I need help converting a code Fortran to Rstudio

See the FAQ: How to do a minimal reproducible example reprex for beginners. The code provided does not compile under gfortran due to an error on the first line and the absence of PORTLIB on the second. Because it won't compile, it can't be converted with f2c to C to see what it does. The alternative (for me at least) is turning the calendar back to 1966 and learn FORTRAN all over again.


GOTO considered harmful

@nirgrahamuk 's link is also what I'd recommend doing with FORTRAN source code.