James wrote:

I don't know if the RR
board handles things differently at the drive level but since W98 saw
the full 600G in the beginning I think it should be very similar.

That's easy to see. Goto Device Manager - (your IDE controller) Properties
- Driver - Driver File Details. When ESDI_506.PDR is used AND this file
is Microsoft's, Windows sees this as a 'normal' disk.
This should not be the case, because then you can address only 128 GiB.