Latitude motherboard, unused socket, what might it be for?

Archived from groups: alt.sys.pc-clone.dell (More info?)

Hi,

I have just upgraded my Latitude CPx from a 450MHz CPxH motherboard to a
750MHz CPxJ.
That was fine and it all works well.

On the new motherboard I noticed a small socket near where the sound ports
are, which looks like it's labelled 'JMDM'. Any idea what this socket is
for?

One thought was that it might be a for an internal modem, but I'm not sure
where the phone cable would plug in if it was. The older m/b had a place for
the socket but no actual socket.

Regards, John