Abstract: A configurable RAM interface connecting a bus to RAM is adapted to receiving large multiword variable length tokens at a high data arrival rate, using a swing buffer and a buffer manager. An address source provides complete addresses to the interface. The buffer manager has a state machine which transitions among a plurality of states, maintaining status information about the buffers, allocating the buffers for reference by a write address generator, clearing the buffers for occupation by subsequently arriving data, and maintaining status information concerning the buffers. The buffer manager also examines tokens of received data in order to update the status of the arrival buffer.

Abstract: The invention provides a single chip implementation of a digital receiver for multicarrier signals that are transmitted by orthogonal frequency division multiplexing. Improved channel estimation and correction circuitry are provided. The receiver has highly accurate sampling rate control and frequency control circuitry. BCH decoding of tps data carriers is achieved with minimal resources with an arrangement that includes a small Galois field multiplier. An improved FFT window synchronization circuit is coupled to the resampling circuit for locating the boundary of the guard interval transmitted with the active frame of the signal. A real-time pipelined FFT processor is operationally associated with the FFT window synchronization circuit and operates with reduced memory requirements.

Abstract: An apparatus for recording data includes a source of digital data arranged into data words having a given number of bits and a converter that converts the data words to code words having one more bit than the given number using a group code recording format. The code words include a binary signal having first and second binary values at a given clock interval determined by a bit rate of the code words. The apparatus also includes a storage disk having a recording surface, a drive member for rotatably driving the disk, a laser having a focused beam, and a control assembly for directing the laser at the recording surface so that the beam accesses one of a plurality of concentric tracks on the recording surface. A circuit assembly provides a driving signal utilized for generating energizing pulses having a duration less than the clock interval when the binary signal has the first binary value.

Abstract: A multi-standard video decompression apparatus has a plurality of stages interconnected by a two-wire interface arranged as a pipeline processing machine. Control tokens and DATA Tokens pass over the single two-wire interface for carrying both control and data in token format. A token decode circuit is positioned in certain of the stages for recognizing certain of the tokens as control tokens pertinent to that stage and for passing unrecognized control tokens along the pipeline. Reconfiguration processing circuits are positioned in selected stages and are responsive to a recognized control token for reconfiguring such stage to handle an identified DATA Token. A wide variety of unique supporting subsystem circuitry and processing techniques are disclosed for implementing the system.

Abstract: A method for converting frame data at a slower rate into field data at a faster rate in a video decoder comprises determining a basic field repetition rate such that a field is repeated an integer number of times in a frame period, calculating a ratio differential of the repetition rate by subtracting from the speed-up ratio of the faster to the slower rate, the ratio of the fields per frame period to the slower rate, comparing the ratio differential with the differential of the field repetition rate and adding or subtracting extra fields when the two are substantially at variance.

Abstract: A method for moving an optical head from an initial track to a target track on a storage medium having data arranged in tracks thereon. The method includes determining a track crossing number indicating a number of tracks between the initial track and the target track, moving the optical head from the initial track toward the target track, and measuring a reflectivity level of light from the medium. The method continues with deriving a tracking error signal responsive to the reflectivity level. A waveform of the tracking error signal has zero crossings corresponding to the optical head crossing one of the tracks. The method may further include incrementing a track count number for each the zero crossing, and passing the reflectivity level through a high pass filter to obtain a data indicator signal. In this embodiment, a waveform of the data indicator signal has indicator points corresponding to the zero crossings.

Abstract: An apparatus and method is disclosed for focus control of a beam of radiant energy, wherein a detector of the beam has first and second outputs responsive to a position of the beam. A circuit is coupled to the outputs of the detector for producing an error signal representing a displacement of the focus from a predetermined position, wherein the error signal has a periodic characteristic relative to the displacement. A servo responsive to the error signal restores the displaced beam to the predetermined position. A local feedback loop is coupled to the outputs of the detector, and includes first and second periodic function generators, each responsive to the error signal. The second periodic function generator has an output that differs from an output of the first periodic function generator by a phase angle, preferably 90 degrees. A first multiplier multiplies the first output of the detector by the output of the first periodic function generator.

Abstract: An apparatus for the ergonomic positioning of a computer pointing device comprising a generally planar support member, an armrest attachment member, an adjustable coupling for attaching the support member to the armrest attachment member, and a plurality of straps for mounting the armrest attachment member onto the armrest of a chair. The adjustable coupling provides for rotational positioning of the support member around an axis parallel to the user's line of sight to the monitor, tilt positioning of the support member around an axis perpendicular to the user's axial line of sight to the monitor, and lateral positioning of the support member relative to the armrest attachment member. The armrest attachment member has a generally U-shaped cross-section adapted to fit over the existing armrest of a chair, and the attachment straps, which have Velcro™ fasteners or the like, fasten the armrest attachment member securely onto the armrest.

