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35mm lenses are compatible with digital SLRs, but the opposite isn't true. Since digital SLRs have sensors that are smaller than a 35mm film frame, they don't get the same angle-of-view from lenses designed for 35mm film cameras. In order to have real wide-angle lenses for digital SLRs, manufacturers have begun making wider lenses with smaller image circles. A smaller "image circle" means that the area the lens focuses on is smaller. So digital specific lenses won't cover a whole 35mm film frame. If you use a digital lens with 35mm film you'll end up with a black circle around the outside of a small image.
So, the kit lens will not work with the N80. But long lenses and regular 35mm film lenses will work fine on the D70. just remember that any lens you use on the D70 will have an adjusted, effective focal length about 1.5x longer than the number on the lens.
I hope I explained that adequately. Let us know if you have more questions.