All of Nikon's DSLR's with a built in AF motor allow you to use the sub command dial for aperture setting by locking the f stop to it's smallest aperture on D type lenses. The D600 also allows full range of the aperture ring. To use the aperture ring you need to set f5 in the custom settings. See page 245 in your manual.
I don't know if the D80 allows using the aperture ring also.