RE: CBM 8280

From: Andrew Vardy (
Date: 1999-09-11 22:19:14

Date sent:      	Mon, 6 Sep 1999 20:19:00 -0600 (MDT)
From:           	Steve Judd <>
Subject:        	RE: CBM 8280
Send reply to:

> Hi Bill,
> On Fri, 3 Sep 1999, William Levak wrote:
> > HD disks use a magnetic particle that requires a higher electic field to
> > write them.  In addition, the write head is narrower.  If you use a SD,
> > DD, or QD disk in a HD drive, the higher electric field will cause the
> > signal to be spread over adjacent tracks.  If you format a DD disk to a
> > DD capacity in a HD drive, then you will be able to read and write it
> > because of the greater spacing between tracks.  You will, however, only
> > be able to use it in a HD drive because the main signal is too narraw to
> > be read reliably by a DD drive.
> This seems backwards to me, and runs counter to my experience.  I would
> think that the lower current of a DD head would mean that sometimes the HD
> head has a problem reading it.
> I use my Amiga (DD) to transfer files to my FD2000 (HD) drive, using
> Pasi's c1581.  It is never a problem reading files that the FD has
> written.  I do, however, sometimes have problems reading files on the FD
> that the DD Amiga has written -- the files are perfectly readable on the
> Amiga, but generate a read error on the FD.  And once the read error
> exists, only reformatting the disk will make it go away.

Actually, I wrote a program to fix read CRC read errors on FD2000 
disks FYI.  Don't know what kind of errors you've had.

> Anyways, I've never had problems reading DD files/disks created on
> the HD drive, but I've had numerous problems going the other way.
> > for secret information.  Military security protocols specify that a disk
> > containing secret information must be overwriten a certain number of
> > times with random data in order to obliterate the residual signal.  Or,
> > you can bulk erase it.
> Or burn it.

How fast can you burn a disk?  (LOL)

Seriously though, for fun.  What do you think?  Dunno what those 
things are made of.

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