Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!uakari.primate.wisc.edu!xanth!cs.odu.edu!src
From: src@cs.odu.edu (Scott R. Chilcote)
Newsgroups: comp.sys.atari.st
Subject: Re: Single-sided atari drives
Summary: It can be done
Message-ID: <11905@xanth.cs.odu.edu>
Date: 22 Mar 90 20:51:22 GMT
Sender: news@cs.odu.edu
Reply-To: src@cs.odu.edu (Scott R. Chilcote)
Distribution: na
Organization: Old Dominion University, Norfolk, VA
Lines: 47


In article <633@ksr.UUCP> fay@ksr.UUCP (Peter Fay) writes:
>Has anyone tried upgrading one of those old cruddy single-sided Atari
>external drives to a double-sided drive by just pulling out the old
>drive and inserting a 720K TEAC or whatever?
>
>-pete fay

I have a drive much like the one you describe sitting in front of me here.
It works pretty much the way you describe, but there are a few things you
have to look out for.
 
The worst problem involved is the fact that SOME DSDD 3.5" mechanisms won't
work with the Atari drive controller setup.  If you get one one of these,
which include some Chinon, Toshiba, and a few other brands of drives, it
won't know when you've changed disks.  Having a drive that doesn't know you've
swapped disks is disasterous.  It won't read the new directory, and it will
overwrite data on your replaced disk.  I know someone who had a drive like 
this and he was out $40 for the thing... Granted, a small loss.
 
I'm using a TEAC mechanism, and it works fine.
 
The second worst problem when making this upgrade is that not all Atari
single-sided drives are built the same.  Some of them are quite unusual.  A
friend of mine has a SF-354 which uses an oddball mechanism that requires
the Atari PCB inside to have a fairly large amount of logic on it -- lots
of chips including a controller.  If you have any LSI chips on the PCB in
your SF-354, I doubt that a drive mechanism swap will work.  It's expecting
a different type of bare drive than the 'standard' PC type.
 
Other considerations: Fit.  My Teac drive is significantly smaller than the
one that used to be in there.  It also couldn't use the faceplate that was
on the drive.  I wound up carving out most of the front of the case and using
a carved 5 1/4" adapter plate from a PC for the opening.  I had to use a
cunning array of brackets inside the case to support this tiny thing, since
it wouldn't fit on the old mounting holes.
 
The only other thing I had to do was extend the power supply plug; the wires
were too short to reach once the thing was in position.  This took some
splicing and soldering but went okay.
 
It took some work, but I had it up and running in half a day.  The Teac cost
me $55 at a computer show.  It was definitely worth it!
 
------------------
src@cs.odu.edu
Scott Chilcote