Are you talking about an Avid Mojo on that firewire port or just a camera or deck for digitizing?
A camera or deck will do just fine.
As for a Mojo, depends on the laptop and card. A cheap firewire card in the slot will not work. Too slow. Also, either way you can definately NOT digitize via Mojo to the external USB drives, only internal drive. Check out Avid’s qualified laptops and their specs on the avid site and get something similar.