(I know of
some done in 1975, from an IBM
mainframe to a DG Nova.)
At least as early as 1965 IBM sold equipment that could do this, so
I rather imagine people probably did binary transfers even in those days,
but I don't have any proof of it.
Well, modems predate computers, so "first" is probably not a great word
to use.
William Donzelli
aw288(a)osfn.org