[comp.sys.dec] Is DEC RZ23 real SCSI?

lancelot@spock.UUCP (Thor Lancelot Simon) (06/03/90)

<Cut this!>

I have an overabundance of DEC RZ23 105-meg drives which are intended to go in
a few DecStations that won't arrive for a while.  (Please keep in mind that as
far as warranty goes, this article is altogether hypothetical.)  They look a
bit like Quantum 105S, and I figured that they probably were, with the firmware
changed so that they report manufacturer DEC, drive type RZ23.  However, upon
replacing the Q80 in my Amiga HD box with one of these, a 'Drive Scan' from my
SCSI format&tools package didn't show up.  Didn't even flash the drive light, 
like it does on everything else I've hooked up to it.  I know one can hook up
standard SCSI drives (tapes, scanners, and CDROMS as well, though we haven't 
tried to write drivers yet) to a DECStation, and it will pick them up if you
do a 'scsi pb' (drive scan) from the boot prompt, but do the DEC drives have
some abnormal query format only understood by other DEC products?  If so, could
I modify my amiga software to speak it, or does it have to be done at the 
hardware level (pull a line low or some such oddity)?

Just for reference, my Amiga setup is an A500 with a Xetec Fasttrak controller.
I have checked all the cables involved, and my controller can talk to just 
about anything else I hook up to it, except the RZ23s in question.  I'm using
the utilities that came with the controller, one called 'SCSI Tools', and one
called 'Partitions'.  The light on the RZ23 does flash a few times when I power
up my Amiga, but only then.



*******************************************************************************
*Thor Simon             * Okay, just a little pin-prick...There'll be no more-*
*lancelot@spock.UUCP    * Aieeeeaaaugh!-but you may feel a little _sick_.     *
*uunet!hsi!yale!lancelot*   ---Pink Floyd                                     *

jg@zorch.crl.dec.com (Jim Gettys) (06/04/90)

As far as I know, we do everything legit, for the standard
command set (or whatever the SCSI terminology is for the
command set disk and tape devices are supposed to implement).
And while I'm not one of our SCSI experts, I don't think
we've done anything strange to the drives we use, other than
get them to work properly and put a DEC label in the ROM...

Experience has shown, however, that SCSI is far from the
tightest specification in the world.  When we started hooking up
other SCSI devices to DECstations, there was about a 50% chance
they would work (to my knowledge, it our case, it was always microcode
problems with the SCSI peripherals; in your case, it could be either
the drive or your controller); this percentage has
been increasing with time, as people get their implementations
conformant to the specification, and the specification gets better
understood by the implementors  (moral is:  KISS...  SCSI violates
this rule...).

But your experience is not all that unusual, from what I've
seen, with hooking up new devices on a SCSI...  Sigh...

Of course, make sure you have the SCSI unit number set to
something reasonable...  I once had a RZ55 and an RZ23 set to the
same address on my DS3100, and shall we just say that the machine
acted wierd.....  Almost booted up multi-user, but not quite...
			- Jim

leech@jason.cs.unc.edu (Jonathan Leech) (06/04/90)

In article <5454@crltrx.crl.dec.com> jg@zorch.crl.dec.com (Jim Gettys) writes:
>When we started hooking up
>other SCSI devices to DECstations, there was about a 50% chance
>they would work...

    Is there a list of non-DEC SCSI devices that are known to work
with DECstations?  How might we obtain it, if so?
--
    Jon Leech (leech@cs.unc.edu)    __@/
    ``Thus Mathematics helps / our brains and hands and feet
      and can make / a race of supermen out of us.''
	- The Education of T. C. Mits

wherry@alazif.enet.dec.com (bradley g wherry) (06/04/90)

In article <1990Jun2.213812.13909@spock.UUCP>, lancelot@spock.UUCP (Thor
Lancelot Simon) writes:

<stuff deleted>

> bit like Quantum 105S, and I figured that they probably were, with the
firmware
> changed so that they report manufacturer DEC, drive type RZ23.  However, upon
> replacing the Q80 in my Amiga HD box with one of these, a 'Drive Scan'
from my
> SCSI format&tools package didn't show up.  Didn't even flash the drive
light, 
> like it does on everything else I've hooked up to it.  I know one can hook up

The RZ23 is really SCSI, it is honest.

The drive is not a Quantum 105S but rather a Conner 105 MB drive.  yes
the drive 
does report the drive type as RZ23.  The drive
does not spin up when power is applied.  I believe you need to send an SCSI
INIT command to spin up the drive.  They don't spin-up by default or rather
the DEC version does not do this by default.

<stuff deleted>


> called 'Partitions'.  The light on the RZ23 does flash a few times
when I power
> up my Amiga, but only then.

not being really familiar with the drive I could only speculate that its the
power up diags which are blinking the light.  

