"Firefly: A Multiprocessor Workstation."
    C. P. Thacker, L. C. Stewart, and E. H. Satterthwaite, Jr.
    December 30, 1987.  17 pages.

Authors' Abstract

    The Firefly is a shared-memory multiprocessor workstation that
    is used as the primary source of computing at the Digital Equipment
    Corporation, Systems Research Center (SRC).  Two versions of the
    Firefly have been built.  The first version contains from one
    to seven MicroVAX 78032 processors, each with a floating point
    unit and a sixteen kilobyte cache.  The caches are coherent, so
    that all processors see a consistent view of main memory. A system
    may contain from four to sixteen megabytes of storage. Input-output
    is done via a standard DEC QBus.  Input-output devices are an
    Ethernet controller, fixed disks, and a monochrome 1024 x 768
    display with keyboard and mouse. Optional hardware includes a
    high resolution color display and a controller for high capacity
    disks.  The second version of the Firefly contains faster CVAX
    78034 processors, sixty-four kilobyte caches, and a main memory
    of up to 128 megabytes.

    The Firefly runs a software system that emulates the Ultrix system
    call interface.  It also supports medium and coarse-grained
    multiprocessing through multiple threads of control in a single
    address space.  Communication is implemented uniformly through
    the use of remote procedure calls.

    This report describes the goals, architecture, implementation,
    and performance analysis of the Firefly.  It then  presents some
    measurements of hardware performance, and concludes with some
    brief remarks on the evolution of the software.