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DAP FORTRAN
DAP FORTRAN was an extension of the non IO parts of FORTRAN with constructs that supported parallel computing for the ICL Distributed Array Processor (DAP). The DAP had a Single Instruction Multiple Data (SIMD) architecture with 64x64 single bit processors. DAP FORTRAN had the following major features: * It had matrix and vector operations. * Assignments could be performed under a logical mask so only some elements in the target of an assignment were changed. * On the negative side - operations were performed using the size of the underlying hardware i.e. on a 64x64 matrix or 64 element vector. In a declaration either one or two extents could be omitted as in: C Multiply vector by matrix REAL M(,), V(), R() R = SUM(M*MATR(A)) C Converge to a Laplace potential in an area REAL P(,), OLD_P(,) LOGICAL INSIDE(,) DO 1 K = 1, ITERATIONS OLD_P = P P(INSIDE) = 0.25*(P(,+)+P(,-)+P(+,)+P(-,)) IF (MAX(ABS(P-OLD_P)) .LT. EPS) RETURN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Computing
Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling.S.V. Adve ''et al.'' (November 2008)"Parallel Computing Research at Illinois: The UPCRC Agenda" (PDF). Parallel@Illinois, University of Illinois at Urbana-Champaign. "The main techniques for these performance benefits—increased clock frequency and smarter but increasingly complex architectures—are now hitting the so-called power wall. The computer industry has accepted that future performance increases must largely come from increasing the number of processors (or cores) on a die, rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICL Distributed Array Processor
The Distributed Array Processor (DAP) produced by International Computers Limited (ICL) was the world's first commercial massively parallel computer. The original paper study was complete in 1972 and building of the prototype began in 1974. The first machine was delivered to Queen Mary College in 1979. Development The initial 'Pilot DAP' was designed and implemented by Dr Stewart F Reddaway with the aid of David J Hunt and Peter M Flanders at the ICL Stevenage Labs. Their manager and a major contributor was John K Iliffe who had designed the Basic Language Machine—he is well known nowadays for Iliffe vectors. The ICL DAP had 64×64 single bit processing elements (PEs) with 4096 bits of storage per PE. It was attached to an ICL mainframe and its memory was mapped into the mainframe's memory. Programs for the DAP were written in DAP FORTRAN which was FORTRAN extended with 64×64 matrix and 64 element vector primitives. DAP Fortran compiled to an assembly language called APAL (A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single Instruction Multiple Data
Single instruction, multiple data (SIMD) is a type of parallel computer, parallel processing in Flynn's taxonomy. SIMD can be internal (part of the hardware design) and it can be directly accessible through an instruction set architecture (ISA), but it should not be confused with an ISA. SIMD describes computers with multiple processing elements that perform the same operation on multiple data points simultaneously. Such machines exploit Data parallelism, data level parallelism, but not Concurrent computing, concurrency: there are simultaneous (parallel) computations, but each unit performs the exact same instruction at any given moment (just with different data). SIMD is particularly applicable to common tasks such as adjusting the contrast in a digital image or adjusting the volume of digital audio. Most modern Central processing unit, CPU designs include SIMD instructions to improve the performance of multimedia use. SIMD has three different subcategories in Flynn's taxonom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALGOL-68
ALGOL 68 (short for ''Algorithmic Language 1968'') is an imperative programming language that was conceived as a successor to the ALGOL 60 programming language, designed with the goal of a much wider scope of application and more rigorously defined syntax and semantics. The complexity of the language's definition, which runs to several hundred pages filled with non-standard terminology, made compiler implementation difficult and it was said it had "no implementations and no users". This was only partly true; ALGOL 68 did find use in several niche markets, notably in the United Kingdom where it was popular on International Computers Limited (ICL) machines, and in teaching roles. Outside these fields, use was relatively limited. Nevertheless, the contributions of ALGOL 68 to the field of computer science have been deep, wide-ranging and enduring, although many of these contributions were only publicly identified when they had reappeared in subsequently developed programming lang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cray
Cray Inc., a subsidiary of Hewlett Packard Enterprise, is an American supercomputer manufacturer headquartered in Seattle, Washington. It also manufactures systems for data storage and analytics. Several Cray supercomputer systems are listed in the TOP500, which ranks the most powerful supercomputers in the world. Cray manufactures its products in part in Chippewa Falls, Wisconsin, where its founder, Seymour Cray, was born and raised. The company also has offices in Bloomington, Minnesota (which have been converted to Hewlett Packard Enterprise offices), and numerous other sales, service, engineering, and R&D locations around the world. The company's predecessor, Cray Research, Inc. (CRI), was founded in 1972 by computer designer Seymour Cray. Seymour Cray later formed Cray Computer Corporation (CCC) in 1989, which went bankrupt in 1995. Cray Research was acquired by Silicon Graphics (SGI) in 1996. Cray Inc. was formed in 2000 when Tera Computer Company purchased the Cray Rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Programming Languages
Concurrent computing is a form of computing in which several computations are executed '' concurrently''—during overlapping time periods—instead of ''sequentially—''with one completing before the next starts. This is a property of a system—whether a program, computer, or a network—where there is a separate execution point or "thread of control" for each process. A ''concurrent system'' is one where a computation can advance without waiting for all other computations to complete. Concurrent computing is a form of modular programming. In its paradigm an overall computation is factored into subcomputations that may be executed concurrently. Pioneers in the field of concurrent computing include Edsger Dijkstra, Per Brinch Hansen, and C.A.R. Hoare. Introduction The concept of concurrent computing is frequently confused with the related but distinct concept of parallel computing, Pike, Rob (2012-01-11). "Concurrency is not Parallelism". ''Waza conference'', 11 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIMD Computing
Single instruction, multiple data (SIMD) is a type of parallel processing in Flynn's taxonomy. SIMD can be internal (part of the hardware design) and it can be directly accessible through an instruction set architecture (ISA), but it should not be confused with an ISA. SIMD describes computers with multiple processing elements that perform the same operation on multiple data points simultaneously. Such machines exploit data level parallelism, but not concurrency: there are simultaneous (parallel) computations, but each unit performs the exact same instruction at any given moment (just with different data). SIMD is particularly applicable to common tasks such as adjusting the contrast in a digital image or adjusting the volume of digital audio. Most modern CPU designs include SIMD instructions to improve the performance of multimedia use. SIMD has three different subcategories in Flynn's 1972 Taxonomy, one of which is SIMT. SIMT should not be confused with software thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
