Autonet is a self-configuring local area network composed of switches interconnected by 100 Mb/s, full-duplex, point-to-point links. The switches contain 12 ports that are internally connected by a full crossbar. Switches use cut-through to achieve a packet forwarding latency as low as 2 ms/switch. Any switch port can be cabled to any other switch port or to a host network controller. A processor in each switch monitors the network's physical configuration. A distributed algorithm running on the switch processor computes the routes packets are to follow and fills in the packet forwarding table in each switch. With Autonet, distinct paths through the set of network links can carry packets in parallel, allowing many pairs of hosts to communicate simultaneously at full link bandwidth. A 30-switch network with more than 100 hosts has been the service network for Digital's Systems Research Center since February 1990.>

The Firefly shared-memory multiprocessor workstation system consists of from one to nine VLSI VAX processors, each with a floating-point accelerator and a cache. The caches are coherent, so that all processors see a consistent view of main memory. The Firefly runs a software system (Topaz) that emulates the Ultrix system call interface, and in addition provides support for multiprocessing through multiple threads of control in a single address space. Communication is provided uniformly through the use of remote procedure call. The authors describe the goals, hardware, software system, and performance of the Firefly, and discuss the extent to which the development has been successful in providing software to take advantage of multiprocessing.>

Abstract The design of an integrated programming and debugging system using the language ALGOL W is described. The debugging tools are based entirely upon the source language but can be effeciently implemented. The most novel such tool is a selective trace, automatically controlled by execution frequency counts. System performance information is included.