Years ago I fellow advertised a tenon cutting set-up that attached to a Woodmizer sawmill frame. This would allow a timber framer to place his timber on the sawmill bed and slide the tenon cutter over the timber and cut a tenon on the either end.
If you owned a sawmill you could buy just the sliding carriage, or if you didn't own one you could buy the hole machine.
Also, I've seen pictures of shops where they set-up two radial arm saws in the same line or plane. One was fixed and the other slide on a track to allow you to move it for different length timbers. Each radial arm saw could be set-up with either a saw blade for cutting off the timber or a dado saw head for hogging out wood forming the sides of tenons.
Jim Rogers