Subject: Re: Floppy driver
To: David Jones <>
From: Gregory Kritsch <>
List: amiga-dev
Date: 03/01/1994 12:24:16
> > Probably the best way to do this is to have the disklabel faker routine
> > report two partitions, a which skips track 0, and c which covers the
> > whole disk.  You'd use 'a' in conjunction with adosfs, and 'c' with tar,
> > msdosfs, ufs, and everything else.
> You mean block 0, right?  I don't want to skip a whole track!

Random thought based on SunOS:

Suns have three ``partitions'' on their floppies - a is track 0,
b is tracks 1-79, and c is the whole disk (a and b might be reversed).
I've never quite understood why, but...

The Amiga FFS reports the disktype as the first four bytes of sector 0
on the disk.  Workbench displays icons labelled DF0:KICK (for example)
where KICK is a copy of those four bytes.  DF0:BSD_ would certainly make
me think the disk is formatted.  So there's a use for the a/b mpartitions
(stick BSD_ in a and use b for tar or ufs).

Most of the time, I can remember not to randomly format disks tha aren't
AmigaDOS (maybe it's because I use raw floppies for tar and MS-DOS disks
on a regular basis).  If it becomes a problem, I can even stick a label on 
them saying ``NetBSD disk''.  This seems a much better solution to me than 
wasting a bunch of sectors on the disk.

However, if someone really wants to get fancy, have a magical d partition
which skips track 0 and track 40, or the relevant portions thereof.  Now,
except for the fact that we need some special code in fdformat to produce
a d-partitioned disk, I think everyone can be happy.

> David Jones, M.A.Sc student, Electronics Group (VLSI), University of Toronto
> email:, finger for more info/PGP public key