Tamron Adaptall 2 lenses for Nikon D40

Hello all adn g'day from Perth Oz

I just purchased a D40 recently and  I have a set of Adaptall 2 Tamron 
lenses that I would like to use with this camera. I used these on my old 
Pentax ME.

First question is:  Is this doable?

Second question:  Is there an adapter ring available for this match up?

I understand that the autofocus functionality will be gone.

Thanks for any input.

Joe from Perth Australia