68 pin SCSI on 50 pin SCSI bus

68 pin SCSI on 50 pin SCSI bus

Post by stuie_norr » Mon, 19 Jul 2004 06:52:53

Hello All,

I have an Alpha station 200i 4/100.

I am finding it very hard to get 50 pin SCSI disks that are good enough to use.

I have several RZ29 drives with a 68 pin interfaces.

If I buy a female 50 pin to female 68 pin SCSI adapter can I connect this adapter to
the mother board and run the 68 pin drives. The 68 pin SCSI cable I have states
that all the drives including the last must be unterminated.

From a gender point of view this will work.

Will this work from a SCSI point of view?


68 pin SCSI on 50 pin SCSI bus

Post by Jefferson » Mon, 19 Jul 2004 08:33:00

BlackBox sell internal SCSI adapters for HDD's.

We have bought 80pin -> 50pin & 68pin -> 50pin adapters that simply plug
onto the back of the drive.

Haven't used them on Alpha's though.



68 pin SCSI on 50 pin SCSI bus

Post by Hans Vlem » Mon, 19 Jul 2004 21:53:33

"Stuart Norris" < XXXX@XXXXX.COM > schreef in bericht

adapter to

In the world of SCSI anything goes, but the answer to your question is
probably: yes.
I have a QUANTUM ATLAS_V__9_WLS disk fitted with an adapter like you
male 68-to-male 50 pin SCSI and it works in a Digital Server 5305 (similar
to an AS1200)
uner VMS 7.3 and in an expansion box (the one with the VAXstation 3100
look) attached
to a VAXstation 4000-90A also running VMS 7.3.
A company I found very reliable and knowledgeable is McPricebreakers on


The product listed above is somewhat clumsy, I prefer the straight converter


68 pin SCSI on 50 pin SCSI bus

Post by Dr. Dwee » Mon, 19 Jul 2004 22:31:32

I tried it once 68--> 50 and the Alpha firmware failed to recognise the
drive. YMMV


68 pin SCSI on 50 pin SCSI bus

Post by Paul Repac » Tue, 20 Jul 2004 00:44:22

XXXX@XXXXX.COM (Stuart Norris) writes:

Some will, some won't... Not being funny, SCSI and `standard' don't
belong on the same page...

But, RZ29s on a 16 bit SCSI bus with 16 bit terminators on the cable
can be pluged via a 68-50 converter into a narrow controller and work.

Some drives will not, they will only work on a 16 bit bus as they
don't use 8 bit x'fers, others are quite happy to have only an 8 bit
bus connected and disable the unused 8 data lines and the extra
address line.

It is called `Industry Standard'

Paul Repacholi 1 Crescent Rd.,
+61 (08) 9257-1001 Kalamunda.
West Australia 6076
comp.os.vms,- The Older, Grumpier Slashdot
Raw, Cooked or Well-done, it's all half baked.
EPIC, The Architecture of the future, always has been, always will be.

68 pin SCSI on 50 pin SCSI bus

Post by David J Da » Tue, 20 Jul 2004 02:01:22

It is important to remember that neither of the "S"'s in "SCSI"
represent the word "standard". "SCSI" is an acronym for "Small Computer
Systems Interface". It is a set of specifications, not a "standard".

The more common interpretations of the SCSI specification are de-facto
standards by token of their commonness and ubiquity, and are not
prescribed by any standards body recognized industry-wide, AFAIK.


68 pin SCSI on 50 pin SCSI bus

Post by David Frob » Tue, 20 Jul 2004 02:05:15

I'd agree with Hans. However, since you have wide SCSI drives, why not look
around for a wide SCSI interface. I haven't done it, but I'd think that a PCI
card would work in the AlphaStation.


David Froble Tel: 724-529-0450
Dave Froble Enterprises, Inc. Fax: 724-529-0596
DFE Ultralights, Inc. E-Mail: XXXX@XXXXX.COM
170 Grimplin Road
Vanderbilt, PA 15486

68 pin SCSI on 50 pin SCSI bus

Post by Skylar Tho » Tue, 20 Jul 2004 10:09:00

It should, since SCSI is fairly implementation-independent. Just make sure
your SCSI IDs are all < 7.

-- Skylar Thompson ( XXXX@XXXXX.COM )
-- http://www.yqcomputer.com/ ~skylar/

68 pin SCSI on 50 pin SCSI bus

Post by Barry Trea » Tue, 20 Jul 2004 13:17:51

and make sure that if you have a mix of 8 and 16 bit devices in the
chain, that the 16 bits are after the 8 and that you are getting good
device termination power for the termination.



