SUMMARY: Dumb SMD question

From: Ted Nolan SRI Ft Bragg (
Date: Tue Mar 24 1992 - 19:18:11 CST

Hello folks,

It you'll remember, I asked a couple of questions about SMD cabling and
the Sun 7053 controller a week or so ago. I got a lot of helpful responses,
some of which I'll include below, although as you'll see near the end,
the project as a whole never quite came off...

First, the original question:

Subject: Dumb SMD question
Date: Wed, 11 Mar 92 11:54:54 EST
From: Ted Nolan SRI Ft Bragg <>

Hello folks,

I've got 3 SMD questions today:

We've got a Seagate Sabre ST82500J 2.5 gig SMD drive we want to hook up to
a Sun 3/280. The machine currently has a Xylogics 7053 controller in it,
driving two NEC D2363 disks as xd0 and xd1. Our original plan was to have
a seperate controller for the new drive, but that currently looks a little

The 7053 has three sockets on the back. The bottom is labeled "Data
0,1", the middle one is labelled "CMD" and the top one is labeled "Data
2,3". We have the NECs plugged into the bottom and middle sockets. My
first question is how do we connect the new drive as xd3 when there is
only one CMD socket. It seems obvious we could use the empty "Data
2,3" socket, but how does one daisy chain to use only a single CMD

My second question is if we do scare up a second 7053, what switches do
I need to set on it for it to show up as xdc1 instead of xdc0?

My third question is about the drive itself. Assuming it is not formatted,
does anyone have a format.dat entry for it? Will we have any problems
putting a 2.5G drive on a SunOS 4.0.3 system? On a 4.1.1 system? (We are
currently 4.0.3, and want to upgrade to 4.1.1 concurrent with installing the
new drive. (And may want to preparition it off of a neighboring 4.0.3
system to save time).

Sid Shapiro ( was one of the many to contribue format.dat
entries, and explain the cabling:

Hi there,
I don't know about the controller switch settings.

For the disk, though, you daisy chain the CMD cable through the 2 necs
and then onto the sabre. Presumably there is a terminator on the
second nec, replace it with an "A" cable , plug the other end of the
A" cable into the sabre, then out the terminator on the other 50pin
outlet on the sabre. Easy.

As for compatibility with 4.1.1 and 4.0.3 - sorry again - I have one
of these puppies attached to a solbourne and Here is the format.dat
for it.

disk_type = "Sabre 97200-2500" \
        : ctlr = XD753 \
        : ncyl = 2609 : acyl = 2 : pcyl = 2611 : nhead = 19 : nsect = 83 \
        : rpm = 3600 : bpt = 50400 : bps = 600
partition = "Sabre 97200-2500" \
        : disk = "Sabre 97200-2500" : ctlr = XD753 \
        : a = 0, 18924 : b = 12, 66234 : c = 0, 4114393 : d = 54, 20501 \
        : g = 67, 4008734

Curt Freeland ( supplied actual controller settings:

> My second question is if we do scare up a second 7053, what switches do
> I need to set on it for it to show up as xdc1 instead of xdc0?

At jumper block JA you need to remove the jumper in position 4. For xdc0
it would be: (I == jumper installed)
4 5 6 7 8 9 A B C D E F
and for the xdc1 controller it would be:
4 5 6 7 8 9 A B C D E F
  I I I I
Bob Reardon(reardon@sws.SINet.SLB.COM) is one of several people who mentioned
potential firmware version problems in the controller:

Your questions are not dumb - the 7053 is not a straightforward device.
In regard to command chaining: The same signal is daisychained to all
disks (up to max of 4) and your cabling must handle that.
Whether you use your current 7053 or get a second one, *BE SURE* that
you have the right revision level. Here's the reason.
The older NEC disks have a relatively slow data rate ( I think it's
2.4 MB/sec, but could be wrong on the numbers). Because of that, they
can run on older 7053's with lower rev levels. If your new disks are
faster than the NEC's you may need a faster 7053. For example, we run
4 NEC drives on a 7053-105. A one time we wanted to install Fuji
drives (I forget model number). Because the Fujis were faster, they
required 5053-106 (or higher) rev controller. If your controller
is 7053-105 (or lower), be sure to ascertain that the new drives
are not too fast for it.
        Bob Reardon Reardon@HDS.Sinet.SLB.COM

Kevin Thomas ( also warned about
rev problems, and some drive settings:

I can't answer all of your questions, but I can help.

First of all, make sure disable sweep mode, otherwise you'll get complaints
from the SMD driver.

Second, I've been told that the Sun 7053 controller will NOT work with the
2.5gb drives. They aren't at the right rev. As to where you could get another
one, try asking the people who sold you the drive.

I'm running the SMD version on 4.1.2. I think I had it running under 4.0.3,
but that one is a while back.


Unfortunately, the final result of all this was that if I connected the
disk with default settings (which the manual says will let all the
disk's cylinders be used), I could only see the first 1024 cyls. If I
went to the setting where only the first 2048 cyls could be used, then
it worked beautifully, but leaving 561 cyls unused was not a Good
Thing. All this involved (immanent!) scheduled downtime, so I finally
put in a smaller drive we had intended for something else. After several
people mentioning controller revs, I suspected a firmware problem, which
Curt Freeland seconded in an off-list exchange:

Did the info I sent get you up and running?
Received: by (5.65/1.30jrs)
        id AA13265; Tue, 17 Mar 92 13:18:11 -0500
Date: Tue, 17 Mar 92 13:18:11 -0500
From: (Curt Freeland)
Message-Id: <>
Subject: Re: Dumb SMD question

        It (and the info from everyone else) surely helped, but unfortunately I ran
        into another problem, and had to drop back to plan B. I never could get
        the 7053 to see more than the first 2048 cylinders of the disk...
        I think it might be a firmware problem on the controller, but I'm not sure.
        I plan to summarize shortly, but I really appreciate your response.


                                        Ted Nolan

Yes, the firmware will do this to you. I think we have rev 2.3 firmware
in our units, and it works. Anything prior to that rev would not work. The
PROM part number should be something like 180-002-271 with a Rev of 2.3 or

So the final result is that we have a smaller disk online OK, and have
ordered a current controller for the next time we try to install the
NEC. Thanks also to Russ Poffenberger Rob Scott Ed Arnold and Benjamin
Cline, once again the speed and helpfullness of the folks on this list
is amazing.

                                Ted Nolan

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