[rescue] imaging old Mac double density floppy disks

Geoffrey S. Mendelson gsm at mendelson.com
Mon Jun 19 14:35:11 CDT 2006

On Mon, Jun 19, 2006 at 03:24:24PM -0400, kevin wrote:
> Someone told me that the old Macintosh DD floppy drives (not the 
> SuperDrives of days past) were "special" and that it was not 
> possible to read older Mac formatted DD floppies using a PC 
> floppy drive.  Anyone know if there is any validity to this?  I 
> thought that none of that would be relevant if i was using dd 
> (i'm not mounting the disks, just trying to image them).

They are correct. The bit encoding is completely different, and the
drive uses a variable speed motor to keep the sector sizes the same.

It's not that the data is formated differently, the data is ENCODED

> Any ideas?

Buy a Mac with a 680x0 processor and ethernet. Use MacOS 7 or 7.5
(both downloadable) and Apple's Diskcopy (also downloadable) to make the
images. Then you can archive 400k (single sided) and 800k (double sided)


Geoffrey S. Mendelson, Jerusalem, Israel gsm at mendelson.com  N3OWJ/4X1GM
IL Voice: (07)-7424-1667  IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
Visit my 'blog at http://geoffstechno.livejournal.com/

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