Path: utzoo!attcan!uunet!snorkelwacker!apple!mips!prls!pyramid!athertn!alex
From: alex@athertn.Atherton.COM (Alex Leavens)
Newsgroups: comp.sys.atari.st
Subject: Re: HELP!
Summary: Problems with a hard drive...
Message-ID: <19921@laurel.athertn.Atherton.COM>
Date: 14 Mar 90 16:50:23 GMT
References: <2193@husc6.harvard.edu> <2199@husc6.harvard.edu> <2207@husc6.harvard.edu>
Reply-To: alex@Atherton.COM (Alex Leavens)
Organization: Atherton Technology, Sunnyvale, CA
Lines: 46

Ken Clubok
clubok@husc4.harvard.edu writes about problmes he's having with his hard
drive, to wit, lots of bad sectors, problems reading from the disc, etc.

One thing to check, if you've assembled the drive yourself, is to see if
the Adaptec controller card is sitting too close to the drive's own 
controller electronics.  I had a variation of your problem which went like
this:

Everything opened up and laid on the table--drive, controller, BMS board;
in this configuration, everything was seperated, and the drive would format
and read/write just fine.

Everything boxed up in the case, Adaptec board mounted to bottom of drive,
next to drive electronics:  Can't format drive, too many bad sectors.
(So how come they put mounting holes for a controller on the bottom of the
drive then???)

Cobble up a mounting bracket, move Adaptec to top of drive.  Now the drive
controller cable (34 pin) and drive data cable (20 pin) are coming up the
back of the drive and over onto the Adaptec;  they are no longer running
next to the drive electronics.  Result: Can format drive, and use it, but
get intermittent read/write errors, (often filenames 'change' with one
or two characters becoming garbage).

Ok, now I'm getting pissed.  Get out the aluminum foil and the soldering
iron.  Make a sandwich of cardboard and aluminum foil (carboard outside)
and put one between adaptec and drive.  Do the same thing for the back of
the drive, so that the drive control and data cables are outside of the
sandwich, and the back of the drive is on the inside.  Do the same
for the bottom of the drive.  Enclose my SCSI<->ASCI board in another
couple of these sandwiches.  Run ground wires from the aluminum to the
ground on the various boards.

Everything works fine now.  Shees!

Moral:  You may need shielding, lots of it.

Hope this helps!



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