If you took arbitrary fortran, especially with i/o, the results were an unreadable mess - but they compiled and ran. For a project I had (in the early 90s iirc

If you took arbitrary fortran, especially with i/o, the results were an unreadable mess - but they compiled and ran. For a project I had (in the early 90s iirc), I had to extensively modify the fortran and make multiple versions before the generated C was readable. Still, much easier than a rewrite.