Back in the day, when there were no such things as mountain bikes, good bike frames had a braze-on on the underside of the top tube called a "pump peg," and pumps were designed with a hole in one end (to fit the peg) and a spring inside to force the other end of the pump against the seat tube. Such was the "frame pump."

As far as I can tell, the term has lost its meaning today, since it's come to mean any pump that can be mounted in any way to a frame, including using a mounting bracket and the bottle-cage mounts. You can still buy true frame pumps, like the Zefal hpx, and occasionally you even see a new bike with a pump peg. So I guess the world hasn't gone completely to Hell.

RichC