Sun Microsystems Inc has turned the MBus and Version 8 of its hardware blueprints over to Sparc International to spur a high-volume inexpensive Sparc-based multiprocessor business among builders of Sparc machines compatible with its own. Sparc International will publish the Sparc Architecture Version 8 specification and make it freely available through technical bookstores and universities worldwide in the next few days. The specification, which of necessity maintains binary compatibility with previous revisions, includes a precisely defined memory model that will simplify converting uniprocessor applications to run in multiprocessor environments. Sparc International will also distribute the misleadingly named MBus specification. The MBus is not a bus at all in classic engineering terms but rather a multi-chip module interface designed to provide a common high-performance interconnect standard for all Sparc processors, cache, memory and input-output functions. Both Sun and Sparc International, which was charged with licensing Sparc technology to third parties last year, are anxious to have it identified as the time-to-market technology, they said. The MBus will reportedly make it easier for third parties to swap chips in and out and upgrade their systems more quickly, moving to next-generation MBus-compatible chips, such as the superscalar Sparcs expected later this year, without fretting over hardware redesign, compatibility and debug issues. It will also give them more room to innovate and add value. Sun Laboratories’ director of advanced systems Dave Ditzel, called MBus the world’s first instance of multiple generations of chips using the same pin-out standard. Sparc International and its members-composed Architecture Committee are now responsible for the future evolution of both the version 8 and MBus Level I (uniprocessor) and Level II (Multiprocessor) specifications. Companies that have had a hand in reviewing Version 8 over the last year include Floating Point Systems Inc and Amdahl Corp. These standardisation efforts, unapproached at this level anywhere, will give Sun and its camp another brickbat to throw at their rivals, particularly the new ARCA group led by Microsoft Corp, Compaq Computer Corp, MIPS Computer Systems Inc and Digital Equipment Corp.