Abstract: An optical drive system includes an optical assembly, a light source, a lens positioned to direct light between the optical assembly and an information storage medium or disc, and an actuator suspending the lens. A photodetector is disposed in a path of returning light to measure light received from the medium. A monitoring circuit is provided to monitor a Quad Sum signal associated with return light. A first servomotor is employed to move the lens in a tracking direction and to move the lens during focus capture while system circuitry searches for a maximum Quad Sum signal. A second servomotor is employed to move the lens in a focusing direction. A first electronic circuit is provided to control the first and second servomotors.

Abstract: An improved system for recording and playing back digital information in a special pulse-length modulation format on a disc-shaped record. The digital information is stored in a succession of alternating marks and spaces, both having lengths that are discretely variable in accordance with a succession of multi-bit binary code blocks.

Abstract: A video record medium, such as a record disc, for recording a composite video and audio signal suitable for stop-motion playback, with accompanying audio. Discrete segments of analog audio signal are digitized and compressed in time and recorded on alternate tracks on the disc, and corresponding frames of a video signal are recorded on the tracks located therebetween. During playback of the disc, a selected audio track is scanned initially and the digital audio data recovered therefrom is entered into a memory device, after which the track for recording the corresponding video frame is scanned in a repeated fashion, to produce a stop-motion display of the frame, while the stored audio data is extracted from the memory device and converted back to an analog format, for simultaneous playback at its original speed.

Abstract: A method and system for automatically collecting and for analyzing information about time and work performed on a computer includes a hardware abstraction layer for monitoring activity on various user input devices. The system also includes the following elements: a data collector for monitoring certain portions of a user's computer activity and for logging into a log file those certain portions of a user's computer activity; a data analyzer for determining by following user-defined rules showing which portions of those certain portions of a user's computer activity constitutes continuous work activities, and how this work should be categorized by project and task with project; and an external interface for building the rules defining work. The data collector includes a resident module, such as a TSR (terminate-and-stay-resident) module, which extends the file system of the computer so that detailed records are kept of file activities.

Abstract: A video record medium, such as a record disc, for recording a composite video and audio signal suitable for stop-motion playback, with accompanying audio. Discrete segments of analog audio signal are digitized and compressed in time and recorded on alternate tracks on the disc, and corresponding frames of a video signal are recorded on the tracks located therebetween. During playback of the disc, a selected audio track is scanned initially and the digital audio data recovered therefrom is entered into a memory device, after which the track for recording the corresponding video frame is scanned in a repeated fashion, to produce a stop-motion display of the frame, while the stored audio data is extracted from the memory device and converted back to an analog format, for simultaneous playback at its original speed.

Abstract: A video record medium, such as a record disc, for recording a composite video and audio signal suitable for stop-motion playback, with accompanying audio. Discrete segments of analog audio signal are digitized and compressed in time and recorded on alternate tracks on the disc, and corresponding frames of a video signal are recorded on the tracks located therebetween. During playback of the disc, a selected audio track is scanned initially and the digital audio data recovered therefrom is entered into a memory device, after which the track for recording the corresponding video frame is scanned in a repeated fashion, to produce a stop-motion display of the frame, while the stored audio data is extracted from the memory device and converted back to an analog format, for simultaneous playback at its original speed.

Abstract: An technique is disclosed for focus control of a beam of radiant energy, wherein a detector of the beam has first and second outputs responsive to a position of the beam. A circuit is coupled to the outputs of the detector for producing an error signal representing a displacement of the focus from a predetermined position, wherein the error signal has a periodic characteristic relative to the displacement. A servo responsive to the error signal restores the displaced beam to the predetermined position. A local feedback loop is coupled to the outputs of the detector, and includes first and second periodic function generators, each responsive to the error signal. The second periodic function generator has an output that differs from an output of the first periodic function generator by a phase angle, preferably 90 degrees. A first multiplier multiplies the first output of the detector by the output of the first periodic function generator.

Abstract: A hairpin which gives hair the appearance of greater volume and thickness by using a support member which protrudes from the side of the lower leg of the hairpin at an acute angle and which extends substantially parallel to the legs of the hairpin. Hairs being held between the legs of the hairpin are elevated by the support member to a position above the upper leg of the pin and away from the scalp, thus giving the appearance of fuller, thicker hair.

Abstract: A device which monitors the head turn movement of a golfer during a golf swing. It gives the golfer instantaneous feedback by informing him whether his head turned prior to or after the golf club struck the ball. This feedback is done in the form of a digital LCD display of the time difference in milliseconds and also in the form of audible beeps. From this information, the golfer can make the necessary adjustments and corrections in the execution of his swing. The device is compact and portable. It is placed near the golf ball such that the ball lies directly between the golfer and the device. After the information is displayed, the device automatically resets and readies itself to monitor the next golf swing.