fixed-format Fortran sources to C. The generated C code is
designed to be human-readable and suitable for further development
including linking and to create DLLs. It is specifically designed
to use C shared variables in place of FORTRAN COMMON variables so
that it can be used to convert Real-Time Simulation Modeling
source code. Samples of original FORTRAN and converted C
source are available on request.
FtoCConvert is self
contained and easy to use in a command window or .bat file.
FtoCConvert has no
dependencies. Nothing else to download.
FtoCConvert is written
in C but doesn't require compilation.
developed by QuickReckoning, Inc.
Send questions and
comments to the email address found here -
There are "FORTRAN to C Converter" programs available
such as FABLE or FtoC
but none have been designed, nor have other authors been willing to
customize their "FORTRAN
to C Converter" product, for a specific target application
Large Real-time Simulation projects such as those required to
produce or support a full scope "Nuclear Power Plant Control Room
Simulator" rely on sharing data amongst hundreds of
modules. That's the opposite of what
C++ is designed for, i.e., C++ keeps functions and data coupled in
programming blocks referred to as objects. But the "C
programming language" allows for using either shared DLLs or
memory mapped files as a mechanism to share vast amounts of
Mike Groves, a former long time
engineer/consultant/designer/programmer in the Nuclear Power Plant
Simulator field (1978-2000), and founder of QuickReckoning, Inc. (in
1992), has developed a utility program
specifically designed to convert Real-Time Simulation model FORTRAN
source code to C source code so that the models may then be compiled
and linked using Microsoft
Visual Studio's C compiler. QuickReckoning, Inc. has dubbed it simply "FtoCConvert.exe".
Though many simulators previously running on legacy Gould Encore
computer platforms have been ported to "WINTEL" computer platforms,
the original legacy FORTRAN models have remained. Thus, the simulator
owner has had to purchase FORTRAN compilers through the
years (originally "Compaq FORTRAN" and currently "Intel
FORTRAN Compiler") as Microsoft Visual Studio has changed.
In addition, even though FORTRAN is rarely used today when compared to
other languages including the C language the requirement is that
maintenance engineers must still be knowledgeable in FORTRAN or be
Though simulator support software like
executive systems and Instructor Stations along with development utility
software such as QuickReckoning's own "Simease"
environment or others like the "GSES
are written in C or Java, the FORTRAN simulation model development and
maintenance is still
required. In regard to the legacy computer language, FORTRAN,
little has changed in the past 20 years so far as Nuclear Power Plant
modeling even though new versions of FORTRAN have been developed since
It appears as if the only reason the FORTRAN code is still
around is that 1000's of lines of
FORTRAN code have been written already and up until right now there
has been no purely automated method to convert that FORTRAN to C.
Codes such as RELAP5 for
example, were written in, and still exist only in FORTRAN. No
one has attempted to use a "FORTRAN to C Converter" program
on this code.
Maybe there has never been an interest in converting this
software because it has been considered too expensive to do so.
But why? After all, much of the code used in these simulators looks just like C code
- the constructs being very similar, the math libraries nearly
identical. By simply replacing some words like "IF"
with "if" and "DO" with "for", much of
the conversion is possible.
BUT...as with many computer programs, the last 10% of the
development takes 90% of the time. Let's not forget, after all,
that FORTRAN array subscripts begin with 1 and not ZERO as C
does. Nor should we forget that the memory layout of a C matrix
is different than that of a FORTRAN matrix. If we want to use
our existing Initial Condition files to "reset" our simulator, then
our C code must take this matter into consideration. The point
being that there are facets of FORTRAN programming not immediately
translated to C. However, FtoCConvert.exe takes all these issues
into account to deliver a "FORTRAN to C Converter" program
specifically written to target Nuclear Power Plant Simulator projects.
With no desire to update our systems with the latest Intel
FORTRAN offering, we undertook the challenge to write a utility that
would take as input the original FORTRAN simulation subroutines and
functions source files and automatically convert them to compilable C
source files. The conversion looks almost identical except with
C constructs swapped in for the FORTRAN along with lots of
";" (end of line characters) and "[" "]"characters
(array index characters).
To test our FtoCConvert.exe "FORTRAN to C Convert" program we converted 1000's of lines of
code associated with a Nuclear Power Plant Simulator as those codes
existed in 1999. The resultant C code then compiled, and linked
cleanly. The resultant simulator then cycled without
mathematical error using
exactly the same Initial Conditions as those used under the FORTRAN
We suspect that our resulting nuclear power plant simulator,
previously written with 100% of its models in FORTRAN, is the first to
run by converting those FORTRAN models with C source code. In other
words, the Microsoft
Visual Studio projects previously inclusive of FORTRAN source code
were entirely replaced by those running the converted C source files.
For more information about FtoCConvert.exe ("FORTRAN to C
Converter") which is specifically
tailored and supportive of the Nuclear Power Plant Simulation Industry
contact QuickReckoning using the information found here: