I just added two SMD drives to my 4/260.  They are:

xyc0 at vmes0 addr 0xffffee40 vec 0x48 pri 3: Xylogics 450/451
xy0 at xyc0 drive 0: ready (drive type 2)
xy0: <Fujitsu-M2372K cyl 743 alt 2 hd 27 sec 67>, pcyl 745
xy0: 656MB, 743 cyl, 27 head, 67 sec, 512 bytes/sec
xy1 at xyc0 drive 1: ready (drive type 3)
xy1: <Fujitsu-M2361 Eagle cyl 840 alt 2 hd 20 sec 67>, pcyl 842
xy1: 549MB, 840 cyl, 20 head, 67 sec, 512 bytes/sec

Yeah, the model numbers match what is on the drive, but I don't have
much info about the drives themselves.  They spin up and don't fault...
everything seems okay.

I also got some DC600A tapes for my Wangtek 5099EN24 tape drive
(connected to a Sun3 SCSI controller through some Emulex board which is
detected as a rogue SCSI device).  Then I spent some time playing with
the system.  I got some error messages that are disturbing.

First of all, the following seems to happen regularly:
ie0: DMA underrun
These happen occasionally.  They are in groups with messages a few
seconds apart.  It seems to me that network activity is halted or very
slow during that time.      

After a complete write to tape I get the following message:
st0(si0:4:0): illegal request, data = 34 00 08
During a long write I also got stuff like:
st0(si0:4:0): soft error (corrected), data = 18 00 08
These don't really seem to matter, but I'm just wondering if there's
anything to be concerned about here and whether getting 8 of the soft
errors in a 30 meg file is okay.
BTW.  DMA, reconnection and interrupts are enabled on the SCSI
controller. 

Now about the disks:  First of all I couldn't even access the M2372K
(the Eagle worked fine).  I could read the disklabel but when I tried to
mount something I got lots of errors like:
xy0a: read 0/1/6: Header not found [still trying, new error=Disk
sequencer error]
xy0a: read 0/1/6: Disk sequencer error [still trying, new error=Header
not found]
This keeps going on and on.  Mount actually terminates and the disk is
mounted but not mounted.  Lots of twisted things happen here.
The boot ROM refused to read most of it either.
However, through some umm... magic (I didn't do anything) it now works. 
I can mount xy0 and even boot SunOS 4.1.3 off it.  However, I still get
these errors:
xy0d: read 73/1/40: Disk sequencer error [recovered in 1 tries]
I'm not sure what they mean, but everything seems to work okay.  I'm not
sure if the fact that I have write protect on is causing this.  

What about SMD termination?  Could I be doing something wrong?  The
M2372K is the second drive in the chain, and it just has ribbon cables
going in.  I assume that the termination must be internal.  The command
cables are twisted pair ribbons.  The data cable is just a plain
ribbon.  That is worrisome... these cables are in an area which must
have high levels of EM.interference (computers, disk drives and lots of
other cables)      
 

|  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  |