Abstract: In a pulse width modulated read signal channel for an optical disk drive, a data-transition threshold is maintained for data detection by a threshold tracking circuit that estimates the amplitude centerline data-transition threshold from the most recent maximum and minimum values of the read signal waveform. To improve the accuracy of the response of the centerline estimator, the threshold is increased or decreased based on the phase error at each read signal transition through the data-transition threshold. In addition, defects in the optical recording media are detected, and a defect present signal is used to inhibit the transition phase error input to the centerline estimator. This prevents the estimator from moving the threshold to an incorrect stable level. In addition, the defect present signal boosts the error feedback in the centerline estimator. The estimator then more quickly follows the read signal waveform.

Abstract: This invention relates to "clear pipe" communication networks meaning the nodes and links handle a variety of data frame types depending on their communication protocols such as Token Ring, Ethernet, FDDI or ATM. More particularly, this invention relates to node/link interface adapters at nodes which include switching nodes and end nodes. The adapters identify data frame type and adapt the node/link adapter operative elements to handle the various types of data frames as they travel through the network.The invention identifies the frame type at the source, flags the frame type to the nodes by use of unique SDEL (start delimiter) symbols or codes, uses the SDEL codes as received with the frame at each node to find the destination address in the frame and to adjust the transmission rate for the frame. The transmission rate is adjusted by inserting null non-data symbols in the frame to effectively slow the data rate to the data rate capacity of the protocol.

Abstract: A digital storage system is disclosed in which a flying read/write head is loaded onto the surface of moving storage media with controlled velocity to avoid contact with the surface of the storage media. Head load velocity is detected by measuring the back EMF generated by the head arm actuator. Improved control and accuracy is obtained by breaking up the head arm actuator drive power into a series of pulses and measuring the back EMF induced into the low impedance voice coil of the head arm actuator in between pulses but only after the actuator current has been reduced to substantially zero in order to avoid interference by actuator current induced voltages.

Abstract: A printing system wherein pre-printing commands, print data, and post-printing commands are nested in a data stream, the commands bounding a group of print data pages in the data stream, the group of pages containing one or more page data blocks, and the commands defining one or more operations to be performed relative to the group of pages. Groups of pages are handled in accordance with the commands in the data stream, and the commands are buffered while a print processor processes the group of pages to form printed sheets therefrom.

Abstract: A ring network of workstations interconnected on a single simplex ring is converted to duplex communications on the single ring by placing two transceivers in each workstation and adding a duplex conversion device between each workstation and its ring terminal box. One of the transceivers receives and retransmits signals in a clockwise direction around the ring; the other transceiver receives and retransmits signals in a counter-clockwise direction around the ring. The clockwise and counter-clockwise signals are superimposed on the ring but are isolated at the workstations by the duplex conversion device.

Abstract: An improved storage device, such as a disk drive, for use in an array of drives. Each drive has logic and Exclusive Or calculation means. Data to be written is sent to the target disk drive from the host computer under a new command that instructs the target drive to generate part of the new parity, and may also identify the parity drive. The target device reads the old data from it's media, generates a parity syndrome, stores the new data and then initiates communication with the identified parity drive, instructing the parity drive to read the old parity and generate the new parity information from the parity syndrome and the old parity. The parity drive, after generating the new parity, writes the new parity onto it's media, all without further host or host I/O action.

Abstract: Contained herein are the details of a new drum muffling system for muffling harmonics and overtones of any commercially available drum. The assembly also has the ability to suspend a microphone in proper placement as required by so many modern recording and amplification techniques. The assembly allows for zero interference in the proper seating of the skin on the shell of the drum. The assembly rests against the skin of the drum, and no holes need be drilled in the shell and no part of the system touches the skin of the drum except the actual muffler. The tension against the skin is fully adjustable to muffle overtones of as each application requires.

Abstract: A topology manager external to a communications network manages the network and in particular resolves conflicting topology information about the network by dividing the management of the topology data base into two operations--a collection instance and a resolution layer. A collection instance collects all information that its agent node has about the topology of the network. This topology information is processed by the collection instance to determine for each resource in the network whether the resource is new, reachable or has experienced a reachability change. The resolution layer receives the topology resource information from each collection instance. When a resource is indicated as reachable by a collection instance, that resource is placed on a Reach list as an entry from that collection instance.

Abstract: A system for cascading data switches in a communication node allows for transfer of data among a plurality of adapters (30-i), expanding a moderate low cost switch 31-1 with additional hardware (31-2, 31-3, 31-4) to interconnect more adapters. The data transfers are performed by a plurality of Burst Relaying Cascaders (32-i) which connect the plurality of switches (31-i). A similar interface connect each adapter to the switch. A set of address information is used by the system to route the data from the source adapter to the target adapter, allowing navigation among the intermediate switches. Each interface contains a table where the address of every adapter of the whole system could be constructed dynamically at each communication node configuration.

Abstract: Problems with prior OSI (Open Systems Interconnected) event forwarding discriminators (EFD) are solved in accordance with this invention by creating a new type of EFD, called a notification forwarding discriminator (NFD). An NFD works just like an EFD in that it receives notifications emitted by managed objects and determines what types of notifications should be forwarded. However, the forwarding mechanism in an NFD is completely different. An NFD has two operations that a management application can use to control subscription to notifications, "start" and "stop". An NFD forwards notifications via responses to a solicited "start" operation without signaling the end of the "start" operation. Hence, a "start" operation will always be pending completion. The manager and agent track this pending status of operations between a manager and an NFD. Both the manager and agent maintain a pending completion list for each link between a manager and agent.

