Abstract: A multiport repeater for a data network operating on a CSMA or CSMA/CD protocol, for example an Ethernet local area network, has signals transmitted from port to port via a crosspoint switch or other appropriate switching means. The destination address of each incoming data frame is read and compared with a stored table to determine which port or ports the frame needs to be transmitted to, and the switching means is then operated to cease transmitting the frame unnecessarily to other ports. The remaining ports are thus returned to an idle state, and a second frame overlapping with the first can be received and retransmitted provided it does not require any of the ports that are in use in transmitting the first frame.

Abstract: A small diameter multimode optical fiber with a low numerical aperture (i.e., 0.1) is used as a microlens to collimate the output emissions of a laser diode before butt coupling the output of the laser diode to an optical fiber. The optical fiber used as the microlens is chosen such that its diameter roughly equals the diameter of the fiber to be coupled to the laser diode. One end of the fiber is mounted in a fixed position and the other end of the fiber is slip fit into the end of a hollow receiving member mounted in a fixed position and running parallel to the axis of the fiber. The collimation is performed in the high NA direction of the output of the laser diode. The output of a bundle of butt coupled optical fibers may be used to pump a laser system.

Abstract: Early initiation of transmission of data in a network interface that includes a dedicated transmit buffer is provided in a system which includes logic for transferring frames of data composed by the host computer into the transmit buffer. The amount of data of a frame which is downloaded by the host to the transmit buffer is monitored to make a threshold determination of an amount of data of the frame resident in the transmit data buffer. The network interface controller includes logic for initiating transmission of the frame when the threshold determination indicates that a sufficient portion of the frame is resident in the transmit buffer, and prior to transfer of all of the data of the frame into the transmit buffer. The monitoring logic includes a threshold store, which is programmable by the host computer for storing a threshold value. Thus, the threshold value may be set by the host system to optimize performance in a given setting.

Abstract: An improved optical fiber for laterally directing a laser beam having a waveguide including a tip for communicating electromagnetic radiation in a propagation direction to the tip of the waveguide, a transmitting surface on the tip of the waveguide, a reflecting surface on the tip of the waveguide for internally reflecting electromagnetic radiation communicated by the waveguide in a direction lateral to the propagation direction toward a particular area on the transmitting surface, and wherein the particular area and the reflecting surface are disposed so that substantially all electromagnetic radiation reflected by the reflecting surface is incident on the particular area at below a critical angle for transmission through the transmitting surface in the lateral direction.

Abstract: A system for interconnecting networks transparently extends the multiprotocol routing functionality of a router across a communication link to a remote LAN, while requiring a device on the remote LAN which operates independent of the higher layer protocol suites. A boundary router, having a local routing interface coupled to the first network, and a remote routing interface coupled to the communication link, provides the higher level protocol suite services for routing frames of data to terminals in the first and second networks. A routing adapter extends the remote routing interface of the boundary router transparently across the communication link to the second network.

Abstract: A voltage detection circuit for preventing the erasing and programming of a nonvolatile memory device during power up and power down sequences. A power source is coupled to the high voltage input and the low voltage input to provide a reference voltage in response to the greater of the high voltage input or the low voltage input. A low voltage detector is coupled to the low voltage input and the reference voltage and has circuitry to provide a first not-ready signal when the voltage on the low voltage input falls below a predetermined low voltage threshold. A high voltage detector is coupled to the high voltage input, the reference voltage, and the output of the low voltage detector and has circuitry to provide a second not-ready signal when either the first not-ready signal is received or the voltage on the high voltage input falls below a predetermined high voltage threshold. The not-ready signals prevent erasing or programming operations to occur in the nonvolatile memory device.

Abstract: A FLASH EPROM device includes a memory array organized into a plurality of blocks of memory cells. An energizing circuit applies energizing voltages to the blocks of memory cells to read and program addressed cells, and to erase selected blocks or the whole memory array. An erase verify circuit separately verifies erasure of blocks in the plurality of block memory cells. Control logic controls the energizing circuit to re-erase blocks which fail erase verify. The control logic includes a plurality of block erase flags which correspond to respective blocks of memory cells in the array. The erase verify is responsive to the block erase flags to verify only those blocks having a set block erase flag. If the block passes erase verify, then the block erase flag is reset. Only those blocks having a set block erase flag after the erase verify operation are re-erased. To support this operation, the circuit also includes the capability of erasing only a block of the memory array at a time.

