Re: D9060 with OpenCBM (was: Mac Installation with Brew)

From: Ethan Dicks <ethan.dicks_at_gmail.com>
Date: Thu, 17 Aug 2017 23:02:30 -0400
Message-ID: <CAALmimkaA7in+=dtUMkwYQ95JESq-hme1DZ9igQqa1w2ksCSpA@mail.gmail.com>
On Thu, Aug 17, 2017 at 10:55 PM, william degnan <billdegnan@gmail.com> wrote:
> Bruce Faierson, the 2nd president of CBUG and owner of Northwest Music near
> Chicago (CBM dealership) sent me this email about 10 years ago, if helpful.

Interesting stuff.  Thanks for passing that on.

> He has since passed away unfortunately.  I am sure he'd be glad to know
> people are still working on these drives and interested in them.

Sorry to hear that, but I would think he'd be glad to know.

> The D9090 and D9060 are mostly the same

They are entirely the same except which physical drive is installed
(Tandon TM602S with 4 heads vs TM603S with 6 heads) and the position
of one jumper.  The firmware on the DOS board reads the jumper and
uses that for all the head calculations.

> http://www.vintagecomputer.net/commodore/IEEE_drives/D9090_testing.txt

On the formatting - there are a couple versions of the ROMs.  The
low-level format is done differently (I do not know the details) but
there is a substantial difference in formatting time, like 45 minutes
vs 2.5 hrs.  You just have to do a HEADER and walk away for a while
and come back and look for blinking lights.

It's _usually_ the drive mech that's bad if a format fails.  Those are
old drives.  They are also uncommon models.  Fortunately, one can sub
a Seagate ST225 in a D9060 or a Seagate ST241 in a D9090 and they work
(at the original 5MB or 7.5MB capacities at 4/6 heads and 153 tracks -
the extra tracks are ignored - it's probably possible to bump the
number of tracks up to 254 by altering the ROM code, but I don't
recall if anyone has done that).

-ethan

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Received on 2017-08-18 04:00:01

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