Irvine, California-based Corollary Inc has introduced a Symmetric Integrated Multiprocessor chip set for building multiprocessor Intel Corp 80586-based machines, and has won the support of Microsoft Corp, which signed Corollary to develop multiprocessing extensions for the forthcoming Windows NT operating. The set comprises the Cache Bus Controller – one per board – to provide a second-level cache controller, third-level cache, bus protocol and distributed interrupt controller, and a Data Path Exchange Chip, two required per board, which provides a 64-bit data path from the bus to the 80586 processor. Implementations of Santa Cruz Operation Inc MPX and Unix System Laboratories Inc’s Unix System V.4.0 are already complete, and the implementation of Windows NT has also been developed. An update to the C-bus II specification will be available on July 1. There is a nominal one-time fee of $500 for manufacturers that want to use the C-bus II architecture. The chips will sample in the fourth quarter. Windows NT will be a fully-fledged multi-tasking multi-user, multiprocessor operating system Citrix Systems Inc is taking care of the multi-user side (CI No 1,935). The Windows NT Hardware Abstraction Layer for C-bus II systems contains more than 3,000 lines of code and was completed in May. Microsoft will be distributing it.