Intel's LGA 775 socket: Why no pins master?@ 2004/08/04
THIS BRINGS us to the million dollar question, why the change from pins to no pins. The answer is both simple and complicated. The simple bit is that the contacts you see in the LGA775 sockets have always been there in the older sockets, just in a slightly different form. The reason you never noticed them before is there was this perforated black plastic cover over them. That cover is now gone, and you can see the little metal bits that were previously hidden.