Abstract: Information on GDMO managed objects, including class hierarchy and the name binding templates, is compiled into a naming table. This naming table is built from an inheritance table and the name binding template information. The inheritance table indicates the inheritance hierarchy of the managed object classes. The compiler builds the inheritance table as a square matrix with a row and column for each class, and the classes arranged in an ordered list from highest to lowest in hierarchy. The compiler enters a one at each position in the inheritance table to indicate that the managed object class in the row inherits from the managed class in the column.With the inheritance table as a ready reference, the compiler builds the naming table from the name binding templates available as listed in the GDMO source files. The naming table is a square matrix identical to the inheritance table except the entries in the naming table are not ones and zeros.

Abstract: An automatic palletizer system loads a random set of different size and weight boxes onto a pallet without a prior knowledge of the boxes to be loaded. As the boxes pass along a conveyor belt on the way to the pallet, a weighing, dimensioning, and scanning station determines the weight, dimensions and contents of each box. A processor uses this information to continuously remap the optimal pallet configuration for the loading of the remaining boxes as the pallet is loaded. A queuing station, under direction of the processor, reshuffles the sequence of a limited number of boxes to improve the final pallet configuration. The pallet is loaded by a robot arm under direction of the processor.

Abstract: A digital phase lock loop channel is provided for threshold detection of a pulse width modulated binary data stream that has negative and positive transitions defining one binary state of the data stream. A threshold-establishing and transition-detecting network receives this data stream and provides a first output of one polarity corresponding to the detection of a positive transition, a second output of an opposite polarity corresponding to the detection of a negative transition, and a time-of-arrival output corresponding to a positive and a negative transition. A first and a second digital PLL is provided, each PLL having a transition input, a time-of-arrival input, a phase-error input, a phase error output a data-valid output, and a data output. Each PLL has an internal digital phase detector network connected to receive its transition input and its time-of-arrival input, and each PLL is operable to generate the phase error output therefrom.

Abstract: A method and an apparatus for optimizing movement of a disk drive's head actuator arm away from a magnetic latch that holds the arm in a parked position at the Inner Diameter (ID) of a disk. Current energizing of the arm's actuator motor moves the arm away from the magnetic latch and is controlled to compensate for any change in magnetic holding force. When the disk drive is powered up, a current pulse of one polarity is applied to the actuator motor. This initial current pulse normally moves the arm away from the magnetic latch and is followed by a current pulse of the opposite polarity to decelerate movement of the arm. If this initial sequence fails to move the arm away from the magnetic latch, the magnitude of the two current pulses is increased, and the opposite polarity pulse is followed by a small magnitude current of the one polarity. The read signal from the head is monitored to indicate that the arm has moved into the disk's central databand area, and then into the disk's Outer Diameter (OD) area.

Abstract: A coded logical interrupt signal is sent between system or subsystem units in a data processing system. The logical interrupt is sent by a sending unit, that requests the interrupt, and is sent to a receiving unit that the sending unit wishes to interrupt. These coded logical interrupts are accumulated in the receiving unit. When the receiving unit is actually physically interrupted by control of the processor in the unit, all logical interrupts that have been accumulated are processed. The logical interrupt may be coded to indicate sending unit, that is the source of the interrupt, and the action being requested by the sending unit. If the interrupt includes only source information, the action information is sent separately by the sending unit to memory in the receiving unit. If the interrupt includes both source identification and action information, the receiving unit can interpret source and action directly from the interrupt.

Abstract: This invention relates to a hearing enhancement system having an ear device for each of the wearer's ears, each ear device has a sound transducer, or microphone, and a sound reproducer, or speaker, and associated electronics for the microphone and speaker. Further, the electronic enhancement of the audio signals is performed at a remote digital signal processor (DSP) likely located in a body pack worn somewhere on the body by the user. There is a down-link from each ear device to the (DSP) and an up-link from the DSP to each ear device. The DSP digitally interactively processes the audio signals for each ear based on both of the audio signals received from each ear device. In other words, the enhancement of the audio signal for the left ear is based on the both the right and left audio signals received by the DSP.In addition digital filters implemented at the DSP have a linear phase response so that time relationships at different frequencies are preserved.

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: A method for approximating mathematical functions using polynomial expansions is implemented in a numeric processing system. A partial remainder operation is set forth for high accuracy reduction of polynomials whose arguments are greater than pi/4. The method may be practiced in a processor having a bus of approximately half the width of the precision of the desired result. Temporary registers are utilized for the storage of intermediate results. Full bus width accuracy is obtained through successive half bus width operations.

Abstract: A tie plate with posts is designed for easy insertion of the foot of the rail cooperates with pins through the posts to rigidly affix the rail to the tie plate and to railroad ties or roadbed. The posts may be made of flexible material in which case the rails are snapped into the tie plate. Alternatively the posts may be fabricated from hard plastics, ceramics, or metals, in which case the rails slide into the tie plates. The posts restrain the rail from lifting out of the tie plate or shifting laterally in the tie plate. Pins with fluted, or otherwise textured, surfaces are driven through guiding holes in the posts of the tie plate past the edge of the foot of the rail. The fluted edges of the pin serve to grip the rail. The pins are made of rigid or hard materials so that the pin will provide rigidity to the posts and also slightly deform the edge of the foot of the rail and thereby grip or engage the foot.

Abstract: The user written application program (UAP) operates interactively with an application program interface (API) to produce multiple formatted documents from multiple data records without user intervention. The UAP calls the API to send set-up parameters to the API, and the API is set-up for formatting based on these parameters received from the UAP. The UAP sends page parameters to the API to establish the page environment at the API based on the page parameters. Then the UAP and the API interactively format the data records as paragraphs, tables or other page elements into a page. The interactive format process checks for errors in the format process at the API. The UAP and the API continue to format data unless a detected error is too severe. The format process is a state driven process. A hierarchy of states in the format process is defined, and the calls to the API set a current active state.