Impressive developments in distributed systems indicate that in the 1990s workstations will play an even more crucial role than they do now in enhancing the productivity of engineers and scientists. At present the market for such products is dominated by US companies, and Japan shows growing interest in competing in this area. Europe lags significantly behind. The EuroWorkstation (EWS) project aims to provide a competitive European response by the early 1990s: the industrial partners within the EWS project are committed to bringing EWS machines to the market.
EWS is based upon an open modular architecture. Modularity is provided at three different levels: shared memory, communication bus and local area networks. This hierarchy allows appropriate trade-offs to be made between cost and performance. Shared memory is used for high-performance communications such as, for example, numerical applications where scalar and vector processing interfere. A communication bus is used for more autonomous coprocessors, where special efforts are invested in message-based communication mechanisms.
The EWS project proposes to introduce the LIW concept at the workstation level. This concept is an extension of the RISC principle, since it can increase the number of instructions per cycle. Moreover, such techniques are very much in use for microcode purposes in current supercomputers and accelerators (FPS, NUMERICS, etc). Performance gains can be achieved by two main independent measures: a reduction in cycle times in proportion to finer feature sizes, with associated lower gate delays; and special (parallel) architectures tailored to a relatively small range of applications.
RISC and possibly VLIW approaches limit the design effort involved in producing these custom architectures. If a modular workstation provides a standard coprocessor communication system (CCS), performance can easily be boosted by adding special coprocessor boards according to the needs of the user. All that is required from the coprocessor is adherence to the CCS standard; its internal architecture can be derived from and optimised for the application area.
The operating system (OS) of the workstation needs to be distributed to allow uniform and efficient sharing of the specific resources provided by the specialised coprocessor boards. Since the OS which serves as a basis for the EWS is designed to support task distribution over a LAN, it needs to be especially optimised to take advantage of the closer coupling of the heterogeneous hardware components within the workstation provided by the system bus. The OS will therefore be based on a message-passing service (the CCS), taking advantage of the facilities provided by the hardware bus (Multibus II) and providing interprocess communication facilities for easy cooperation of user processes being executed on the various components of the workstation. The EWS workstation will comply with existing communication standards (OSI and INTERNET). File sharing, remote execution and printing, and access to other equipment and sites will be provided.
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