Downloading HDV/DV footage from Sony HVR-25U

I have lots of old HDV/DV tapes and need to download them to my Mac to edit in Premiere Pro. I bought a very decent used Sony HVR-25U deck, which takes both formats. The deck runs tapes nicely, however, it has a 4-pin firewire port, so I bought a combo IEEE 1394 4-pin to 9-pin firewire cable to connect to my desktop, but the computer doesn't see the deck. Or at least I can't find it. Does anyone know if there's some trick to this?