What is the computational notion of "implementation"? It is not individuation, instantiation, reduction, or supervenience. It is, I suggest, semantic interpretation. This document is Technical Report 97-15 (Buffalo: SUNY Buffalo Department of Computer Science) and Technical Report 97-5 (Buffalo: SUNY Buffalo Center for Cognitive Science). 1 INTRODUCTION Consider the relationships among algorithms, computer programs, and the computers that execute them. An algorithm is (roughly) a procedure for computing a function (for more details, see Soare 1996; Rapaport, forthcoming). A program is a more specific and detailed textual expression of an algorithm, expressed in a programming language. Often, it is said that the program "implements" the algorithm. A computer process is an algorithm being executed (see Rapaport 1988, 1995; Smith 1997). It is a physical device (a computer) behaving in a certain way ; the way is described (or specified) by the program, and the physical device running the ...

The Origin 2000 is a high performance computing platform produced jointly by Silicon Graphics / Cray. This scalable shared memory processor (SSMP) may be configured with up to 128 processors in a single system image. The Origin is a scalable, cache coherent, non-uniform memory access (CC-NUMA), distributed shared memory (DSM) architecture based on a hypercube interconnection topology. Effectively exploiting the parallel processing capabilities of this computer, as well as other similar computers, is very much an emerging technology. The objective of this paper is to demonstrate how this parallelism may be employed on practical computing problems, using the C programming language. This paper is targeted towards software engineers who are moving from traditional single processor computers to a high performance parallel computing platform. Section 1 - Background in Parallel Processing Parallel processing is a computing technique designed to improve the execution time of an application by...