[Coco] OS-9/68K raw disk access syntax

[David Ladd]

Gene,

​​
The MM/1 and the OS-9/68K uses 512byte sectors for its disk format.  The
biggest oddity with the more current OS-9 is that it uses a starting sector
#0 rather than #1 on each track.  The biggest thing is having a utility
that knows this and is able to start with reading at sector #0.
​​

On Fri, Jan 1, 2016 at 10:02 PM, Gene Heskett <gheskett at wdtv.com> wrote:

> On Friday 01 January 2016 22:39:53 Joel Ewy wrote:
>
> > On 01/01/2016 07:34 PM, David Ladd wrote:
> > > ​​
> > > I might be wrong, but if memory serves me I think the MM/1's
> > > OS-9/68K formatted floppies sectors per track starts at 0 rather
> > > than 1 like some of the older floppy formats use to be.  So may have
> > > to take that into account.  Sadly I can't verify this at this time
> > > as my MM/1 is currently packed away.
> > >
> > > ...
> >
> > You're right about that, as I've discovered.  I think that's causing
> > me a problem when trying to image the disks with 'dd' under LInux on a
> > PC.
> >
> > JCE
>
> Sadly, there are fdc chipsets built into some good motherboards that any
> attempt to read or write a coco's 256 byte sector will take the machine
> down, with the only recourse being the hardware reset button and a full
> reboot done.
>
> This machine, with a nearly $300 when new Asus M2N-SLI Deluxe mother
> board in it, is one such machine.
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco
>