Thanks guys, I wish I could find a 'classic' one with more than a split second to see it though, lol.
I've been on a search for the version the way it seems to be most often taught these days. Here is a good one...pretty much. The thing about this is there is nothing "wrong" with it as long as it is sound and healthy. Here the guy is flexing at the knees as he goes down and then extending them on the way up but not ever straightening them completely.
In watching this a couple times some things I don't like is the way he is looking up. He really should have his chin tucked a bit. I know people are taught to do this as well...look up. Bad mojo. To tell the truth his arch is probably excessive. You want a slight natural arch not an exaggerated on. I kind of wonder whether the head up posture promotes that kind of thing. In both vids they are sort of looking up. Not real exciessive but I use my eyes not my head to look forward. If you try to tuck you chin while looking up I find that it cancels out the tendency to extend the neck and helps produce a neutral neck.