\noindent {\bf Stellar GS1000 } \noindent {\bf Vector Register, Shared-Memory, Parallel Architecture - graphics supercomputer } \vspace{.1in} \noindent {\bf Architecture:} Custom-designed Application-Specific Integrated Circuits (ASICs) are used both for processor and graphics hardware. There are 11 distinct modules with approximately 2 million 1.5 $\mu$ CMOS gates in 61 physical components. Silicon is fabricated by LSI Logic foundry in California, and boards are assembled by TI in Tennessee. \vspace{.1in} \noindent A central feature of this computer is its DataPath architecture which acts as a switch and multiplexor/demultiplexor rather than a conventional bus. The main processing unit, the SPMP (Synchronous-Pipeline Multiprocessor) is a custom multi-stream architecture providing up to four instruction-execution streams. Streams share functional units, on a pipelined basis, and each has its own large register files with dedicated integer, scalar floating-point, and vector floating-point registers. The clock cycle time is 50 nsec. The multi-stream processor (MSP) is implemented as a single unit thus enabling 100 nsec synchronization through concurrency registers within the MSP. The four streams of the MSP are interleaved onto a single 12-stage MSP pipeline. In the steady state, an instruction finishes on every cycle, for an instruction throughput of 20 mips. Note that each stream is completing an instruction every 200 nsec because of the length of the pipes. The use of a technique called packetization, whereby a single stream can execute 2 non-conflicting instructions simultaneously, can increase the performance to 25 mips. \vspace{.1in} \noindent In addition to the multi-stream processor, there is a special-purpose functional unit for scalar and vector floating-point instructions using Weitek 2264/2265 chips. \vspace{.1in} \noindent Minimum main memory is 16 Mbytes expandable to 128 Mbytes with a data transfer rate of 320 Mbytes/sec and a memory bandwidth for graphical operations of 640 Mbytes/sec (possible because pixel data is accessed in 128 rather than 64 byte blocks). Memory cycle time is 200 nsec. All four streams share a single 1 Mbyte static RAM cache, thus avoiding the coherency problems of multiple cache machines. The cache line is 64 bytes, and one line can be accessed every clock cycle for a transfer rate of 1.28 Gbyte/sec. \vspace{.1in} \noindent The Main Data Path also manages DMA I/O, using four I/O channels each with a capacity of 16 Mbytes/sec. Multiple controllers and disk striping are supported. \vspace{.1in} \noindent A PC-AT compatible integral Service Processor, based on a 80386 microprocessor, controls booting and console functions in addition to managing scan-path and remote diagnostic systems built into each circuit. PC-AT software can be run on the Service Processor under a window of the display. \vspace{.1in} \noindent One feature of this computer is the tight integration of general-purpose and graphical computation. Central to this is the Rendering Processor, a custom-built special-purpose SIMD engine which executes 320 million graphics-specific operations per second and implements high-level machine instructions for high-performance rendering of complex shaded and solid images, including lighting, Gouraud and Phong shading, depth-cuing, and anti-aliasing. Using virtual pixel maps, images are rendered into virtual memory which allows n-way buffering and does not restrict image size to that of the display devices. Images are transferred from main memory to the frame buffer at 640 Mbytes/sec. A 16- or 32-bit frame buffer is available which allows both hardware double-buffering and stereo viewing. An enhanced X-window system and the Programmer's Hierarchical Interactive Graphics System (PHIGS) are supported. Stellar is assisting in the development of PHIGS+ and will support these extensions to PHIGS in hardware as well as software. Main display device is a 1280 x 1024 19" color monitor running at 74 Hz. \vspace{.1in} \noindent {\bf Configuration:} The GS1000 can be used as a stand-alone machine. However, TCP/IP, NFS, and Ethernet are supported, and support is planned for ISO/OSI protocols, Pronet-80, and FDDI (Fiber Distributed Data Interface) when available or defined. 80 Mbyte hard disks, a 380 Mbyte 5 1/4 inch disk drive (with double density option at 766 Mbytes), a 600 Mbyte 8" disk drive, a 120 Mbyte cartridge tape drive, and a 1/2 inch tape drive are supported. There is support for up to three VME buses, and a PC-AT compatible bus. \vspace{.1in} \noindent {\bf Software:} The operating system, called Stellix, is based on Unix System V Release 3.1, with enhancements for multiprocessing, I/O, Berkeley 4.3, etc. \vspace{.1in} \noindent {\bf Languages available:} The Fortran-77 (with extensions) and C compilers automatically detect parallelism and use vector processing. The Fortran compiler has most of the popular VMS extensions. An execution profiler and a multi-stream symbolic debugger are available. A concurrency library is available for manual control of program concurrency. A Stellar Assembler language is available. Ada and LISP compilers are under development. \vspace{.1in} \noindent {\bf Applications:} Major applications targeted include computer-aided design and engineering, molecular modelling, computer animation, image processing, geophysical modelling, simulation and analysis, fluid dynamics, aerodynamics, astrophysics, and meteorology. Stellar has reached agreements for the porting of over 45 third-party software applications, and discussions are ongoing with over 70 application software vendors. \vspace{.1in} \noindent {\bf Performance:} Peak rates of 20-25 mips and up to 40 Mflops in double precision (64-bit words). Graphics maximum rate of 600,000 3D vectors/sec and 150,000 Gouraud shaded polygons/sec. It is planned to offer over 100 mips processing by 1990. \vspace{.1in} \noindent {\bf Status:} The cost of a configuration which includes the three processing units, 16 Mbytes of memory, a 380 Mbyte disk, cartridge and high-density floppy drives, PC/AT controller, a 1280 x 1024 monitor, and operating system is \$104,900. The parallelizing Fortran compiler costs \$4K. \noindent The first shipment was to the NIH in March 1988. European shipments commenced in June 1988. \vspace{.1in} \noindent {\bf Contact:} \begin {flushleft} Stellar Computer Inc\\ 85 Wells Ave.\\ Newton, MA 02159\\ 617-964-1000\\ \vspace{.1in} \noindent Chairman and CEO: Dr. John William Poduska, Sr.\\ President and COO: Arthur Carr\\ VP Sales: Wallace E. Smith\\ Technical Support: Timothy Stewart\\ VP International Sales: Dan Murray\\ \vspace{.1in} \noindent Ian Gilbert\\ UK Marketing and Sales\\ Little Eastwick\\ Lower Farm Road\\ Effingham, Surrey KT24 5JJ\\ England\\ 0372-58707\\ \vspace{.1in} \noindent Hans Holler\\ Germany Marketing and Sales\\ Hagenauer Strasse 42\\ 6200 Wiesbaden\\ WEST GERMANY\\ 49-61-22037 \\ \vspace{.1in} \noindent Makota Yamada\\ Japan Sales and Marketing\\ Kihoh Bldg. 1F\\ 2-2 Koji-machi\\ Chiyoda-ku\\ Tokyo, JAPAN\\ 81 3 237 0131\\ \vspace{.1in} \noindent European marketing divided into three regions centered on UK, France, and Germany.\\ \end {flushleft} .