[rescue] scsi id arrangements on plextor ultraplex

Jonathan C. Patschke jp at celestrion.net
Sat Jul 22 04:07:53 CDT 2006

On Sat, 22 Jul 2006, Dimitar Vasilev wrote:

> I need to leave the first pair of jumpers free and tap the next two pairs to
> get scsi id6, which my machine wants.

According to the URL you posted, yes.  However, every drive I've seen
has the ID bits in the reverse order (4, 2, 1 instead of 1, 2, 4).  If
you have the jumpers set as you've described, and the computer sees the
drive at target 3, you need to move the jumper over the third set of
pins to the first set of pins, like this:

   Before:              After:
       -  -              -  -
    * |*||*|            |*||*| *
      | || |            | || |
    * |*||*|            |*||*| *
       -  -              -  -

You will also want to make sure that the "PRTY" jumper is in place; a
Sun expects that.

Lastly, you need to make sure the drive is in 512-byte block mode.  On
my Pioneer drive, that means having a jumper on the "BLOCK" pins.  I
would suspect the same is true of your Plextor, since PCs and
Macintoshes expect the drive to be in 2048-byte block mode..

After you have the jumpers in place, probe-scsi will tell you that the CD
drive is at target 6.

> I suppose it's something small, but as my experience with scsi is limited I
> can't say what I'm missing.

My guess would be that either the "PRTY" or "BLOCK" jumper is in the
wrong state.

> To note: I have not tapped the termination jumpers - i.e they are not
> terminated. Don't know if I should or not.

Leave the termination pins without a jumper.

Below is the URL of a photograph of my Pioneer SCSI DVD drive properly
configured for use on a Sun system.  The jumpers are in a different
order from your Plextor, but the settings should be the same on both.


(pardon the dust)

Jonathan Patschke    )   "A man who never dreams goes slowly mad."
Elgin, TX           (      --Thomas Dolby, "Valley of the Mind's Eye"

More information about the rescue mailing list