Abstract: This invention provides improvements in nail feeding control as presented in U.S. Pat. No. 3,273,776. The ratchet system of the reference patent has been improved upon by use of a two-position drum bar which is moved by a cylinder. The latter is activated by a programmer to select nails in accordance with a first predetermined pattern for the top deck of, for example, a pallet, and at the other position a second predetermined pattern of nails is fed for driving into the bottom deck. Any number of stringers may be attached using the one pattern for the top deck and the other pattern for the bottom deck.