Abstract: A self servo writing file and method for writing servo patterns in a direct access storage device are provided. First servo information is written on a data storage media at a first crash stop. The transducer heads are moved offset from the written servo information while reading the last written servo information until the detected servo signal equals a predetermined value. Then servo information is written on the data storage media responsive to the detected servo signal equal to the predetermined value. The moving and writing steps are sequentially repeated until a second crash stop is reached. A quad-burst servo amplitude pattern or phase pattern can be used for the servo information. The servo writing method is adapted easily for many different servo options. When the file uses a hybrid servo or sector servo, the other surfaces can be written by duplicating the servo bursts with a high bandwidth servo system of the file.

Abstract: A processor book includes a processor card having front and rear surfaces, and at least one high heat component attached to the front surface. Two separate flows of cooling gas are conveyed to the processor card from two separate directions. A cooling duct is provided adjacent to the front surface of the processor card, and conveys one of the flows of cooling gas. The cooling duct has an outlet in a region of the high heat component.

Abstract: Disclosed is a disk drive having at least one disk for storing data. The disk drive includes at least one transducer for reading or writing data to or from the disk. The transducer is attached to an actuator which positions the transducer with respect to the disk. The actuator includes a controllable motor which is used to move the actuator and the transducer attached thereto. The disk drive also includes a ramp for off loading the transducer or for parking the transducer off of the surface of the disk. Also disclosed is apparatus and methods for measuring and controlling the movement of the actuator and attached transducer while the transducer is coming from a position off of the ramp and onto the surface of the disk.

Abstract: A plurality of information circuits are provided for a computer system. Each information circuit is associated with an element of the computer system and each stores data about the associated element of the computer system. The stored data is accessed by a control device of the computer system in order to configure predetermined operating parameters of the computer system elements.

Abstract: A method and apparatus are provided for detecting handling damage in a direct access storage device (DASD). The DASD has at least one disk mounted for rotation and a transducer mounted for movement across tracks recorded on the at least one disk. Each of the tracks being divided into a plurality of sectors. A handling damage analysis test is performed within a predetermined damage zone on the at least one disk. Test results from the handling damage analysis test are compared with at least one threshold value. An error code is outputted responsive to compared test results being greater than the at least one threshold value. A microcode routine is stored in a random access memory (RAM) in the DASD. The microcode routine is performed for detecting handling damage in the direct access storage device (DASD) upon installation. An error code is outputted to a host interface responsive to compared test results greater than a threshold value.

Abstract: Described is a system and method of communicating between first and second nodes connected by a serial link wherein the data is transmitted between the nodes in the form of packets made up of multiple bit frames. Each packet that is correctly received by the second node is acknowledged by means of a pair of multibit frames. These frames may be interleaved among the frames making up any outgoing data packet that is being transmitted by the second node. The technique employed provides unambiguous acknowledgment of each data packet and if a data packet is received incorrectly, the packet is available in a buffer in the first node for resending.

Abstract: A cleavable epoxy resin composition suitable for encapsulating electronic chips and a method for making the composition comprises the cured reaction product of a diepoxide; a cyclic dicarboxylic anhydride curing agent mixture; a 1,3-diaza compound having two nitrogen atoms present with one nitrogen atom doubly bonded to the central carbon and singly bonded to one other carbon, and the other nitrogen atom singly bonded to the central carbon and singly bonded to another carbon and singly bonded to a hydrogen. The 1,3-diaza compound serves either as the sole catalyst or in combination with a tertiary amine catalyst different from the diaza compound. The composition may include an optional hydroxy functional compound capable of reacting with the cyclic anhydrides to form a half ester thereby initiating the reaction between the diepoxide and the cyclic dicarboxylic anhydride curing agent. The resin can be used for the encapsulation of electronic parts, but can be removed by a solvent.

