Abstract: Supply and take-up reels are mounted above a horizontal base for selective powered rotation about respective vertical axes. Vertical guide surfaces and a cover panel define an air tight continuous flowpath extending between the peripheries of the reels past a read/write head. A blower mounted in a hood structure beneath the base sucks air through the flowpath and through a perforated center spool of the take-up reel. A river of air thus pulls and guides the free end portion of the magnetic tape from the supply reel to the take-up reel as the supply reel is rotated by a drive motor to unwind the tape therefrom. The supply hub is adapted to automatically center the supply reel thereon. The supply hub further includes a plurality of annularly spaced reel engaging pawls mounted in, and normally retracted into the hub, and an over-center actuating means for selectively extending the pawls through differential rotation of a pair of separate rotors included in the hub.