Subject: Disk Geometry
To: None <port-i386@NetBSD.ORG>
From: Jeffrey Russell Horner <>
List: port-i386
Date: 07/19/1995 11:40:25
Okay, Why does this work?

machine: Elite P-90, WDCA31200... ( ide 1.223 gig), 16 ram, intel mb, amibios.

The BIOS reads the true geometry to be  c=2484 h=16 s=63, and fdisk reads the
true geometry as well. When I use pfdisk, I _have_ to specify the correct
geometry. I repartition as follows:

Part   ID     First     Last    Name    # i forget the rest
1      6        0        599     DOSbi  #   ?, ?
2      165      600      2483    NetBSD #   ?, ?
3      0        0        0              
4      0        0        0  

(of course the above is a generic interpretation)

I reformat the disk, reinstall DOS on the first partition, make sure fdisk
still contains the partition table entries I specified in pfdisk.

Then I boot the NetBSD1.0 kernel image and insert the install disk.
I give it c=601 as the netbsd partition offset and c=1883 for the partition
size. REBOOT works great, netbsd comes rigt up :-)

IF i give the offset as c=600, and try to reboot, it goes right into ms-dos
because the first partition is marked active. When I mark the second partition
as active, reboot, I get "Missing Operating System". Why? 

I've read thru the mail archives and still haven't created a clear picture of 
what is going on with what NetBSD1.0 is doing to the partition table. Can 
someone explain this phenomenon?

Jeffrey Horner