Barry Treahy, Jr E-mail: XXXX@XXXXX.COM
Midwest Microwave Phone: 480/314-1320
Vice President & CIO FAX: 480/661-7028

68 pin SCSI on 50 pin SCSI bus

Post by ralf.gaert » Tue, 20 Jul 2004 19:18:38

Unfortzunately, it isn't that simple. www.paralan.com has a nice
overview about the current SCSI standards. From what you write I
expect that you have "wide" SCSI drives. If you have also a "wide"
SCSI controller in you Alpha, than there will be no problem, but since
you mention 50 pin I guess that you have a "narrow" SCSI controller.
Adaptec sold an adapter to connect 8 bit (narrow) and 16 bit (wide)
devices, where the unused connections are proper terminated. The
simplest way to use you drives would be to get a used ultra-wide SCSI

68 pin SCSI on 50 pin SCSI bus

Post by Hans Vlem » Wed, 21 Jul 2004 02:13:34

"David Froble" < XXXX@XXXXX.COM > schreef in bericht


If a drive is not recognized then high byte termination is more often than
not the culprit.
The supplier listed above has special interfaces that deal with high byte
The terminator is an optional part. It's tiny, plugs in on the converter
board and is around $10.

68 pin SCSI on 50 pin SCSI bus

Post by healyz » Wed, 21 Jul 2004 03:24:45

This would be the way to go. I temporarily had the KZPBA from my PWS 433au
installed in an AlphaStation 200 4/233 while I thought the PWS 433au was
dying. It worked just fine. The downside with an AS200 is that you only
have two PCI slots. This means choosing between DE500, KZPBA, and a
Graphics card (for me it wasn't a rough choice as I didn't need the

I've used the 80-pin to 68-pin converters to attach an SCA drive to my PWS.
While I honestly don't know, I suspect that 68 or 80-pin to 50 pin coverters
will work, but that it is likely to depend on the manufacturer. I know if
you're trying to connect a 50-pin device to a 68-pin connector (such as on
an AlphaStation 500) you have to find an adapter with Active termination.

Something else to consider is an EIDE to 50-pin SCSI converter. I've not
used one, but people here have had success with these, the downside to them
is that they don't support Volume Shadowing.


68 pin SCSI on 50 pin SCSI bus

Post by Bill Norto » Thu, 22 Jul 2004 02:51:28

The BA364 desktop 4-drive enclosure is handy for this situation. I have
one containing three RZ29B's connected to the LD50 SCSI connector on a
VAXStation 4000 and it works fine. Each drive has its own ID
dipswitches so you can avoid conflicts with the internal drives.

68 pin SCSI on 50 pin SCSI bus

Post by Island Com » Thu, 22 Jul 2004 21:42:58

We have been thtough this a number of times

You can do this with OLDER UW and U2 Disks
U3 Drives do not like being bumped down to 8Bit

On many wide drives, you need to diable FW negotiation (most IBM drives have
Compaq used IBM drives in their faster storageworks narrow canisters with
the FW NEgotiation disabled by default

We sell the 50 to 68 pin converters here alsoo which we use all the time on
Alpha for $15
50pin Narrow Female to 68P Wide Female


David B Turner
Island Computers US Corporation
2700 Gregory St., Suite 180
Savannah GA 31404
DIRECT#: 912 232 1729
Tel: 912 447 6622
Fax: 912 201 0402

adapter to

68 pin SCSI on 50 pin SCSI bus

Post by John Santo » Tue, 27 Jul 2004 06:48:25

I bought a bunch of RZ28's on Ebay (for about $5/each, I think... it
was a while ago.)

They were in storageworks cans. I wanted to install one in my
AlphaServer 200 4/100 (just like the Stuart's, I think.)

I opened one up, and found it had an internal 68-pin connector
and cable. (I've since dismantled at least one other and found
it was a 50-pin connector and cable. They were all labled RZ28-VA
on the outside, IIRC.)

I got a 50-pin to 68-pin adapter at Microcenter, which cost about
$10-15, I think (more than the drive did), and installed it on the
drive and then connected the 50-pin cable to it. Works fine.

This is a black plastic about 2 inches wide, 1/2 inch thick with
a male 50-pin connector on one side and a female 68-pin connector
on the other. It makes the drive about 1/2 inch deeper (front-to-
back) when plugged in, but there was room behind the drive in the

It should work fine with an RZ29 as well, but you might have
cooling problems. I suppose you could always duct-tape a fan
to the outside of the case to blast cool air through it, if
necessary. I think there is plenty of power to drive it, but
you should check the manual. (I can look at the specs tomorrow,
if you don't have one.)

I'm sure this isn't supported, but if you are mucking around with
RZ29's and A/S 200's, you probably don't care!

Good luck.

John Santos
Evans Griffiths & Hart, Inc.
781-861-0670 ext 539