--
brad wherry                |  Ex ignorantia ad sapientiam; 
wherry@alazif.enet.dec.com |     e luce ad tenebras.

jg@zorch.crl.dec.com (Jim Gettys) (06/04/90)

To be honest, I don't know if we (Digital) are
keeping such a list anywhere.  I'd expect it to be
somewhere in the sales or marketing organizations,
if anywhere.

Also keep in mind that "known to work" is not the
same level of confidence that we have in the devices
we sell, which get extensive internal and external
testing in the qualification process.

The general problem is quite hard, since it often
involves revisions of firmware for each device,
which can, of course, even get broken from revision
to revision.
			- Jim

wallace@oldtmr.enet.dec.com (Ray Wallace) (06/04/90)

In article <1990Jun2.213812.13909@spock.UUCP>, lancelot@spock.UUCP (Thor
Lancelot Simon) writes... 
> However, upon
>replacing the Q80 in my Amiga HD box with one of these, a 'Drive Scan' from my
>SCSI format&tools package didn't show up.  Didn't even flash the drive light, 
>like it does on everything else I've hooked up to it.
Can you tell if the drive actualy spun up or not? I've read that the RZ's need
a "spin up SCSI command" sent to them when ever you turn them on. 

---
Ray Wallace		
		(INTERNET,UUCP) wallace@oldtmr.enet.dec.com
		(UUCP)		...!decwrl!oldtmr.enet!wallace
		(INTERNET)	wallace%oldtmr.enet@decwrl.dec.com
---

minow@mountn.dec.com (Martin Minow) (06/04/90)

First, I would want to make it clear that I do not recommend that you
connect a Dec RZ23 to a non-Dec computer.

The RZ23 is a normal SCSI device. Drive formatters, however (I'm only
familiar with the Macintosh) do a "device inquiry" to see what they're
connected to.  The RZ23 responds with something like "DEC RZ23". If your
drive formatter is looking for "QUANTUM P105S", it will fail with "don't
understand this drive."

Also, vendors (not specifically Dec) often add proprietary microcode to
the raw hardware.  For example, they may need to control certain kinds of
error handling.  The Ansi standard reserves certain "mode select" and "mode
sense" pages (records) to the manufacturer.  Some vendors (again, not
specifically Dec) send a Mode Sense command and expect to see "Copyright 1990
Mumble Corporation".

In the PC market, when you buy a drive from an end-user vendor, it generally
comes with a formatting package that understands its specific quirks.

Martin Minow
minow@thundr.enet.dec.com
The above does not represent the position of Digital Equipment Corporation.

abstine@image.soe.clarkson.edu (Arthur Stine) (06/04/90)

From article <1990Jun2.213812.13909@spock.UUCP>, by lancelot@spock.UUCP (Thor Lancelot Simon):
> <Cut this!>
> 
> I have an overabundance of DEC RZ23 105-meg drives which are intended to go in
> a few DecStations that won't arrive for a while.  (Please keep in mind that as
> far as warranty goes, this article is altogether hypothetical.)  They look a
> bit like Quantum 105S, and I figured that they probably were, with the firmware
> changed so that they report manufacturer DEC, drive type RZ23.  However, upon
> replacing the Q80 in my Amiga HD box with one of these, a 'Drive Scan' from my

The RZ23 and 22 are Conner drives... the RZ55 is a Micropolis to the best
of my knowledge.

-- 
Art Stine
Sr Network Engineer
Clarkson U
ABStine@CLVMS.Clarkson.Edu

mjacob@wonky.Eng.Sun.COM (Matt Jacob) (06/04/90)

In article <5454@crltrx.crl.dec.com> jg@zorch.crl.dec.com (Jim Gettys) writes:
>Experience has shown, however, that SCSI is far from the
>tightest specification in the world.  When we started hooking up
>other SCSI devices to DECstations, there was about a 50% chance
>they would work (to my knowledge, it our case, it was always microcode
>problems with the SCSI peripherals; in your case, it could be either
>the drive or your controller); this percentage has
>been increasing with time, as people get their implementations
>conformant to the specification, and the specification gets better
>understood by the implementors  (moral is:  KISS...  SCSI violates
>this rule...).

Weak, buddy. Real weak. This would have been a truer statement 3-4
years ago, but not for the last couple of years.

-matt jacob
 Sun Microsystems

leech@ornat.cs.unc.edu (Jonathan Leech) (06/04/90)

In article <136580@sun.Eng.Sun.COM> mjacob@wonky.Eng.Sun.COM (Matt Jacob) writes:
>In article <5454@crltrx.crl.dec.com> jg@zorch.crl.dec.com (Jim Gettys) writes:
>>Experience has shown, however, that SCSI is far from the
>>tightest specification in the world. (...)
>Weak, buddy. Real weak. This would have been a truer statement 3-4
>years ago, but not for the last couple of years.

