Abstract: A defect management system for use in a data storage system. The defect management system generates a track defect list comprising a sector defect record for each of a set of defective sectors in a track of a media surface. A sector defect record includes defect management information for each of the defective sectors. The defect management information may be generated according to one of several defect management schemes. The apparatus of the present invention stores the track defect list in a buffer or sector headers. The apparatus of the present invention maps a physical sector number to a logical sector number using the track defect list. If the track defect list is stored in sector headers, the present invention may use a ping-pong FIFO for processing the track defect list.

Abstract: A single-chip, network interface controller (NIC) integrated circuit (IC) with a host interface and arbiter common to two 10BASE-T ETHERNET local area network (LAN) segments with respective unshielded twisted pair interfaces, encoder-decoders, medium access controllers, first-in first-out register memory arrays, and buffer management. Source-address and destination-address content addressable memories are connected to respective MAC receivers in the medium access controllers to both learn the addresses of network clients on the two segments and then to transparently bridge packets between the LAN segments. The NIC effectively increases the bandwidth of a server connection to the thus unified network.

Abstract: A circuit for supplying power to a fluorescent lamp comprising a buck regulator with a high side drive. A dc battery is coupled to a drain of a first transistor. A source of the first transistor is coupled to an inverter for powering the lamp. A first control signal is coupled to a primary winding of a transformer. A first terminal of a secondary winding of the transformer is coupled to the anode of a diode. The cathode of the diode is coupled to the gate of the first transistor. A second terminal of the secondary winding of the transformer is coupled to the source of first transistor. The first control signal is activated to bias the first transistor through the transformer by charging the gate to a voltage higher than the control voltage due to the transformer turns ratio. A diode is coupled to capture a charge on the gate. A second transistor is coupled to the gate of the first transistor to drain the captured charge to ground, turning off the first transistor when a second control signal is activated.

Abstract: An adaptive equalizer is configured to reconstruct electronic signals which are transmitted over signal cables, such as twisted pair cables. The equalizer satisfactorily reconstructs the signals over a broad range of cable lengths. The degradation characteristics of a signal cable varies with cable length. Using the degradation characteristics for a cable over a desired range of lengths, the adaptive equalizer includes multiple parallel paths each of which are configured to reconstruct the input voltage signal optimized for a particular cable length. The degraded input signal is split according to a predetermined relationship into multiple partial signals, each signal for transmission through one each of the paths. Though each path is optimized to reconstruct the signal for a particular length of cable, the adaptive control adds a function of the actual cable length for more accurately reconstructing the signal. Each path forms a partial reconstructed signal.

Abstract: A DC-to-DC converter having hysteretic inductor current limiting and that does not have a resistor continuously carrying the inductor current. A voltage supply is coupled to a drain of a first transistor. A source of the first transistor is coupled to a first terminal of the inductor and to a drain of a second transistor. A source of the second transistor is coupled to ground through a resistor. A second terminal of the inductor is coupled to a first terminal of a capacitor. When the first transistor is on, the second transistor is off, causing current in the inductor to increase. The current flowing through the inductor charges the capacitor, and stores energy in the inductor as an increasing magnetic field. When the first transistor is off, the second transistor is on, and the stored energy is converted back into current, continuing to charge the capacitor. Voltage across the capacitor is regulated for powering a load by controlling the first and second transistors in a feedback loop.

Abstract: An apparatus for providing register compatibility between integrated circuits having different register and interrupt configurations is designed to operate with software. Software may attempt non-native register accesses; the integrated circuit of the present invention will emulate a non-native register set. In the preferred embodiment only one physical register set is included on the integrated circuit and a compatibility engine is used when a non-native register access is attempted. The compatibility engine is coupled between a bus interface unit and the physical register set and allows a user or system designer to address a register set of another integrated circuit having a different configuration than the physical register set. The compatibility engine converts the address and maps the data bits of the emulated register into registers within the physical register set. Alternatively, two sets of registers can be physically included on the integrated circuit.

Abstract: A circuit for driving a brushless dc motor includes an active deceleration circuit for rapidly slowing the motor. A phase locked loop senses a position of the rotor for commutating from a drive state to a next drive state in a sequence of drive states at an appropriate time for maintaining torque on the rotor in the direction of rotation. Thus, the rotor "chases" the energized windings. A speed control loop controls current in the windings and, thus, motor speed. When the speed of the motor exceeds a desired speed by more than a threshold amount, rather than commutating to a next drive state in the sequence, the circuit skips a commutation. By skipping one commutation, the current drive state is maintained while the rotor continues to turn, due to its own inertia, such that the rotor "passes up" the current drive state. This results in a torque on the rotor in a direction opposite rotation.

Abstract: A socket for connecting the contact pads (34) of an electrical circuit board (5) to the contact points (32) of an integrated circuit package (14). The socket has a socket body (7) including a first plurality of holes (27) and a floating guide plate (12) including a second plurality of holes (24). A plurality of contact springs (11) are supported between the socket body (7) and the floating guide plate (12). Each contact spring (11) has a first end (21) and a second end (22) with a resilient part (20) between the first end and the second end.

