Parallelism in random access machines

Steven Fortune and James Wyllie, Annual ACM Symposium on Theory of Computing archive
Proceedings of the tenth annual ACM symposium on Theory of computing, pp. 114–118,
San Diego, California,
[ACM Digital Library URL]

Abstract
A model of computation based on random access machines operating in parallel and sharing a common memory is presented. The computational power of this model is related to that of traditional models. In particular, deterministic parallel RAM’s can accept in polynomial time exactly the sets accepted by polynomial tape bounded Turing machines; nondeterministic RAM’s can accept in polynomial time exactly the sets accepted by nondeterministic exponential time bounded Turing machines. Similar results hold for other classes. The effect of limiting the size of the common memory is also considered.