I believe free format came about in Fortran 90, and that FORTRAN 77 was still fixed format--at least that's what a quick Google suggests. But even still, fixed-format F77 has stuck around in lots of legacy code bases for a long time. We only migrated one of our large codebases to free format a few months ago.
I learned Fortran IV and later Fortan 77 in the mid eighties and programmed professionally in Fortran 77 up until 2000. I was taught and programmed with fixed format. I believe that there may have been compiler switches to allow non-fixed format. I'm pretty sure that longer lines were allowed via a compiler switch.
I am still writing new code in fixed format. Because of the wonderful compatibility, I can do it while using a lot of new features from the recent standards which are both supported in GNU Fortran and Intel Fortran. You can call me old school, but I like the constraint of the line length in fixed format, it helps me writing clean code and reduce the "double" loops in my algorithms.
