How do I get a copy of my certificate/diploma from control data institute Atlanta ga 1979? State only has transcripts no certificates or diplomas.

If they are closed, there is no way to get a diploma or other certificate. And honestly you do not "need" it, they are really no legal proof, they are just something you hang on your wall. If you want to hang one on the wall, make one or have a printing company make one that looks a lot like the ones issued.

The transcript is the actual legal proof that you attended and graduated.