Abstract: An apparatus for preventing leakage of electromagnetic radiation from a modular electronic planar substrate surrounded by an enclosure that includes a bottom portion, a top portion, a first side portion having apertures adapted for receiving electronic cables, and a second side portion having electrical connections therein. The apparatus includes a bracket having a first end and a second end, the bracket connected to the first side portion, wherein the bracket includes an interior portion and an outer portion which contiguously form a first bracket wall, a second bracket wall and a third bracket wall, such that the second bracket wall is positioned approximately perpendicular to the first bracket wall and the third bracket wall.

Abstract: A computer system automatically senses characteristics of diverse peripheral devices connected to a common communications port, and automatically maximizes the communications speed with the devices. Coupled in daisy chain fashion to the communications port, all peripheral devices receive every signal issued from the controller port, each device responding only to signals addressed to that device or signals addressed to a universal address. The controller first receives an identifier from peripheral devices attached to the controller port. The controller then interprets the received identifiers to determine a maximum communications speed for each device. Next, the controller and the attached peripheral devices are configured to communicate at the maximum communications speed of the slowest device. This guarantees that all messages sent by the controller are compatible with all peripheral devices.

Abstract: A method and apparatus for controlling a multiple-stage actuator for a disk drive which does not require an additional sensor for measuring the relative position between adjacent actuator stages. In a two-stage actuator system, a position-type secondary actuator (SA) rides piggyback on a primary actuator (PA). The repeatable runout is measured and used as a feedforward signal to the PA. If the PA is a rotary actuator, the feedforward signal is preferably arc corrected for the arc that the head transverses from the inner radius to the outer radius of the disk. Added to the feedforward signal is the moving average of the drive signal applied to the SA. Because the SA is of the position-type having a neutral position, this moving average is proportional to the time cumulative drift present in the two-stage actuator system, and forces the PA in a direction that minimizes deviation of the SA from its neutral position.

Abstract: A multiple supply voltage peripheral component interconnect (PCI) connector is disclosed which replaces connectors that are keyed for a specific signaling voltage. A single connector receives all current types of PCI keyed card edge connectors and supplies the correct signaling voltage thereto. The type of PCI card is identified and the appropriate signaling voltage is switched to the signaling power input (Vio) using industry standard conditions at selected pin locations rather than using unique keying of cards and connectors to assure a match between the signaling voltage required by the card and the signaling voltage supplied at the connector. As shown, detection and control circuitry senses the presence of grounded or open conditions at selected pin locations indicative of the type card present in the connector and switches the signaling power supply to the correct voltage source.

Abstract: A printed circuit connector terminal pad coating technique is disclosed which functions as a single universal pad surface which supports multiple electrical connection practices including wirebonding, soldering, and wear resistant, pad on pad mechanical connection. The tri-plate surface treatment includes an initial diffusion resistant coating of nickel; an intermediate layer of hard, wear resistant noble or semi-noble metal that provides pad on pad connector reliability and affords a metallurgically stable solder joints and wirebond interfaces; and a final coating of soft gold. The intermediate layer may be pure palladium having a nominal thickness of 35 microinches or a layer of gold, hardened by cobalt, nickel, iron or a combination of these dopants to effect a hardness of 200 to 250 (Knoop scale). The use of a common surface treatment for the multiple attachment processes is implemented with a single masking step, rather than a sequence of selective masking, plating and stripping operations.

Abstract: An actuator structure includes a flexure suspension with a flag appendage having a cantilevered portion extending parallel to the arm-suspension to form a gap therebetween. The flex cable that connects to the device electronics has an elongated portion secured to the side of the arm-suspension assembly presenting termination pads, which extend to the cable edge, along the elongated portion side and in alignment with the gap between arm-suspension and flag. The leads extending from the transducer are fanned out and extend across the gap. The leads are bonded to the arm-suspension and to the lead cantilevered portion immediately adjoining the gap. To terminate the leads, the flag is folded down 90 degrees, bringing the leads into contact with the termination pads where they are ultrasonically bonded. The flag is then bent toward its original position causing the fine lead wires to separate between the flag cantilever portion bond and the ultrasonically bonded termination.

