<:: Perhaps this will help others out there in dating KIMs.... I tried <::slicing into the card to count the rings, but the results were <::inconclusive. < <I can definitely say, without even getting mine out of the closet, that I <probably have one of the youngest. Mine is a Revision D KIM-1, and it's <a Commodore board, not a MOS Technology one. The one I have is a 1977 (date codes on chips) with REV-B etch and the only number on it is a crude 5404 white stamp on the back. It works! Allison