Irvine, California-based Corollary Inc has expanded its multi processor hardware and software offerings with the 386/smp shared memory multiprocessor subsystem, designed to provide OEM customers with a binary-compatible upgrade path for 80386-based personal computers. Corollary first upgraded its 80286-based ATtain multiprocessing technology to the 80386 at UniForum last year, offering support for up to four processor modules, but later in the year was revealed as the company behind Zenith Data Systems’ multi-processor 80386 Z-1000 box, unsuccessfully bid for the Air Force AFCAC 251 project – that was won by AT&T. Zenith used an upgraded version of the ATtain technology using 25MHz 80386s to produce a 15 MIPS, 64-user system, and Corollary later introduced its own version, the six processor ATtack system. At UniForum, the company’s 386/smp is a further extension, allowing up to 10 processor modules with 64Mb memory to be used. The system includes the proprietary 64Mbyte-per-second C-bus for processor and memory traffic alongside a standard AT-bus for peripherals, up to 10 386 processor boards, memory and operating system software. The modular design will allow for evolution from AT to EISA bus in the future, according to Corollary. The operating system, based on SCO Xenix, has an extended multiprocessor kernel modified by Corollary under licence from the Santa Cruz Operation: it overlays the standard kernel and is binary compatible, allowing off-the-Unix and Xenix applications to run unchanged. Symmetrical multiprocessing is achieved by dynamically allocating user programs and system code to all available processors, while the software detects the number of processors and spreads the load among them. Each CPU has an independent 64Kb write-back cache, and one processor remains an AT-compatible computer, allowing existing I/O driver code to be run without change. OEM prices for a typically configured core system start at under $10,000.
