Abstract: A circuit arrangement for correcting magneto-resistive head asymmetry includes a shift circuit which receives a read signal from a magneto-resistive head, and a polarity signal indicative of the polarity of any asymmetry of the read signal. Depending on the polarity of the asymmetry, the shift circuit either adds or subtracts a shift voltage to the read signal to produce a shifted read signal. The shift circuit outputs the read signal, the shifted read signal, and the shift voltage. First, second and third gain circuits are provided, which receive the read signal, the shifted read signal, and the shift voltage, respectively, and which each receive a respective control signal. The first, second and third gain circuits provide respective outputs amplified proportionally based on the respective control signals. Control circuitry provides the polarity signal to the shift circuit and the respective control signals to the first, second and third gain circuits, based on an amount of correction required.

Abstract: In storing data on a storage device, for example, a disk drive, it is determined what type of data is to be stored, distinguishing between normal data and slow data, such as audio data or text messages. Slow data is data which can be used effectively when retrieved at a relatively low storage medium speed. Slow data is further assigned to be stored at a predetermined location on the storage medium selected to avoid reliability problems due to the slower medium speed. Storing and retrieving such data at a slower medium speed from the assigned location increases drive efficiency by conserving power without compromising storage device reliability.

Abstract: The internal temperature of a small, temperature-sensitive device, such as a microdrive, can be controlled using a thermoelectric unit to permit the temperature-sensitive device to be used in a wider range of installations. In particular, a thermoelectric unit is provided at the housing of the temperature-sensitive device. A Peltier thermoelectric module is advantageously used to thereby provide an environmental shell that operates in either a heating or a cooling mode.

Abstract: Fail-safe write caching uses specially arranged portions of a disk surface to store write cache data during drive idle time. In case of a system or drive failure before the data is written to its ultimate disk destination, the data can be read from the specially arranged portions to effect recovery without data loss.

Abstract: A carrying bag for receiving a portable personal computer, such as a laptop computer, is configurable to be carried in a briefcase mode, a shoulder bag mode, and a backpack mode. The bag can be configured to form stable frame or platform, thereby placing a personal computer received therein into an ergonomically comfortable position for working with while sitting, standing or even walking. Accessories and appliances can be accommodated within the bag and be readily accessible when the bag is set up as a stable frame or platform.

Abstract: An adapter node is provided for use in adapting internal system enclosure services to a system power control network to thereby provide remote power control, diagnostics, and logical-to-physical correlation information, through the system power control network. The adapter node is for use in one computer of a plurality of different types of computers, having a respective internal system enclosure services low-level communication path. The power control network has a plurality of nodes, one of the nodes being a control node. The adapter node includes a substrate having electrical contacts adapted to plug to a system bus in the one computer. The substrate further has at least one system enclosure services interface connection to connect to the internal system enclosure services low-level communication path in the one computer. The adapter node further has a system power control network interface connection for connecting to the system power control network.

Abstract: Detection of a failure in a multi-system application, includes detecting a first message between a first system and a second system and creating a connection object representing a connection between the first system and the second system. Thereafter, connection status is monitored with the connection object to detect a connection or system failure. The same connection object is used for all subsequent messages between the first system and the second system. The multi-system application uses service objects on the first and the second system, and when a connection or system failure is detected, failure handling is initiated, including notifying all service objects of the failure.

Abstract: In an electrical system having a chassis with at least one chassis slot for receiving a chassis electrical device, and at least one connector board with at least one board slot thereon for receiving a connector board electrical device therein, respective memory is provided for storing vital product parametric data associated with the at least one chassis slot, the at least one connector board slot, and the respective electrical devices. The stored vital product parametric data can be accessed by the electrical system to check compatibility.

Abstract: A power supply includes a rectifier which receives alternating current as an input, and which provides an output of direct current pulses at a positive polarity output line thereof with respect to a negative polarity output line thereof. A back-up circuit is coupled between the positive and negative polarity output lines of the rectifier. The back-up circuit includes the series connection of a switching device, a current blocking device, at least one electrical energy source device, and a current measuring device. A circuit protection device may also be provided in the series connection. The back-up circuit can be tested while the rectifier is providing the direct current output pulses by closing the switching device and detecting at least one pulse of a test current flowing through the back-up circuit and/or a terminal voltage of the at least one electrical energy source device during the testing.

Abstract: A liquid enriched with a high concentration of gas, in particular, water enriched with oxygen, is produced by mixing the gas and liquid in an overpressurized system using a series of pressure reduction containers which sequentially reduce the pressure on the gas-enriched liquid in a slow incremental fashion, thereby allowing a high concentration of the gas to be maintained within the liquid phase.

