Andrew and others...
This problem has already been discussed here at some length. The BIOS
on older PCs does not support larger disks and so trickery has to be
invoked in DOS to overcome this by using 3rd party disk tranlation
utilities - ONTRACK is the one I have had most experience of.
Linux can not see these disks if this trickery is used. I have just
changed to an EIDE controller (its made by adaptec and cost me 40
quid) which has its own BIOS support for larger disks , 2 IDE
channels so support for 4 disks/CD roms etc AND its faster. PLUS my
linux on a 2nd hard drive (233Mb) can now see the first disk (850Mb).
This was one of the reasons I changed the IDE card....
Hope this helps