           SOFTERR v1.0 - detect soft disk errors
           --------------------------------------

SOFTERR version 1.0 is Freeware by Roger Burrows, Anodyne Software.
It is hereby placed in the public domain, and may be freely copied
and distributed.  Please keep the program executable and this
documentation together - thanks.



Description
-----------
SOFTERR is a program to determine if you are experiencing 'soft'
(also called temporary) read errors on your hard disk partition(s).
In this context, a 'soft' error is an error that is successfully
bypassed by the hard disk driver retrying the read.



Why do I care?
--------------
In many cases, 'soft' errors are an early sign that 'hard' (also
known as permanent) errors are developing.  If you see many soft
errors, or if you run this program over a period of time and see
the number of soft errors increasing, you may wish to consider
one or more of the following:
   . take more frequent backups :-)
   . backup the affected partition(s), overwrite it with a program
     that rewrites every sector, and then restore the partition(s)
   . replace the disk
Note that if there are a significant number of errors on _any_
partition on a disk, this may be a sign that the _whole_ disk
is becoming less reliable.

There are also cases where soft errors only occur when reading
many sectors at once; they do not occur on single-sector reads.
This can slow down access to data in the partition (due to retries)
even if it does not (yet) indicate impending disk failure.

This program assumes that your hard disk driver implements the
Atari AHDI 3.00 specification; most drivers do.  This allows the
program to prevent the driver from doing its own retries.  If the
driver does _not_ implement this feature, then anything reported as
a soft error is really a hard error, since retries have already
taken place.



What's reported?
----------------
For each partition tested, every logical sector is read, 192kb at a
time, with retry disabled.  If any error occurs, a multi-sector
soft read error is counted, and the failing group of sectors is
reread, one at a time.  If it is successfully read the first time,
no single-sector error is counted; otherwise it is reread a maximum
of 3 times.  If it is successfully reread before the retry count is
exhausted, it is counted as a single-sector soft error; if the read
still fails after 3 retries, it is counted as a hard error.

This mix of read sizes ensures that the program detects soft errors
that occur only when multiple sectors are read, but does not detect
a hard error unless a single-sector read fails at least 3 times in
succession.

While testing a partition, the number of the logical sector being
read is displayed; at the end of testing a partition, the following
statistics are displayed:
   the number of logical sectors in the partition
   the number of multi-sector reads
   the number of soft errors detected in multi-sector reads
   the number of logical sectors in the partition
   the number of logical sectors with soft errors
   the number of logical sectors with hard errors.



About Anodyne Software
----------------------
Anodyne Software develops and sells CD-related software for Atari
systems.  Our current products include CD Writer Plus and ExtenDOS
Gold.

CD Writer Plus, in conjunction with ExtenDOS Gold, allows you to
create audio and partition backup CDs on your Atari, using a standard
SCSI CD recorder (CD-R or CD-RW).

ExtenDOS Gold is an extension to Atari operating systems, including
TOS, MultiTOS, MagiC, and Geneva.  It supports a wide range of both
CD-ROM and CD-R drives on all Atari TOS-based systems, including the
ST, STe, TT030, Falcon030, and compatibles.

ExtenDOS Gold and CD Writer Plus are available from your Atari dealer,
or direct from Anodyne Software at the following address:

     Anodyne Software
     6 Cobbler Court
     Ottawa
     Ontario K1V 0B8
     CANADA.

If you have Internet access, visit our web site at:
     http://www.cyberus.ca/~anodyne
or contact us by email at:
     anodyne@cyberus.ca

Roger Burrows
26/January/1999
