CDC Cyber

Data General MV/4000 + fpa AOS/VS f77 optimized CDC Cyber 205, Scalar Program VSOS/FTN-200 impl.vect. opt. CDC Cyber 205, Minimal Explicit Vectorization... 

Mathematical models require computation to secure concrete predictions. Successes in relatively simple cases spurs interest in more complex situations. Somewhat specialized computer hardware and software have emerged in response to these demands. Examples are the high-end processors with vector architecture, such as the Cray series, the CDC Cyber 205, and the recently announced IBM 3090 with vector attachment. When a computation can effectively utilize vector architecture, such machines will out-perform even the most powerful conventional scalar machine by a substantial margin. Such performance has given rise to the term supercomputer. ... 

The central processor (CP) time is based on a CDC Cyber 73 computer. 

An earlier Fortran version of SIMCA is available for use in the ARTHUR package available from Chemical Information Systems, Box 2227, Falls Church, VA. Recently, the operating system was changed on the CDC Cyber computer system at the University of Illinois. The new operating system does not allow the earlier SIMCA-2T version used to perform the environmental analyses to operate correctly. The authors expect that a new version of SIMCA will be installed that will function with the current operating system in use on the CDC Cyber computer. 

The mathematical models of the reacting polydispersed particles usually have stiff ordinary differential equations. Stiffness arises from the effect of particle sizes on the thermal transients of the particles and from the strong temperature dependence of the reactions like combustion and devolatilization. The computation time for the numerical solution using commercially available stiff ODE solvers may take excessive time for some systems. A model that uses K discrete size cuts and N gas-solid reactions will have K(N + 1) differential equations. As an alternative to the numerical solution of these equations an iterative finite difference method was developed and tested on the pyrolysis model of polydispersed coal particles in a transport reactor. The resulting 160 differential equations were solved in less than 30 seconds on a CDC Cyber 73. This is compared to more than 10 hours on the same machine using a commercially available stiff solver which is based on Gear s method. 

The CRAY-1 vector processing computer at the Science Research Council s (S.E.R.C) Daresbury Laboratory, is at the centre of a network providing large scale computational facilities for Universities in the United Kingdom. This is the only supercomputer available at present to Quantum Chemists in the U.K., and this article will therefore be restricted to experience gained on the CRAY-1, although this experience will undoubtedly be relevant to future applications on machines such as the ICL Distributed Array Processor (DAP) (see reference (2) for a detailed description) and the CDC Cyber 203/205. 

Wfe now aim to compute the G-matrix 64 elements at a time (this is the optimum for the CRAY, an appropriate vector length for the CDC CYBER 205 would be the size of the G-matrix). We now order the P Supermatrix so that the first 64 elements are Pi-6 wl the second 64 are Pi-6 /2 until all kfc indices are exhausted, when comes P65 128rlt >65-128/2 etc. This ordering permits us to evaluate 64 elements of the G-matrix at a time, where each ki pair index gives rise to the equation... 

The computer time for simulating 50 hours of deactivation was 13 seconds for the one-dimensional model and 15 seconds for the two-dimensional model on the CDC Cyber 174 (13). 

K bytes of memory, maintaining the dimension of 70 x 70 arrays. The extended version of the program for CDC CYBER computers, Gaussian 76, may also accommodate d-functions. As in Gaussian 70, certain standard basis sets such as e.g. ST0-3G, 4-31G and 6-31G are stored internally for easy use. 

The nonlinear algebraic equations represented by equations (6), (7), (8) were generated and solved on a CDC CYBER 74 computer. Solutions typically took 4-5 iterations to converge to an order of 10 , and for the 440 equations cited in Figure 4 each iteration took approximately 7 seconds. 

The CSDW calculations described above require substantial computer resources. A description of the algorithms and structure of the five programs that comprise the CSDW suite can be found in Ref. [16], which also reports the effect of basis set variation on CPU times for CDC 76(X), CDC Cyber 176, CDC Cyber 205, Cray X-MP and Cray-2 computers. 

An earlier implementation of the CASTOR system on a CDC-Cyber computer system, using the CDC-IMF-facihty (formerly EDMS) had proven the practical applicability of the underlying theory as well as the usability of the ancillary systems, e.g., data capture and conversion, semi-automatic addition of by-products, paphical output. The database model of EDMS was CODASYL-based. Our implementation, however, used the hierarchical components, e.g., the member-owner construct, for the sole purpose of data storage optimisation. The main parts used a relational model. The relational model became dominant in an ADABAS implementation, where member-owner sentences were replaced by dynamic field constructs. The present goal of development is a purely relational implementation under a portable relational DBMS. 

The simulation of growing cracks with a degenerating framework requires a full geometrical and physical nonlinear static analysis of the system. A vector computer CDC Cyber 205 provides the computing power required here to solve problems also with large system sizes. All FEM algorithms have been adapted for the vector computer to utilize its computing speed in an optimal way 111. 

The "Bochum Method" has been developed for delineating material structure to a 3D-framework model, calculated in its behaviour up to the totally collapsed system by a vector computer CDC Cyber 205. 

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