permitting the host processor to transfer information at a rate determined by the memory accessed.

Abstract: A video editing system comprising a computer system having a mass storage and a display, a video source, such as a video cassette recorder (VCR), camera, or optical disc player, and a video processor/controller linking the computer to the video source. The computer system functions under the direction of standard operating software and video editing software which provide the user with an interface for controlling both playback and clip editing of video information from the video source. Upon initialization of the editing system, the user is presented with at least a video window for displaying the video information, a control window for regulating playback of the video information, and a clip list window having a number of rows of edit windows organized under begin, end, and clip columns. The user controls playback of video from the video source within the video window through manipulation of standard playback direction and speed indicators.