Sorry for the blast but we're trying to set up for a conference and can't get the iMac to interface to the hdmi input on 60" LCD. I've read quite a bit about the mini-DVI cable to hdmi cable adapter you need. We've purchased a hdmi cable and also the mini-DVI to hdmi cable. However, where do you plug it into the iMac? The only connections I see are the USB ports and the firewire port?