Expansion of the TFTR neutral beam computer system

Previous TFTR Neutral Beam computing support was based primarily on an Encore Concept 32/8750 computer within the TFTR Central Instrumentation, Control and Data Acquisition System (CICADA). The resources of this machine were 90% utilized during a 2.5 minute duty cycle. Both interactive and automatic processes were supported, with interactive response suffering at lower priority. Further, there were additional computing requirements and no cost effective path for expansion within the Encore framework. Two elements provided a solution to these problems: improved price performance for computing and a high speed bus link to the SELBUS. The purchase of a Sun SPARCstation and a VME/SELBUS bus link, allowed offloading the automatic processing to the workstation. This paper describes the details of the system including the performance of the bus link and Sun SPARCstation, raw data acquisition and data server functions, application software conversion issues, and experiences with the UNIX operating system in the mixed platform environment