Internal / external disks

[tttermite]

Hi there -

I'm trying to figure out how OS X designates drives as internal or external, and set this flag myself. I have permanently attached storage that I want to show as internal rather than external.

I think this has to do with whether the drives are considered 'hot swappable' or ejectable, but I'm not sure. I've seen this come up for users of hacintoshes, but I'm using a regular build of Mac.

Thanks!