Some disk formatters create a special disk partition or leave 
information on the disk for protection purposes that make it difficult 
to reformat the disk.  I can imagine that in a classroom this would be a 
neat trick to keep the students from blowing away the System.

While working on Mkfs some time ago I accidently wiped out the Apple 
Disk Partition Map.  Based on that experience I'm guessing that if you 
somehow managed to do that you'd be able to re-format the volume - if 
you had a floppy or CD boot volume to run from.  I haven't tried this 
but you should be able to delete the Apple Disk Partition Map and even 
install a new one using the "pdisk" utility.  There is a copy that will 
run on the 68k Mac on the NetBSD FTP site.  Just look in the 
arch/mac68k/misc directory.

BTW, if anyone tries this and it works it might be nice to include the 
hint in the FAQ.

Hope this helps,
-bob

On Monday, May 6, 2002, at 09:56 AM, Randy Grafton wrote:

> I got my hands on a Quadra 800. The system came with a 500MB hard drive 
> that
> has a sticker on it displaying the Apple logo and 'EPROM 1992'. The 
> company
> that I bought the system from wiped the drive clean before selling it 
> to me.
> When I try to use the Apple HD SC utility to partition the drive I get a
> message that says the process was unable to unmount the drive because a 
> file
> may be in use. This same message comes up when I try to initialize the 
> drive
> or remove the existing Mac partition. The drive is completely empty and 
> I am
> running the HD SC utility from a boot cd. When I look at the properties 
> for
> the hard drive it shows that a FWB driver is loaded. If I proceed with a
> straight forward Mac OS install everything goes fine. Any ideas how I 
> can
> reclaim this drive so that I can move forward with a NetBSD install?