Abstract: A high efficiency, diode pumped laser includes a resonator mirror and an output coupler which define a nearly confocal resonator. Positioned in the resonator is a laser crystal. A diode pump source supplies a pump beam to the laser crystal and produces an output beam. A strong thermal lens transforms a non-confocal resonator to a nearly confocal resonator. The TEMOO mode diameter in the laser crystal may be smaller than the pump beam diameter that is incident on the laser crystal. Output powers greater than about 4 W are achieved, the overall optical efficiency is greater than about 25%, and an optical slope efficiency in a TEMOO mode of greater than 40% is possible.

Abstract: A surgical probe for use in a hollow vessel or other region of the body which comprises a multi-lumen catheter having a transparent, non-compliant balloon coupled to the distal end, such that the balloon has a known shape when inflated. A direct visualization scope is provided in a first lumen of the multi-lumen catheter providing direct visualization into the hollow vessel through the non-compliant balloon. An adapter is coupled to a second lumen of the multi-lumen catheter near the proximal end to supply a transparent fluid through the second lumen to inflate the balloon to the predefined shape. In this aspect, the balloon operates to clear the scope tip by pressing tissue on the walls of the hollow vessel out of the way of the end of the scope. This provides the user of the device a consistent clear view of the tissue at the tip of the scope. A fiber optic is provided in a third lumen of the multi-lumen catheter to deliver light energy to the hollow vessel through the non-compliant balloon.

Abstract: A surgical probe, and procedure using the same, enabling a surgeon to cut body tissue by delivering energy, such as a laser beam, to the body tissue and without removing the instrument to cauterize the body tissue by direct application of electric current. The surgical probe includes an elongated member having a fiber optic positioned on a longitudinal axis of the elongated member and pair of elongated electrodes that span an entire length of the elongated member. The elongated electrodes slide lengthwise in a direction parallel to the longitudinal axis. During cutting procedures, the distal ends of the electrodes are in a retracted position not beyond the distal end of the elongated member, and during cauterization procedures, the distal ends of the electrodes are in an extended position beyond the distal end of the elongated member. In a preferred embodiment, the distal ends of the electrodes are pre-bent so as to converge toward each other as they are extended beyond the distal end of the elongated member.

Abstract: Novel contactless FLASH EPROM cell and array designs, and methods for fabricating the same is based on a unique drain-source-drain configuration, in which a single source diffusion is shared by two columns of transistors. An elongated first drain diffusion region, an elongated source diffusion region, and an elongated second drain diffusion region, are formed in a semi-conductor substrate along essentially parallel lines. Field oxide regions are grown on opposite sides of the first and second drain diffusion regions. Floating gates and control gate wordlines are formed orthogonal to the drain-source-drain structure to establish two columns of storage cells having a shared source region. The shared source region is coupled through a bottom block select transistor to a virtual ground terminal. Each drain diffusion region is coupled through a top block select transistor to global bitline.

Abstract: A circuit is provided for supplying a negative high voltage to an integrated circuit from a high positive voltage source V.sub.PP. The negative voltage is applied to a plurality of FLASH electrically erasable programmable read only memory (EPROM) cells. The circuit includes an oscillator coupled to a voltage converter which provides a periodic signal. The periodic signal is coupled to a charge pump including three P-channel type transistors to produce the negative voltage. The source and drain of the first transistor is coupled to the periodic signal. The second transistor's gate and drain is coupled to a reference ground potential with the source coupled to the first transistor's gate. Finally, the third transistor's drain and gate is coupled to the first transistor's gate and the third transistor's source outputs negative voltage to floating gates of the plurality of FLASH EPROM cells during an erase operation. Further, the negative voltage generated is relatively precise, so no regulation is required.

Abstract: An N-way bridging system for local area networks (LANs) through which a source routed frames are transmitted, is based on hardware filtering in bridge ports responsive to the input LAN and bridge identified in the source routed frame, independent of the output LAN identified in the source routed frame. This filtering forwards the frame to the bridge host processor if a match on the input LAN and bridge number is detected. The host then reads the output LAN parameter from the frame and determines the appropriate routing. This technique preserves the hardware filtering of the IBM Source Routing specification for token ring LANs at least in part, and is assisted by the bridge host processor in determining the output port on the bridge.