Abstract: In an electrical interface providing a predefined number of connections at least some of which have predefined functions and at least some of which have reserved, undefined or non-critical functions, selective use of at least one of the connections having a reserved, undefined or non-critical function is accomplished. At least one switch is provided which is controllable and coupled to switch at least one connection having a reserved, undefined or non-critical function to a desired customized function. In this way, the electrical interface can be selectively switched to provide additional functionality using reserved, undefined or non-critical connections of the interface.

Abstract: A system start-up routine is implemented to determine system device power requirements and system power capabilities, determine a maximal number of devices which can be started at one time, and start the maximal number of devices. The devices are, for example, direct access storage devices, i.e., disk drives.

Abstract: An autodocking assembly for use with a circuit board includes a card holder adapted to accommodate and secure one of a plurality of electronic cards therein, and a pivot arm attached to the card holder which is adapted to pivot such that an edge connector of the one electronic card in the card holder docks with a corresponding slot connector on the circuit board.

Abstract: A driver for a signal line provides a desired pull-up voltage, different from a natural supply voltage, and desired terminating impedance. The driver forms a controllable split terminator voltage divider.

Abstract: In an electrical system, concurrent maintenance of a system component coupled to the system by an adapter on a first communications path is accomplished through the provision of a second communications path to a system power controller, so that concurrent maintenance is not dependent on communications over the first communications path. In particular, concurrent maintenance of a direct access storage device (DASD) coupled to a computer system through a small computer system interconnect (SCSI) bus, an input-output adapter (IOA), a peripheral component interconnect (PCI) bus and a PCI bridge circuit (PCIB), is enabled by providing a IIC serial, point-to-point signal path between the bridge circuit and a system power control network (SPCN) to coordinate quiescing of the SCSI buses and powering down of the DASD.

Abstract: A power system includes a battery back-up unit (BBU) having back-up battery circuitry which provides battery back-up support for a plurality of power supplies each having a respective power factor correction circuit front-end with a boost stage. The voltages output from the boost stages of the power supplies are monitored and compared with respective reference threshold voltages to derive a signal which is used to bring battery back-up power on-line when a monitored voltage falls below a threshold voltage, which may be indicative of a loss of AC mains input voltage. AC mains input voltage is also monitored to detect a restoration and disconnect the battery back-up power. In the event that battery back-up is brought on-line due to a faulty power supply rather than a loss of AC mains input voltage, the faulty power supply can be masked and reported for repair.

Abstract: Routing asynchronous state changes in a multi-processing system having an end user system, a central application server system and an endpoint system, includes detecting a state change with a service object on the endpoint system, sending a notification to an associated service proxy object on the central application server system notifying the associated service proxy object of the state change, sending a notification to an associated distributed service object which is an owner of the service proxy notifying the associated distributed service object of the state change, sending a notification to an associated distributed service proxy object on the end user system notifying the associated distributed service proxy object of the state change, and posting an event to an associated owner window of the distributed service proxy object using a window identifier including sending a notification to the associated owner window notifying the associated owner window of the state change.

Abstract: The melting point of the solder forming a controlled collapse chip connection is tailored by forming a thin metal cap of a metal such as palladium or silver on a solder bump. When the solder bump is melted during reflow, the metal cap dissolves into the solder. Because the resulting alloy has a higher melting point than the solder, subsequent reflow processing does not melt the chip join structure.

Abstract: A communications network includes a primary node and one or more secondary nodes, each node having first and second ports. The primary node periodically polls the network in opposite directions to determine if the network is operating as a loop, or as open chains. The secondary nodes memorize at which port a message is received, and use this information to determine the port at which to output the message, or to output a response message, depending on the type of message received. First and second timers are used depending on whether a successfully received message is a command or a response. If a subsequently received message is garbled, it is stopped from further propagation and an error message sent. The timers are checked and a determination can be made whether the garbled message was a command or a response.

Abstract: A liquid enriched with a high concentration of free gas, in particular, water enriched with free oxygen, is produced by mixing the gas and liquid in an overpressurized system to form a mixture and then abruptly reducing the pressure of the mixture. Alternatively, the pressure reduction may be accomplished using a series of pressure reduction containers which sequentially reduce the pressure on the gas-enriched liquid in a slow incremental fashion, thereby allowing a high concentration of free gas to be maintained within the liquid phase.