FORTRAN microcomputer

Almost all applications programming in chemistry, and structural chemistry in particular, is performed in the FORTRAN language and the molecular mechanics calculations for which this hardware/software design exercise was undertaken is no exception. There are two problems which must be solved in order to build a FORTRAN microcomputer system with good scalar and array computational performance and these are firstly, the design of an efficient scalar processor with a transparent FORTRAN interface to the hardware and secondly, the design of an efficient AFPP,... 

The program can solve both steady-state problems as well as time-dependent problems, and has provisions for both linear and nonlinear problems. The boundary conditions and material properties can vary with time, temperature, and position. The property variation with position can be a straight line function or or a series of connected straight line functions. User-written Fortran subroutines can be used to implement more exotic changes of boundary conditions, material properties, or to model control systems. The program has been implemented on MS DOS microcomputers, VAX computers, and CRAY supercomputers. The present work used the MS DOS microcomputer implementation. 

Software Availability. The SIMCA software is available in two forms, both developed by Wold (25) 1) an interactive, Fortran version which runs on Control Data Corporation (CDC) machines. The second set of programs are an interactive microcomputer version, SIMCA-3B, are available from Principal Data Components, 2505 Shepard Blvd., Columbia, MO 65201. The SIMCA-3B pattern recognition programs includes the CPLS-2 program used for PLS analysis and are available for CP/M (Digital Research, Pacific Grove, CA) and MS-DOS (Microsoft Corporation, Bellueve, WA) for 8088 or 80 86 based microcomputers. 

The Fortran version used in this study was located at the Computer Center at the University of Illinois at Champaign/Urbana. The Fortran version is useful for analysis of very large data sets, i.e. 400 x 70 matrices. The SIMCA-3B version for microcomputer systems is interactive, menu driven, and is applicable to intermediate sized data sets and runs under CPM or MS-DOS. In this study, the SIMCA-3B program—CPLS-2, was used to obtain the results in the PLS examples discussed. 

V. K. Matveev, Numerical Methods in Chemistry Scientific Course Based on Microcomputers and FORTRAN, Pt. 1, MGU, Moscow, 1985. 

The author has presented details of a cost effective vector processor for use with S-100 microcomputers and produced a library of FORTRAN callable subroutines for general purpose floating point computations. Brief details of the construction of a molecular mechanics program using the vector processor have been given. 

Spread-sheet software has achieved great popularity because of its availability for microcomputers at reasonable cost, the ease of learning and using the software, and its flexible application to many problems. Solutions for many engineering problems can be obtained more rapidly by spread sheet than by writing a language code program, such as FORTRAN or BASIC. 

In the pocket in the back of this book are four simple Fortran generic codes that can be used to solve sets of linear and nonlinear equations on microcomputers or mainframes. Because these programs are simple, and thus may on occasion fell to solve your problem, you may want to use more polished computer codes that are available in your computer center software library. Such codes are more robust, but of course it takes more of your time to understand how to use them proficiently. 

FORTRAN language (FORTRAN IV, F66) could only be used on large mainframe systems that accepted programs in batch. Turnaround was slow interaction was nil. The availability of microcomputers (IBM personal computers or compatible) has made it easier for numerical techniques, simulation, and design problems to be developed. Computer software can now be used interactively on such systems. 

This book is unique in that to date no textbook on chemical process deign and simulation using microcomputers and the FORTRAN programming language has been published. FORTRAN 90 is a major development of the FORTRAN language and includes all the computer programs in this text as a subset. To assist the user and to demonstrate the validity of the methods, worked examples of practical industrial relevance are provided throughout the text. 

The second stage is data acquisition. This stage is entered when the operator starts the instrument and pushes the computer start button to initiate data collection. The data are collected at the predetermined rate on the Y, Y and T channels of the 990 console. The third stage is data transmission during which the microcomputer transmits the entire data set for the sample to the minicomputer where it is stored on disk until the operator initiates the fourth stage which is data reduction. The data reduction takes place in the minicomputer and is programmed in FORTRAN. Reports and plots are generated at this time. 

Bowles, K., Microcomputer Problem Solving Using Pascal, Springer-Verlag, New York (1979). Law, V.J., ANSI Fortran 77 An Introduction to Structured Software Design, Wm. C. Brown, Dubuque, Iowa (1983). 

---