Re: Help with SBB in BA353

From: Jeff Campbell (n8wxs_at_arrl.net)
Date: 08/09/04 

Date: 8 Aug 2004 20:32:23 -0700

"Thorsten Hahn" <Hahn0man@t-online.de> wrote in message news:<cf6a90$vr6$03$1@news.t-online.com>...
> Hi,
>
> I have a DEC "StorageWorks BA353 Desktop Expansion Unit" and a DS-RZ1DB-VW
> 9,1 GB SBB. HDD has power and starts, but I cannot see her at my VaxStation.
> Trying the disk internal with SCA-Adapter everything is fine.
>
> Printed on the SBB: For use with 300 Series Shelf or other devices as
> specified in manual (I donīt have the manual). Is the SBB broken or wonīt it
> run in this enclosure?
>
> The BA353 is o.k., SCSI-ID etc is checked also.
>
> Greetings from Germany
> Thorsten

The SCSI bus in a BA353 is narrow, that is the data path is 8 bits. As such
it does not have the other 8 bits necssary to support wide 16 bit SCSI data. The
problem you are seeing is probably due to lack of high byte termination in the
BA353 for wide devices. The RZ1DB-VW is a wide device, designated by the -VW.
Narrow devices have a -VA suffix, for example RZ29B-VA.

If you used your SCA to 50 pin adapter in the VAXstation and it 'worked', the
SCA adapter is probably supplying the high byte termination for the RZ1DB drive.

The rule of thumb is that narrow devices generally will function correctly in a
wide backplane, but wide devices do not work in narrow ones.

The bottom line is that your RZ1DB-VW SBB isn't compatible with the BA353.

Jeff Campbell
n8wxs@arrl.net