Fred Cisin wrote about QDOS for the 8086 vs. CP/M for the 8080:
1) It was explicitly acknowledged BY PATERSON to be a
copy, although
he certainly did not copy any of the internal code. In THOSE days, it
would be called "a clean copy". 2) Under the current "taste and
smell"
level of copyright, it would indeed be considered infringing under the
cutrrent INTERPRETATIONS of the law, although not by the "did they
copy bytes?" interpretations at the time.
I don't think so. Oracle just mostly lost their multi-billion dollar
lawsuit against Google over just such an API claim. The court found
that the "structure, sequence, and organization" of an API is not
copyrightable. It remains to be seen what will happen on appeal. In a
recent similar case in Europe it was also decided that an API is not
copyrightable.
Samsung did not "copy bytes" from Apple,
but the courts recently
ruled that the similarities are infringing.
That's a patent suit, which is a whole different kettle of fish. I
think there's a good chance that Samsung will get an appeal on the basis
that the judge improperly disallowed some significant evidence.