Abstract: A highly efficient in-line fluid heater is suitable for heating ultra-pure fluids. Preferably, the heater can be used for heating various fluids, including water, as part of a "wet bench" system used in a wafer processing fabrication facility for the semi-conductor industry. Many other uses for this in-line heater can be envisioned; e.g., water industry, gas processing, and any other use requiring an ultra-clean, highly efficient, non-contact method of raising the temperature of various liquids and gases. The preferred in-line heater utilizes one or more elongated lamps that generate IR radiation as the heating elements. A vessel is provided through which the fluid to be heated is passed. Typically, the vessel is a tube. The tube is preferably a straight single diameter tube, but can be formed in any convenient shape. For ultra-pure fluids, the vessel is formed of an inert or non-reactive material such as quartz. Preferably, the vessel is transparent to the IR radiation generated by the lamps.

Abstract: A portable emission microscope for analyzing failures in an integrated circuit chip while the chip is contained within a wafer sorter. A base for the microscope is placed over an opening in the wafer sorter. A translational apparatus is attached to the base for lowering a charge coupled device camera into an opening in the wafer sorter. A compact housing containing microscope optics is coupled to the camera. Also, a flexible rubber boot is coupled to the microscope optics for shielding extraneous light from entering the camera. A vibration reducing apparatus is coupled to the microscope optics for preventing movement of the camera relative to the chip. The vibration reducing apparatus fits within the rubber boot and is a rigid, hollow cylinder having an adjustable length. The microscope optics view the chip through the cylinder.

Abstract: A technique for sensing current that employs an internal current sensing resistor. Two current sources of small and equal magnitude pull currents from two identical PNP transistors. Two PMOS transistors supply current to the PNP transistors. The PMOS transistors are scaled so the transistor on the output side of the circuit has an aspect ratio much greater than that of the transistor on the sensing side of the circuit. The result is that the currents through the PMOS transistors are proportional to each other and the current on the sensing side is much smaller than the current on the output side. The output current is the difference between the current through the PMOS transistor with the greater aspect ratio and the current through one of the small current sources. The sensing current, which passes through the internal sensing resistor, is the difference between the current flowing through the PMOS transistor with the lesser aspect ratio and the current flowing through the other small current source.

Abstract: A circuit for sensing a current in a fluorescent lamp. A control system comprises a buck regulator circuit for supplying a buck current, an inverter circuit for receiving the buck current and for generating a lamp voltage, a circuit for sensing a current in a fluorescent lamp, and a controller for controlling the buck regulator and the inverter. The inverter comprises a Royer-type inverter, a resonant tank, and a transformer. A current flows through a primary winding of the transformer to generate a voltage in a secondary winding of the transformer. The fluorescent lamp is coupled to the secondary winding of the transformer so that the fluorescent lamp is isolated from the remainder of the control system by the transformer. The circuit for sensing the current in the lamp senses a current in the Royer-type inverter which is representative of the current in the lamp. The circuit for sensing the current in the lamp is coupled to the controller for controlling the buck regulator and the inverter.

Abstract: A personal computer chassis having increased reliability, versatility and decreased manufacturing costs. In a first embodiment, a disk drive is installed in the chassis in a first orientation for resting the computer on a desk top or in a second orientation, rotated 90 degrees from the first orientation, for resting the computer on a floor. The chassis is configured to allow interchangeable trim plates. When the trim plate is used as a base plate it has a larger periphery than when used as a side trim plate. In a second embodiment, a disk drive may be installed in the chassis without screws. Spring urged clips allow the disk drive to be easily inserted into the computer chassis, yet provide secure attachment. In a third embodiment, electrical contact is ensured for input/output port covers attached to the rear of the computer chassis. Each cover is made to bend slightly over protrusions on the computer chassis, forcing the cover into firm contact with the protrusions.

Abstract: A method for metallizing semiconductor materials includes two processing steps. In the first step, a layer of an alloy of conductive metal, such as aluminum, and an Alloy Material such as hafnium, tantalum, magnesium, germanium, silicon, titanium, titanium nitride, tungsten and/or a composite of tungsten, is deposited on the surface in a single step from a single source. In the second step, a layer of the conductive metal is deposited over the alloy layer. Thus, using this method, metallization can be conveniently performed using two chambers.

Abstract: An integrated circuit controller for power factor correction circuit that provides unity power factor by sensing only a current in the power factor correction circuit and a dc supply voltage. The power factor correction circuit is coupled to a circuit for generating the dc supply voltage. Thus, the dc supply voltage is representative of the regulated output voltage of the power factor correction circuit. The dc supply voltage is sensed and integrated over each clock cycle and compared to an inverted and amplified version of the sensed current for controlling operation of the power factor correction circuit. By sensing the dc supply voltage, rather than the output voltage of the power factor correction circuit, the integrated circuit requires fewer pins. In a preferred embodiment, the integrated circuit also includes a pulse width modulation controller circuit.

Abstract: A power supply for an instrument that measures waveforms on AC (alternating current) power systems. Under ordinary circumstances, the power supply draws its power from the signal that the instrument measures. The power supply includes energy storage means. When the instrument must make a precise measurement that could be affected by the power drawn by its power supply, the instrument temporarily disconnects its power supply from the measured signal and draws power from its energy storage means, effectively coasting on the stored energy. At the conclusion of the precise measurement, the instrument reconnects its power supply to the signal being measured.

Abstract: The present invention provides novel methods, forms and devices for simultaneously capturing handwriting on one or more forms and on an electronic device including a membrane digitizer, wherein the forms are integrated with the digitizer.. Proper alignment between the digitizer surface and a business form placed on the digitizer surface is electronically checked. The form is removably affixed to the digitizer by means of an adhesive.