external firewire drive not recognized

[Robert Nuzum]

I have a 120 gig external firewire drive which boots osx easily but 
when I try to install YDL 4.0.1 the drive is not recognized. I thought 
this would be an easy install, as easy as ox, but I can find no 
information that resolves this. I tried to follow a note from the YD 
site that describes how to mount an external firewire drive but this 
fails. It suggests mkdir for mounting but I cannot find the drive or 
partition designations. The drive is partitioned via disk utility with 
free space in the first segment.
Thanks for any help,
Bob