Abstract: The invention provides a RAM interface for connecting a bus to RAM wherein a separate address generator generates the addresses the RAM interface needs to address the RAM. The interface utilizes a plurality of swing buffers, and has a control module for coordinating accesses thereto, which is connected to the address generator by a specialized two-wire interface. The address generator and the source of data are clocked asynchronously and at different clock rates.

Abstract: A CMOS integrated signal processing system for a sampling receiver includes a timing recovery circuit, wherein an on-chip numerically controlled oscillator is operative at periods T that are initially equal to the nominal baud rate of the signals controls a sinc interpolator receiving samples at the sampling rate. A loop filter is coupled to the sinc interpolator and to the numerically controlled oscillator. The arrangement is capable of handling various symbol rates. The system includes a circuit for carrier recovery having a second on-chip numerically controlled oscillator, a digital derotation circuit responsive to the second numerically controlled oscillator, accepting an in phase component and a quadrature component of the sampled signals. An adaptive phase error estimation circuit is coupled in a feedback loop.

Abstract: The mechanism for loading and unloading a disk cartridge uses two sliders (one on each side of a base plate), which move in opposite directions under the influence of a tiller. Each slider has a slot to receive one of the two lifting pins provided on the cartridge receiver. The movement of the sliders drives the lifting pins along the slots, thereby raising or lowering the cartridge receiver depending upon the direction of rotation of the tiller. The sliding motion of the lifting pins engaged in the S-shaped slots thus unloads a disk from or, alternatively, loads the disk onto the drive spindle. As the lifting pins travel along their respective slots, the lifting and lowering of the disk is accomplished in such a manner that the disk hub is peeled from the spindle magnet rather than being lifted vertically off the spindle. This reduces the peak force required to break the magnetic clamp force between the spindle magnet and the disk hub.

Abstract: An apparatus for controlling a magnetic field strength of a bias coil at a focal point of a lens during recording on a medium. The apparatus includes a first controller for determining a distance between the focal point of a lens and a reference point on the recording media. A source generates a stray magnetic field having a stray field strength at the focal point. A second controller calculates a digital signal which is a function of the distance and the stray field strength. A digital-to-analog converter converts the digital signal to a driver voltage and passes the driver voltage to a current driver, which drives the bias coil. The magnetic field strength of the bias coil is thereby controlled at a predetermined value.

Abstract: There is disclosed a method for moving an optical head from an initial track to a target track on a storage medium. The total number of tracks to be crossed is determined, and the optical head is moved toward the target track. A reflectivity level of light from the storage medium is measured, and a tracking error signal is derived from the reflectivity level. The tracking error signal has both true and false indicators of track crossings. A data indicator signal is derived from the reflectivity level, having indicator points corresponding to the false indicators of track crossings. A track count number is incremented for each true indicator of a track crossing, and the optical head is stopped when the track count number equals the total number of tracks to be crossed. Another method is disclosed whereby a track count signal is generated from the tracking error signal and the data indicator signal.

Abstract: An integrated digital communication system utilizing multilevel vestigial sideband transmission is provided. The communication system receives a multi-level pulse-amplitude modulated digital signal from a limited bandwidth channel. The system includes processing stages which demodulate, sample and filter the incoming signal prior to recovery of the digital data. Other stages recover the timing and lock on to the frequency and phase of the transmitted signal, as well as provide for automatic gain control. An adaptive equalizer, error correction circuitry, and an output interface recover the digital data and provide for transfer to other devices.

Abstract: A bias coil assembly for use in combination with a magnetomotive generator such as employed in a magneto-optical disc drive. The assembly includes a return yoke having a body portion and a tip having a predetermined thickness and extending beyond the body portion. A winding for receiving electric current is wound around the body portion of the yoke so that the winding is contained below the tip. A first plate is disposed on the winding and includes at least one heat-radiating finger extending substantially around the winding without increasing the vertical height of the assembly. A second plate is disposed on the winding in a magnetic circuit with the first plate and the return yoke so that when the winding is connected to a source of power, the tip receives lines of magnetic flux that are channeled through the body portion while the at least one flange radiates thermal energy thereby produced.

Abstract: A method and apparatus for manufacturing information storage devices is described herein. Two embodiments of the invention are disclosed. In particular, the invention includes, but is not limited to, a bearing insertion device, a lens insertion device, a coarse coil gluing tool, a spring gluing tool, a device for gluing pole pieces, a pentaprism insertion and inspection tool, a constants and transfers test, an optics module alignment device, wedge, microprism and beamsplitter insertion devices, a read channel alignment test, a mass balance attachment invention, a position sensor alignment tool, an invention for the attachment of focus and radial coils, a quality control test for test an optical storage device prior to insertion of the objective lens, and a servo system test. The invention described herein is designed to manufacture information storage devices with increased quality and efficiency.

Abstract: An apparatus and method for retrieving densely stored data from various types of magnetic media. A medium is scanned to provide an input signal. The input signal is conditioned through differentiation, equalization and partial integration. Positive and negative signal peak detectors are connected to the conditioned signal, and a threshold signal is generating corresponding to an average or midpoint of the measured positive and negative signal peaks. An output signal is generated by comparing the conditioned signal and the threshold signal. The DC component of the input signal is accounted for by feeding back the output signal and adjusting the threshold signal based on the duty cycle of the output signal.

