Path: utzoo!mnetor!uunet!husc6!ukma!rutgers!mtune!lzaz!hcj
From: hcj@lzaz.ATT.COM (HC Johnson)
Newsgroups: comp.sys.atari.st
Subject: SH204 disk errors
Message-ID: <46@lzaz.ATT.COM>
Date: 4 Jan 88 21:09:53 GMT
Organization: AT&T ISL Middletown NJ USA
Lines: 24
Keywords: sh204, disk, strange behavior


There have been many posting with regard to strange ST behavior
when using the SH204 disk.
After discussing this with Chris at BMS I learned the following:
1. SH204 seems to report 8 drives per controller.  I saw this with
   the BMS driver on my SH204.  Also Magic -Sac describes this.
2. That isn't the problem.
3. SH204 CANNOT report ANY ERROR to the computer.

So why doesn't everyone die on a disk error?  The Adaptec interface
does the retries, and if successful, all is well.  What happens
if the sector is BAD? You read in junk, fail to get the error message,
and see strange things.

BTW, hdx CANNOT mark as bad the blocks in the root directory or the SAMS.
This creates really strange problems when a block changes, as when
adding files and suddenly 5 megabytes dissapper.

I solved my problems 2 ways.
1. I changed hdx to accept a list of bad blocks and let Adaptec remove
   them permanently.
2. I now use a BMS controller.  Highly recommended.

Any one want to buy a slightly used SH204?