Abstract: A data path aligner transfers data from an input having N byte lanes with byte enable bits to an output having N byte lanes. The aligner includes first stage having N-1 selector/registers, and a second stage having N selector/registers. Each of the N-1 selector/registers S1(i) in the first stage has inputs including input lanes L(j) for j going from i+1 to N. Each of the selector/registers S2(i) in the second stage has inputs including input lanes L(k) for k going from i to 0, and for selector/registers S2(i) for i less than or equal to N-2, the inputs include the output of a first stage selector/register S1(i). The outputs of the second stage selector/registers supply data selected from the respective inputs to output segment lanes. All of these selector/registers are controlled by a common select signal derived from a data path offset, and all selector/registers are clocked by a common clock.

Abstract: A high powered OPO system which produces a substantially collimated, low divergence output beam is based on the use of an unstable resonator. An optical parametric gain medium, such as beta-barium borate (.beta.-BBO), lithium tri-borate (LBO), cesium borate (CBO), potasium tri-phosphate (KTP), or other similar materials is mounted within the unstable resonator with suitable tuning mechanisms. Optics are provided for supplying a pump beam through the optical parametric gain medium to induce gain. In a preferred system, the unstable resonator comprises a positive branch, confocal unstable resonator. Further the unstable resonator may be injection seeded for a narrow linewidth output.

Abstract: A LAN or other data network includes at least first and second repeater units for receiving data signals and repeating them to other parts of the data network and a transceiver unit for transmitting and receiving data which is connected to the first repeater unit by a primary data link and to the second repeater unit by a secondary data link. The primary data link comprises a primary transmit line for transmitting data from the transceiver unit to the first repeater unit and a primary receive line for receiving data from the first repeater unit and transmitting it to the transceiver unit; and the secondary data link comprising a secondary transmit line for transmitting data to the second repeater unit and a secondary receive line for receiving data from the second repeater unit and transmitting it to the transceiver unit.

Abstract: A multiport repeater for a local area network installation has (in addition to its conventional functions) means for storing access rules for the items of equipment connected to it. It reads a portion of each frame, which may be all or part of the destination address segment and/or of the source address segment and/or of the control segment of each incoming data frame, or it could be a frame or protocol identifier incorporated in opening bytes of the data segment. It compares the data that it reads with the stored access rules to determine whether the frame is permitted or not. If not, the repeater modifies the frame which it is in the course of re-transmitting, for example by overwriting it with meaningless digits or by encrypting it. It may also report the source address, destination address and reason for deciding to modify the frame to the network controller.

Abstract: An architecture for a synthesizer of music or other sounds which comprises an input device which supplies real time input signals indicating selected voices, a voice program memory which stores voice programs for respective voices, and a sound processing module including an array of digital signal processors, which is coupled to the input device and the voice program memory, and responsive to real time input signals to execute a group of voice programs in the voice program memory to generate selective voices in real time. Resources coupled to the input device and the voice program memory dynamically assign voice programs for selected voices to the group of voice programs in response to the real time input signals. Further, resources are available for replacing a particular voice program in the group with a voice program for a selected voice in response to the real time input signals.

Abstract: Phase-locking means are provided for synchronizing the pulse timing of two (or more) passively mode-locked pulsed lasers. The phase-locking is carried out at a frequency much higher than that of the fundamental repetition rate of the lasers because it results in much higher sensitivity. The signal from the two bandpass filters is applied to a phase detector. A phase-locked loop circuit ("PLL") is employed to generate an error signal which is applied to a piezoelectric transducer ("PZT") attached to a mirror in one of the laser cavities. Corrections in the position of the mirror driven by the error signal help reduce the effects of phase noise in the relative fundamental repetition frequencies of the two lasers so that they are effectively synchronized with one another with a "jitter" of less than 1 ps.

Abstract: A synchronously pumped optical parametric oscillator (OPO) using a temperature-tuned 90.degree. phase matched LBO crystal is disclosed which provides a broad selection of output wavelengths. A Ti:Sapphire pump source having a cavity length matched to the OPO cavity length pumps a cavity with an LBO crystal located at the cavity waist of the cavity mode.