Here's the response from AC:
Lisa,
Your e-mail was forwarded on to me. The version of THE EMPIRE STRIKES BACK screening during our upcoming "Films of 1980 Series" is the digitally restored version re-released several years ago; this is the only one currently available for screening.

Best,

Dennis Bartok
Head of Programming,
AMERICAN CINEMATHEQUE

Ahhh, the films of 1980. It brings back many memories, I was a freshman. I remember seeing Elephant Man and Star Wars in the theater. I think we saw Blues Brothers at the drive in, it's a little fuzzy because we were drinking heavily.

It does make me feel old when I realize how long go that really was, ugh!