[Coco] Issues with NitrOS9 build

Christopher R. Hawks chawks at dls.net
Sat Jan 25 09:40:34 EST 2014


On Sat, 25 Jan 2014 16:08:01 +1000
"Bob Devries" <devries.bob at gmail.com> wrote:

> Well, I got it to work, but I fail to understand why.
> 
> I changed offset $10 (DD.FMT) in LSN 0 from $07 to $03, and it boots
> correctly.
> 
> That change makes the disk a 48TPI instead of 96TPI.

Bob:

	If IT.TYP is 1 (or bit zero set), it is a 3.5 inch drive and
DD.FMT bit 2 clear means 135 TPI not 48. (It sez in rbf.d)
 
> Why does the TPI setting have *any* effect on the operation
> especially in an emulator. *something's* not right here.

	Dunno. I do know that my REAL 720k 3.5 inch drive only works
with NitrOS9 with IT.TYP = 1 and DD.FMT = 3. (Don't have a 5.25 720k
drive.)

> Regards, Bob Devries
> Dalby, QLD, Australia
> 
> ----- Original Message ----- From: "Bill Pierce"
> <ooogalapasooo at aol.com> To: <coco at maltedmedia.com>
> Sent: Saturday, January 25, 2014 2:55 PM
> Subject: Re: [Coco] Issues with NitrOS9 build
> 
> 
> >
> > Bob,
> > Could it be that Vcc drive emulation is not recognizing the 80trk >
> > properly? After all, it is a 35trk SSDD emulation when in
> > rsdos/rgbdos. > Personally, I've never had any luck booting 80trk
> > disks in Vcc, but the > repo has never had disks this good
> > either :-)
> >
> >
> > Bill Pierce
> > "Today is a good day... I woke up" - Ritchie Havens
> >
> >
> > My Music from the Tandy/Radio Shack Color Computer 2 & 3
> > https://sites.google.com/site/dabarnstudio/
> > Co-Webmaster of The TRS-80 Color Computer Archive
> > http://www.colorcomputerarchive.com/
> > Co-Contributor, Co-Editor for CocoPedia
> > http://www.cocopedia.com/wiki/index.php/Main_Page
> > E-Mail: ooogalapasooo at aol.com
> >
> >
> >
> >
> > -----Original Message-----
> > From: Bob Devries <devries.bob at gmail.com>
> > To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> > Sent: Fri, Jan 24, 2014 11:43 pm
> > Subject: Re: [Coco] Issues with NitrOS9 build
> >
> >
> > I did a CMP of the os9boot files on the 40 track disk
> > (nos96309l2v030209coco3_40d_1.dsk) and the os9boot file on the 80
> > track > disk (nos96309l2v030209coco3_80d.dsk) and found that the
> > only differences were two bytes in each Dx module (IT.TYP and
> > IT.CYL) and of course, the CRC > bytes for each of those (4)
> > modules.
> >
> > So why the failure of the 80 track image?
> >
> > Regards, Bob Devries
> > Dalby, QLD, Australia
> >
> >
> >
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco 
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco




Christopher R. Hawks
HAWKSoft
-- 
Two things fill my mind with ever-increasing wonder and awe: the starry 
skies above me and the moral law within me.		--Immanuel
Kant



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