I did a fair amount of research (not a lot, though), olePigeon.  The DMCA does not appear to contain any exception for floppy disks or vintage software, absent the exceptions I referred to above - which pertain exclusively to libraries and archives.

However, as I also mentioned above, it in theory is possible for a (library or archive) user to request, in full, an obsolete computer program - though the boundaries of such an exception are by no means hammered out clearly.