FORTRAN language statements

FORTRAN statements also can be inserted by the user in the paragraph called FORTRAN. Using the DEFINE sentence, as before, any problem variables may be accessed. Using FORTRAN language, any arbitrary transformation of the problem variables may be made and stored. This extremely flexible capability allows the user to (1) modify block calculations, (2) change stream values, (3) insert user FORTRAN blocks, and (4) execute many other powerful, specific functions. A BEFORE or AFTER statement can be used to make the FORTRAN execution before or after any block. 

Unlike most modem computer programs, the Herman-Skillman code, written in the FORTRAN language, uses formatted input and output statements. Thus the white spaces in the text lines of input count to separate each input parameter. 

This bottleneck can be relieved by writing the equations of formation and destruction for each species in full. Doing this by hand would be far too time consuming, and so this subroutine is written by computer. OBLOAD is an equation "hard-wirer", which automatically produces such FORTRAN code for the subroutine DIFFUN, required by GEAR (Nejad, 1986). This produces up to 3000 lines of FORTRAN in 5 minutes on a current scientific workstation computer. DBLOAD takes account of the various terms listed above, and also restrictions imposed by the FORTRAN language, such as length of line and number of continuation lines allowed in one statement. 

Statements. Most statements, except where noted otherwise, begin in the seventh column of a page considered to be 80 columns w ide continuation linen are indicated by a + (symbol may vary with version of language) in the sixth column. The first five columns are reserved for labels (line numbers), which are only required if the line is referenced by another statement, and for comment lines, which are determined by a character in the first column. Columns 7 to 72 are reserved for statements 7.S-80 are not read. (See Table 1-24 for required order of statements in FORTRAN.)... 

The DATATRAN application language processor operates within the SCOPE operating system on the CDC 6600 and 7600 machines. It consists of six major components, each designed to perform a specific data management or executive system function all are written primarily in FORTRAN, but rely on assembly language routines for character manipulation and efficient input-output operations. The components and their associated system functions are the precompiler which scans each statement in the DATA-TRAN input stream and translates it, if necessary, into an acceptable FORTRAN statement the interpreter which contains the run-time routines to execute the DATATRAN statements, creates and maintains the system s... 

To meet these conditions a special chemical programming language CHMTRN (Chemical Translator) was developed. By use of a special assembler - TBLTRN (Table Translator, written by Dr. Donald E. Barth), it was possible to convert the CHMTRN tables into specially encoded FORTRAN BLOCK DATA statements which could be loaded with LHASA or read in at run time. 

FORTRAN, the most widely used language at that time, used a complicated format control statement for all input or output in the program, a requirement too complicated for most students, particularly for those not taking science or engineering. 

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