[pp.int.general] Purpose of copyright

[Richard M. Stallman]

    It was 1981, the same year that the US Supreme Court issued its edict
    that software could be both copyrighted and patented. 

Actually the Supreme Court didn't really say that.
What it said was that a process for curing rubber was patentable,
and the fact that it was designed to use a computer
did not stop it from being patentable.

In 1982 an appeals court twisted this into "anything implemented on a computer
is patentable".