Abstract: The mechanism for loading and unloading a disk cartridge uses two sliders (one on each side of a base plate), which move in opposite directions under the influence of a tiller. Each slider has a slot to receive one of the two lifting pins provided on the cartridge receiver. The movement of the sliders drives the lifting pins along the slots, thereby raising or lowering the cartridge receiver depending upon the direction of rotation of the tiller. The sliding motion of the lifting pins engaged in the S-shaped slots thus unloads a disk from or, alternatively, loads the disk onto the drive spindle. As the lifting pins travel along their respective slots, the lifting and lowering of the disk is accomplished in such a manner that the disk hub is peeled from the spindle magnet rather than being lifted vertically off the spindle. This reduces the peak force required to break the magnetic clamp force between the spindle magnet and the disk hub.

Abstract: An MPEG video decompression method and apparatus utilizing 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, including memory addressing, transforming data using a common processing block, time synchronization, asynchronous swing buffering, storing of video information, a parallel Huffman decoder, and the like.

Abstract: The present invention allows the light beam of an optical disc storage device to radially move between different information tracks of an optical disc while the storage device tracking servo loop remains in a continuous closed loop mode of operation. The invention operates to radially move a light beam from one information track to another during a closed loop mode of operation by activating two control signals introduced into the closed tracking servo loop to create a phantom track center that radially moves across the optical disc. Because the tracking servo loop is in a closed loop mode of operation, the tracking servo operates to keep the light beam centered on the point that the tracking servo considers to be the center of an information track; in this case the phantom track center. Therefore, the tracking servo causes the light beam to radially move across the disc in a closed loop mode of operation by keeping the light beam centered on the moving phantom track center.

Abstract: A flexible strip test cable is disclosed having an elongated flexible strip cable, a series of strip traces disposed lengthwise on the flexible strip cable and having electrical strip contacts near one end of the flexible strip cable, an extension cable integral with the flexible strip cable and having a width at one end greater than the width of the flexible strip cable, and a series of test traces on the extension cable having electrical test contacts near the end of the extension cable remote from the flexible strip cable. Each of the test traces is electrically connected to one of the strip traces, and the minimum distance between two test contacts is greater than the minimum distance between two strip contacts. The flexible strip test cable may have a tooling guide for aligning a cutting tool with the end of the flexible strip cable which is connected to the extension cable.

Abstract: A method for addressing memory uses a word with a fixed width, having a fixed number of bits, and having a width defining field and address field. The procedure is adapted to addressing variable width data. In one embodiment memory can be addressed using a fixed width word having a fixed number of bits, and having both a substitution field and an address field.

Abstract: An integrated digital communication system utilizing multilevel vestigial sideband transmission is provided. The communication system receives a multi-level pulse-amplitude modulated digital signal from a limited bandwidth channel. The system includes processing stages which demodulate, sample and filter the incoming signal prior to recovery of the digital data. Other stages recover the timing and lock on to the frequency and phase of the transmitted signal, as well as provide for automatic gain control. An adaptive equalizer, error correction circuitry, and an output interface recover the digital data and provide for transfer to other devices.

Abstract: This invention provides a method to control the buffering of encoded video data organized as frames or fields. This method involves determining the picture number of each incoming decoded frame, determining the expected presentation number at any time and marking any buffer as ready when its picture number is on or after the presentation number.

Abstract: An apparatus is disclosed for 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 beam 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: The mechanism for loading and unloading a disk cartridge uses two sliders (one on each side of a base plate), which move in opposite directions under the influence of a tiller. Each slider has a slot to receive one of the two lifting pins provided on the cartridge receiver. The movement of the sliders drives the lifting pins along the slots, thereby raising or lowering the cartridge receiver depending upon the direction of rotation of the tiller. The sliding motion of the lifting pins engaged in the S-shaped slots thus unloads a disk from or, alternatively, loads the disk onto the drive spindle. As the lifting pins travel along their respective slots, the lifting and lowering of the disk is accomplished in such a manner that the disk hub is peeled from the spindle magnet rather than being lifted vertically off the spindle. This reduces the peak force required to break the magnetic clamp force between the spindle magnet and the disk hub.

Abstract: A first write encoder encodes digital data in a first, high-density format. A second write encoder encodes digital data in a second, low-density (i.e., ANSI) format. A first read decoder decodes digital data from the first format. A second read decoder decodes digital data from the second format. A disk drive receives a replaceable 90 millimeter optical disk. A read/write head reads encoded data from and writes encoded data to a 90 millimeter optical disk received by the drive. In a first mode, the first write encoder is connected between a source of digital data and the read/write head, and the first read decoder is connected between the read/write head and the utilizing apparatus. In a second mode, the second write encoder is connected between the source and the read/write head, and the second read decoder is connected between the read/write head and the utilizing apparatus.

Abstract: A method for moving a carriage assembly from an initial position to a target position relative to a storage medium rotating at a circumferential velocity. The method includes the steps of determining a first radial distance between the initial position and a center of the storage medium, determining a second radial distance between the target position and the center of the storage medium, determining a circumferential distance between the initial position and the target position, determining an initial circumferential velocity of the storage medium, calculating a velocity trajectory relative to the first radial distance, the second radial distance, the circumferential distance, and the initial circumferential velocity, and moving the carriage assembly from the initial position to the target position substantially at the velocity trajectory. The velocity trajectory is calculated such that the carriage assembly will arrive radially and circumferentially at the target position at substantially the same time.