Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!rice!uw-beaver!cornell!johnhlee
From: johnhlee@svax.cs.cornell.edu (Johnny H. Lee)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: PC 720k drives on Amiga HELP?
Message-ID: <45741@cornell.UUCP>
Date: 12 Sep 90 23:48:13 GMT
References: <4302@crash.cts.com>
Sender: nobody@cornell.UUCP
Reply-To: johnhlee@cs.cornell.edu (Johnny H. Lee)
Organization: Cornell Univ. CS Dept, Ithaca NY
Lines: 46

In article <4302@crash.cts.com> oleg@crash.cts.com (Oleg Rovner) writes:
[...]
>My external drive (an original 1010 from 1985) just ate it, or more properly
>the drive mechanism did. Now, I was wondering if I could take a 720k IBM 
>drive mechanism that I have laying around and plug it in. So I did. It 
>doesn't work. The mechanism is plugged in place of the old drive mechanism
>(ie the 1010 case/ic board) and I get two? problems, 1. No formatting (the
>drive DF1: is BAD on bootup, formatting doesn't work, aborts with the
>no sector header error on track 0) 2. Media change detection doesn't work.
>
>The drive model is Toshiba ND-3521GR, if someone could point me toward a 
>solution, or better yet, provvide one, I'll be eternally grateful.
>
>Regards,
> OR

I've successfully interfaced three Toshiba drive to Amigas (one for my
brother, my uncle, and myself) and they work great (one going on six
months with no problems.)  However Toshiba makes several different models
with different abilities.  Mine were series ND352, FDD4216.  These are
720K drives with a diskchange and jumper-selectable RDY/diskchange signal.
The interface boards I built basically latches the MOTORON signal which
the Toshibas won't do.  (Could be the cause of your problem #1.  Plenty
of schematics to do this are floating around.)

You didn't give the FDD number (assuming you even have one.)  Some of the
other drives in this series with different FDD numbers (like 4202, 4206)
won't work (no diskchange) but the FDD4210 will.  I picked up the 4216's
for $10 a piece at the ACP swapmeet in Orange County, CA from Jade Computers
who were dumping some untested surplus pulls.  I figured that I could
piece together a working drive from the parts.  But when I plugged them
into my drive 1 spot in my 2000, surprise!, they all worked fine.  Lucky
I guess.

If your drives don't generate the diskchange, you can:
	1.  Use the DISKCHANGE command.  Not very appealing, but it works.
	2.  See if the drive actually has the circuitry, but is simply
	    not enabled, perhaps because of a jumper.
	3.  Somehow wire-in your own switch and circuit to do it.  This
	    can be a bit tricky, but its not impossible.

Good luck!
-------------------------------------------------------------------------------
The crew goes in search of Leo!  Next time on AmigaDos: The Next Generation.
	John Lee		Internet: johnhlee@cs.cornell.edu
The above opinions of those of the user, and not of this machine.