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70 Views 0 Replies Latest reply: May 14, 2020 11:52 AM by Lynn Grant RSS
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May 14, 2020 11:52 AM

Historical FORTRAN

When I was in Engineering school in the early 1970s, I ran into an old Masters thesis in the library. It dealt with calculating the bending of truck frames under load, using an IBM 650 computer. For the benefit of interested readers, an appendix had a listing of the program. It was page after page of numbers, not even assembly language, but IBM 650 machine code.

 

I recently ran into the Programmer's Reference from 1957 for the first FORTRAN compiler, running on the IBM 704:

 

https://www.fortran.com/FortranForTheIBM704.pdf

 

Looking at it, I keep thinking of how absolutely thrilling it must have been to engineers and scientists to be able to code their programs using equations similar to what they used on paper, rather than having the distraction of becoming assembly-language programmers in order to solve their problems.

 

FORTRAN was so well received that it was ported to the IBM 650, a machine that was barely up to the task, as a reduced version that implemented 12 of FORTRAN's 32 instructions, and had severe restrictions, such as limiting statements to columns 1 through 36 of the punch card.

 

http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/650/29-4047_FORTRAN.pdf

 

Modern versions of Fortran have deleted a few of the original statements, but a few statements never made it past the first few FORTRAN compilers, such as the FREQUENCY statement, which let you give the compiler hints about how often each of the three branches in an arithemetic IF would be taken, the SENSE LIGHT i statement, which turned on lights on the front panel of the computer, and the IF (SENSE SWITCH i) statement, that branched based on front-panel switches.

 

And 50+ years later, Fortran is still with us, with 50 years of improvements, 50 years of institutional knowledge among engineers and scientists, and 50 years of shared code, such as BLAS and LAPACK, that has improved along with the language.

 

That is a wonderful thing.

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