Abstract: A technique for preventing damage to ball bearings in small form factor devices where the drive motor has at least one piezoelectric crash stop ring disposed about the shaft and inside the rotor of the motor. The crash stop ring must be dimensioned to permit only a small amount of movement of the rotor relative to the shaft. The permitted movement is less than the minimum movement which would cause damage to the elements of the ball bearing.

Abstract: A system for removing protective coatings from a circuit board assembly. The system includes a tool for removing protective coatings from a circuit board assembly. The tool has a flow head, which includes a support, having an opening which is adapted to contact the circuit board assembly and flow solvent to the surface of the circuit board. The flow head may also include a solvent nozzle positioned within the support. The solvent nozzle has an opening adapted to apply solvent to the circuit board assembly. The flow head also includes a solvent recovery volume positioned beneath the support and adjacent to the nozzle. The system also includes a second solvent reservoir, a mechanism for applying heat to the reservoir, and a mechanism for circulating solvent from the reservoir to the flow head and back to the reservoir.

Abstract: An enclosure and method for enclosing electronic devices. The enclosure includes channel-shaped members that each have a convex side and a concave side. The enclosure further includes a substantially planar outer surface and an attachment device for attaching the substantially planar outer shell to the concave side of the channel-shaped member such that a rigid, enclosed, substantially tubular structural member is formed, thereby forming a rigid chassis. Additionally, the attachment device includes a trench-shaped member, attached to said substantially planar outer shell, and located between the channel-shaped member and the substantially planar outer shell. The trench-shaped member also includes a fixed device for temporarily fixing the trench-shaped member to the concave side of the channel-shaped member. The enclosure includes four channel-shaped members, such that each channel-shaped member includes a corner post positioned within the enclosure apparatus to form a substantially rectangular structure.

Abstract: A direct access storage device includes at least one disk mounted for rotation about an axis and having opposed disk surfaces for storing data. A magneto-resistive (MR) transducer head is mounted for movement across each respective disk surface for writing to and for reading data signals from the disk surface. Each MR transducer head includes a write element and a read element. A preamplifier, associated with the MR transducer head, amplifies read and write signals of the read element and the write element. A flex cable couples the read and write signals between the preamplifier and the MR transducer heads. The flex cable includes a common read return signal line for each sequential pair of the MR transducer heads.

Abstract: Raised irregularities in a magnetic data storage disk are removed by contacting an MR head with the relatively softer irregularity to abrasively erode the irregularity. The MR head may be brought into contact with the irregularity, for example, by selectively increasing read bias current of the head to expand the head toward the disk. Advantageously, removal of such imperfections helps eliminate thermal asperities created when the head inadvertently contacts raised irregularities during reading of data.

Abstract: An electrical connector system uses two electrical connector housings and two mating electrical connectors. The electrical connector housings are disposed on a support plate in an end to end relation and spaced apart by a distance smaller than twice the distance from the electrical connector housing to the fastener holding the connector to the connector housing. The fasteners are carried by and engaged with a retainer bar that further engages the connectors to pull the connectors into the connector housings and retain them in connection relationship, ensuring reliability of the connection.

Abstract: An enhanced peripheral component interconnect (PCI) architecture for a data-processing system is described. In accordance with the method and system of the present invention, a peripheral component interconnect (PCI) architecture for a data-processing system comprises a PCI host bus, a number of PCI local buses, and a PCI hot-plug bridge. Each of the local PCI buses has an adapter card slot. The PCI hot-plug bridge, connected between the PCI host bus and the PCI local buses, is utilized for controlling power to each of the PCI local buses, such that a PCI adapter card may be removed from or added to any one of the adapter card slots during power up while there is processing ongoing within adapter card(s) situated in other adapter card slot(s).