Hard disk drive (HDD) sizing questions - 48-bit LBA enhancement to the ATA interface

[' =JeffH ']

Ok, I want/need to figure out how big a HDD I can upgrade internally to on my 
Dell D820 lapstation.

How does one go about figuring out whether there are any hard and fast 
restrictions given the internal IDE/ATA disk interface and/or BIOS 
implementation peculiarities?

I've been told that the limit on this machine is nominally a 120GB disk (on 
the internal ATA/EIDE disk controller interface). But that might be someone 
with a Windows focus. I'm running (k)ubuntu 6.10 Edgy.

Some modest research indicates that this system (e.g. the BIOS) might be 
subject to the "48-bit LBA" problem/issue, but also that it's possible that 
the Linux 2.6.* kernel might obviate any issues and I'm all set.

Without yet buying a > 120GB disk and trying it, how do i figure this out?

thanks,

=JeffH