Abstract: A frequency synthesizer of the phase locked loop type and particularly useful for frequency hopping applications includes means (8) for achieving fast frequency and phase lock. In one embodiment the synthesizer is steered to a new frequency value by a DAC 10 which controls a VCO (5) input voltage. Subsequently, the phase of the synthesizer output is locked to that of the reference frequency oscillator (1) by resetting the feedback frequency divider (6) at the point in time when a rising edge of the reference frequency is detected. In a second embodiment, rapid frequency and phase lock is achieved by resetting the feedback frequency divider (6) on every rising edge of the reference frequency while the feedback loop is disabled, until the detected phase difference between the reference frequency and the divided VCO frequency reaches a minimum value.

Abstract: A multiple application switching platform includes a switch having a distributed open architecture and incorporating redundancy for enhanced fault tolerance. The switch includes at least one shelf having a midplane (1) containing message buses and TDM data buses (A and B). Shelves may be interconnected to form a group wherein various circuit cards are connected to each shelf midplane. The circuit cards (4, 5 and 6) perform call processing wherein each card within a group accessing a data bus is pre-assigned a unique set of time slots for each data bus within which that card may transmit onto that data bus. Each circuit card further includes an identification number that enables each card an opportunity to transmit onto a message bus (A and B). The circuit cards (4, 5 and 6) include line or trunk switch cards that function as an independent switch to interface line or trunks to a shelf midplane.

Abstract: A method and system for compensating for thermally-based frequency fluctuations of a piezoelectric crystal. A characterization of the frequency-temperature response of the crystal is stored in a memory. During operation, a host system is provided with the crystal's uncompensated frequency, the temperature of the crystal, and frequency correction values stored in the memory. The host system may then determine a compensated frequency by retrieving, or deriving through interpolation, a frequency correction value from the data provided in the memory.

Abstract: A storage server for efficiently retrieving data from a plurality of disks in response to user access requests. The server comprises a plurality of processors coupled to disjoint subsets of disks, and a custom non-blocking packet switch for routing data from the processors to users. By tightly coupling the processors to disks and employing an application-specific switch, congestion and disk scheduling bottlenecks are minimized. By making efficient use of bandwidth, the architecture is also capable of receiving real-time data streams from a remote source and distributing these data streams to requesting users. The architecture is particularly well suited to video-on-demand systems in which a video server stores a library of movies and users submit requests to view particular movies.

Abstract: A storage server for efficiently retrieving data from a plurality of disks in response to user access requests. The server comprises a plurality of processors coupled to disjoint subsets of disks, and a custom non-blocking packet switch for routing data from the processors to users. By tightly coupling the processors to disks and employing an application-specific switch, congestion and disk scheduling bottlenecks are minimized. By making efficient use of bandwidth, the architecture is also capable of receiving real-time data streams from a remote source and distributing these data streams to requesting users. The architecture is particularly well suited to video-on-demand systems in which a video server stores a library of movies and users submit requests to view particular movies.

Abstract: Y is O or S;R.sup.1 is hydrogen, halogen, C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy;R.sup.2 is hydrogen, halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.2 -C.sub.4 alkenyl, C.sub.2 -C.sub.4 alkenyloxy, C.sub.2 -C.sub.4 alkynyl, C.sub.2 -C.sub.4 alkynyloxy, mono-, di- or tri-halomethyl, trifluoromethoxy, C.sub.2 -C.sub.4 alkylthio, C.sub.3 -C.sub.4 branched alkylthio, nitro, or cyano;R.sup.3 is hydrogen, halogen, methyl, mono-, di- or tri-halomethyl;R.sup.4 isa) C.sub.3 -C.sub.8 cycloalkyl substituted by one or more C.sub.1 -C.sub.4 alkyl, preferably one or two methyl;orb) ##STR2## wherein R.sup.6 and R.sup.7 are independently, hydrogen or linear or branched, C.sub.1 -C.sub.4 alkyl, C.sub.2 -C.sub.4 alkenyl, or C.sub.2 -C.sub.4 alkynyl, and R.sup.8 is C.sub.3 -C.sub.8 cycloalkyl substituted by one or more C.sub.1 -C.sub.4 alkyl; andR.sup.5 is an acyclic or cyclic side chain as defined herein.These compounds are useful for inhibiting the growth or replication of retroviruses such as HIV.

Abstract: A method of inhibiting the growth or replication of viruses of the HIV group is disclosed. Also disclosed are compounds useful in the method and pharmaceutical formulations incorporating such compounds. The method involves the use of compounds having the general formula: ##STR1## wherein the substituent groups are as defined in the specification.