Path: utzoo!attcan!uunet!elroy.jpl.nasa.gov!sdd.hp.com!uakari.primate.wisc.edu!caen!sol.ctr.columbia.edu!ira.uka.de!fauern!NewsServ!rommel
From: rommel@Informatik.TU-Muenchen.DE (Kai-Uwe Rommel)
Newsgroups: comp.os.minix
Subject: Re: IDE disks
Keywords: minix, at, install, IDE, MFM, RLL, SCSI, ESDI
Message-ID: <1991Mar1.191845.18634@Informatik.TU-Muenchen.DE>
Date: 1 Mar 91 19:18:45 GMT
Sender: news@Informatik.TU-Muenchen.DE
Organization: Technische Universitaet Muenchen, Germany
Lines: 27

I have a Seagate (SWIFT) IDE drive (ST-1239A) with ~205MB. To use such a
drive with DOS, for example, you have to cut it below 1024 cylinders
which requires you to translate to more than 17 sectors per track.
Seagate recommends 36 sectors/14 heads/818 cylinders. Because I want to
use that drive with Minix in the near future (I'm not yet ready to try
it out), I have a more general question:

Will the standard AT harddisk driver of Minix recognize such disks with
more than 17 sectors per track and handle them correctly?

I think, that's the point. The IDE drives which I know are all WD
register compatible and at least the drive/host adaptor combinations I
have tested do not have any BIOSes on them and thus I assume the
translation is done in hardware.

That some of these disks do not work with Spinrite, may be caused by the
fact that IT IS NOT RECOMMENDED TO LOWLEWEL FORMAT ANY IDE DRIVE,
because that destroys bad-tracking info on the drive. My drive for
example, does not show ANY bad tracks, probably because it has some
spare tracks which are remapped to bad sectors (when doing a sequential
read verify test, one can feel it seek sometime over a longer part of
the disk instead of only doing track-track-seeks). This remapping is
probably destroyed by lowlevel formatting it. Some drive thus may have
some lock to prevent it from beeing lowlevel formatted.


Kai Uwe Rommel