CF > 1Gb on MP780?

Ive been running NetBSD 1.6 (yes, old!) off a 256Mb CF card
on my MP780 (a 
little cramped - no X and no man pages).

Anyway, in order to upgrade to 3.x (and to treat myself to a
bigger 
install) I bought a shiny new 1Gb CF card. My problem is
that sysinst 
tells me it sees 1000M but the BIOS reports 500M. Is there
any way I can 
persuade sysinst to use the whole disk? Ideally, Id keep 4Mb
as FAT for 
hpcboot.exe and devote the rest to NetBSD.


-- 
Aj. (ajaibitblit.net)