I've been trying to use two RZ55 and one RZ56 drive with my VAXen.  I've
tried various combinations with VS3100m38 SCSI, an SQ739 and some
unknown Dilog controller (labels have been removed and firmware doesn't
say what it is.  SQ7 is on the board, but it seems that a label with the
continuation of the number should come after it)

So far I have only been able to get one particular RZ55 working with the
unknown Dilog controller.  With the other two drives and the unknown
Dilog controller, I get can't write block errors when doing newfs or
fsck.  If I do dd, some bytes get corrupted.  
With the SQ739 and any of the drives reads work perfectly, but bits get
flipped on writes and there are no error messages.  With the VS3100m38,
the kernel waits a long time when it should be detecting the drive.  It
prints no REQ for next phase error messages and eventually gives up.  At
first I thought that VS3100 SCSI support was totally broken, but it at
least detects the RX23 SCSI interface.

Now, the drives are okay.  I've tested them with rzdisk and scu on a
DECstation 3100 running Ultrix 4.4.  Later I tested them with sformat
under Linux on a PC.  There are *no* errors.

I had some problems getting the drives to work with Linux.  Basically,
Linux would lock up when trying to detect them.  I finally reallized
that you *must* do an SDTR (synchronous data transfer request)
negotiation with the drives before they'll even work in asynchronous
mode.  Now, I'm wondering if that's why the drives don't work with the
VS3100.  I'm also wondering if that's why they fail with the Dilog SCSI
controllers.  

Is there some way to get the drives to default to asynchronous mode? 
How about turning on parity checking?  (I assume that parity checking is
off if bits get flipped like that)  I assume that I need info on
drive-specific mode page settings.  Can anybody help?

-- 
|  Boris Gjenero <bgjenero@undergrad.math.uwaterloo.ca>              |
|  Home page:  http://www.undergrad.math.uwaterloo.ca/~bgjenero/     |
|  "Luke, you're going to find that many of the truths we cling to   |
|  depend greatly on our own point of view." - Obi-Wan Kenobi, ROTJ  |