Subject: Re: Disklabel(5)/(8) ??
To: Henry B. Hotz <henry.b.hotz@jpl.nasa.gov>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 10/07/1996 20:05:33
> "Native disklabels" are the native disk partition map used by NetBSD.  You
> would see them on either of the Sun ports I expect.

Playing the devil's advocate again, you'd also see sun disklabels,
which are different. :-)

> Using the Apple partition map also allows you to share a single disk among
> MacBSD, MacOS, and A/UX (and MkLinux for that matter).  Since these are the
> systems we are most likely to share disks with I actually like the current
> set-up.  It also means that the needed information is only stored in one
> place and therefore cannot inconsistent.
> 
> The down side of the current scheme is that it appears to complicate
> dealing with recalcitrant disks like the Zip and EZ135 (I don't have one
> myself).  I can see some value to being able to edit the information with
> the BSD tools to fix strange configurations.

Not really. I have a zip, and the problem with it is that it doesn't
support the command typically used to get the size and layout of
the disk (mode sense, I believe). Normally disklabel just asks an
SCSI drive how many tracks, sectors, heads, etc it has. Zips don't
answer nice. :-( But that's the top half of a disklabel; the partition
layout is a different part (which is gotten right on the Zip, except
that the drive size is gotten wrong, so real partitions are smaller than
partition c!).

> However I am not sure why any of this is relevant to the IWM driver effort.
> I want floppy support mainly so I can trade disks with Mac's and PC's.  Is
> there really a native BSD floppy format that requires a disklabel, that
> people actually use?  If I were using a floppy to trade data with another
> Unix machine I would probably use tar format, not a full formatted BSD
> filesystem.

As I understood it, the IWM only supported GCR, an Apple data format.
All other 3.5" floppies use NRZ (or some variant there-of), so the
data's not readable by anything else. I'd be happy to be corrected
on this one, though, as it'd mean that the IWM could write 720K DOS
floppies!

> I'm really glad someone is working on an IWM/floppy driver.  Really, I am!

As am I. :-)

Take care,

Bill