Originally posted by mach23andy:
Trying to boot os x.3.5 from an external firewire enclosure with a western digital 30 gig drive inside and can't get it to work. I've tried having the pins in diff. configurations on the back of the hd and no luck. After the install I noticed the screen went white and was just sitting there and so I figured it was trying to boot from the ext. and it was like that for a long time. Anyone have any idea what is happenin'?? 
Andy
I have my firewire hd jumpered as master. That was the factory setting.
At startup you can hold the option key (alt). Then you will see the mac bootmanager. Your internal hd and the firewire hd should appear there if and only if there is a bootable system on the drive..
If the firewire hd does not appear, think again if its really bootable. How did you get a working system on the drive?
I recommend to copy your internal hd with carbon copy cloner. This should work and make the system bootable.