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U.S. Department of Energy
Office of Scientific and Technical Information

Parallel problem-solving system, PRISM (Parallel Inference System). Final report, November 1986-February 1988

Technical Report ·
OSTI ID:5979582
A parallel problem-solving system, PRISM (Parallel Inference System), that was implemented on the VAX/11-780, the PYRAMID and SUN machines, was ported successfully to McMOB and then to the BBN Butterfly parallel architecture. The McMOB architecture is essentially the ZMOB architecture with 16 Motorola 68000 processors, upgrading the Z80A microprocessors, interconnected in a ring structure. Experimental testing of PRISM on McMOB was undertaken. In addition, several enhancements were made to PRISM to permit experimental analyses to be made, and to incorporate additional features to take full advantage of parallelism in a problem-solving environment. The tracing and statistical gathering packages were extended. An ability to display AND-parallelism was added to the trace program, which displays the execution of a program on the parallel machines. Heuristic techniques were developed to determine which information to display to a user. The system software for ZMOB/McMOB is now robust and considered completed. This has allowed the author to re-emphasize studies on parallel software. A new formalism for slicing/splicing was developed that eliminates much of the run-time overhead of the technique, allowing for the development of a splicing compiler. Work has also focused on the development of debugging tools for parallel software and the integration of artificial-intelligence techniques into debugging software.
Research Organization:
Maryland Univ., College Park (USA). Dept. of Computer Science
OSTI ID:
5979582
Report Number(s):
AD-A-204915/3/XAB
Country of Publication:
United States
Language:
English