I wrote a lot of F77 code way back when, including an 8080 simulator similar to that written by Gates and Allen used to build their BASIC for Altair. I don't know what language they wrote theirs in, but mine was pretty readable, just a bit late. And it was very portable - Dec10, VAX, IBM VM/CMS with almost no changes.
I think F77 was a pretty well designed language, given the legacy stuff it had to support.