DD disks and HD drives (was: Where can I find...)

From: allisonp <allisonp_at_world.std.com>
Date: Sun Jun 25 10:20:55 2000

From: Douglas Quebbeman <dhquebbeman_at_theestopinalgroup.com>
To: 'classiccmp_at_classiccmp.org' <classiccmp_at_classiccmp.org>
Date: Sunday, June 25, 2000 9:56 AM
Subject: RE: DD disks and HD drives (was: Where can I find...)


>> I do it all the time, no problem. Key thing is while the drives
>> are HD capable (TEAC FD55GFV) I happen to have them
>> jumpered as required to properly run DD mode. In this
>> mode they are plain DD, DS 96 TP! drives.


                                          ^^^^^^^^^^ I repeat for the
impaired 96 TPI.
>
>Does setting that jumper cause them to write double-tracks,


NO.

>then (as ISTR that the HD drives wrote tracks that were
>half-width, and someone used to sell a software package


Yes, thats the ppoint of using 96TPI drives... to get more tracks.

>that wrote an HD-width track, stepped the head, then
>wrote an adjacent HD-width track to create pseudo-DD
>tracks)?

You can but, the reliability of the read data sucks to be blunt.
I said that you ccan do this in an earlier post if you needed
some special project hack to get you by. I don't as a good 48tpi
drive does a far better job and swapping it is no big deal.

I used 5.25 96tpi two sided double density for one reason easy to get
and use storage space. That mode does 720 or 782k depening on
the formatting were an older 48tpi drive will do 360k. Where 1.2mb
used funky media, data rates and all that are not easily found on
NON-PC systems.

Back in the old days using DD on a 96tpi drive was called QD.

>Hey, precisely what jumper is that?


I ave five different versions of the FD55-GF drives and they are all
different. So I did a lot of guessing and tried them until it worked.
A manual would have helped. I also ahve a few FD55Fs (also
96tpi DD two sided without ability to do the oddball 1.2mb format).

Allison
Received on Sun Jun 25 2000 - 10:20:55 BST