R. F. DeMara and D. I. Moldovan, "Marker-Passing on a Parallel Knowledge Processing Testbed," in Proceedings of the First International Conference on Parallel and Distributed Information Systems (PDIS'91), pp. 180, Miami, Florida, U.S.A., December 4 - 6, 1991. Abstract: We have been experimenting with knowledge representation and reasoning mechanisms suitable for parallel computation. Our primary domain is Natural Language Understanding(NLU) using a semantic network representation and parallel marker-passing techniques. We have implemented a multiple processors called Semantic Array Network Processor(SANP-1) for real time processing of moderately- size knowledge bases.