This detail from a 15th century painting ( the Coronation of the Virgin of Cologne) gives us an idea of what the recorder was like at the end of the Middle Ages. The range of the instrument was probably an octave and one sixth, possibly a little more, with somewhat different fingerings from those of modern recorders. Its bore was probably cylindrical.
In this picture one of the musicians is playing with his right hand uppermost. This was current practice at the time, and could be done because the last hole was bored on both sides of the instrument, as can be seen on this fragment of a recorder probably made in the 14th century. The unused hole would have been filled with wax.
Click here for more information on the inverted hand position on the recorder.