    Can we assume, then, that any SCSI drive manufactured in the last
couple of years will work correctly when connected to a Sun SLC?
(This is not a snide question; I'm thinking about buying either an SLC
or a DS2100, and can't afford Sun/DEC mass storage prices).
--
    Jon Leech (leech@cs.unc.edu)    __@/
"We were driving along, minding our own business, when there was a
 sudden flash of blue light which blotted out the stars. I thought it
 was a nuclear bomb going off and despaired for my career." - Keith Hughes

jg@zorch.crl.dec.com (Jim Gettys) (06/04/90)

>>Experience has shown, however, that SCSI is far from the
>>tightest specification in the world.  When we started hooking up
>>other SCSI devices to DECstations, there was about a 50% chance
>>they would work (to my knowledge, it our case, it was always microcode
>>problems with the SCSI peripherals; in your case, it could be either
>>the drive or your controller); this percentage has
>>been increasing with time, as people get their implementations
>>conformant to the specification, and the specification gets better
>>understood by the implementors  (moral is:  KISS...  SCSI violates
>>this rule...).

>Weak, buddy. Real weak. This would have been a truer statement 3-4
>years ago, but not for the last couple of years.

>
>-matt jacob
> Sun Microsystems

Boy, it looks like you don't like to read....

If you read my statement above, you'll see that I was talking about several
years ago, and noted that the percentage has been increasing with time.
And it was a very small sample. (statistics of small numbers....)

Most of the problems we saw were of the form:

Disk firmware has timing window that only a fast machine can hit...
Drive might generate error or hang after pounding on it for some hours.

Getting solid implementations of complex specifications is always
difficult.

Are you claiming that Sun makes slow machines and slow SCSI implementations
that don't see that kind of problem?  :-).  Sun certainly didn't
build such fast machines 18 months ago... :-).
				- Jim

steven@pacific.csl.uiuc.edu (Steven Parkes) (06/04/90)

|>     Can we assume, then, that any SCSI drive manufactured in the last
|> couple of years will work correctly when connected to a Sun SLC?
|> (This is not a snide question; I'm thinking about buying either an SLC
|> or a DS2100, and can't afford Sun/DEC mass storage prices).

The latest I heard on this group was that although non-DEC disks could be
used for data on 21/31/5k's, they couldn't be used for booting.  Is this still
the concesus?

Also, regarding prices, University people should ask their DEC rep's about
consortium prices -- maybe not the best, but at near half off, they're very
good for what you get.

mjacob@wonky.Eng.Sun.COM (Matt Jacob) (06/04/90)

In article <5461@crltrx.crl.dec.com> jg@zorch.crl.dec.com (Jim Gettys) writes:
>>>Experience has shown, however, that SCSI is far from the
>>>tightest specification in the world.  When we started hooking up
>>>other SCSI devices to DECstations, there was about a 50% chance
>>>they would work (to my knowledge, it our case, it was always microcode
>>>problems with the SCSI peripherals; in your case, it could be either
>>>the drive or your controller); this percentage has
>>>been increasing with time, as people get their implementations
>>>conformant to the specification, and the specification gets better
>>>understood by the implementors  (moral is:  KISS...  SCSI violates
>>>this rule...).
>
>>Weak, buddy. Real weak. This would have been a truer statement 3-4
>>years ago, but not for the last couple of years.
>
>>
>>-matt jacob
>> Sun Microsystems
>
>Boy, it looks like you don't like to read....

First of all- apologies for being so acerbic. And yes- I didn't read
it as carefully as I might- I was dialed in from home (23 line tty
pages don't latch up in my mind like they should...*sigh*)

>
>If you read my statement above, you'll see that I was talking about several
>years ago, and noted that the percentage has been increasing with time.
>And it was a very small sample. (statistics of small numbers....)
>
>Most of the problems we saw were of the form:
>
>Disk firmware has timing window that only a fast machine can hit...
>Drive might generate error or hang after pounding on it for some hours.
>
>Getting solid implementations of complex specifications is always
>difficult.

True.

>
>Are you claiming that Sun makes slow machines and slow SCSI implementations
>that don't see that kind of problem?  :-).  Sun certainly didn't
>build such fast machines 18 months ago... :-).
>				- Jim


Speed of the CPU or the Host Adapter is largely irrelevant. A good and
careful s/w implementation of the transport layer (Host adapter driver)
can undertake various strategies to make up for deficient hardware.

-matt

p.s.: Let me present my credentials, which you can then use specifically 
defame me with: I am 99% responsible for the SCSI S/W on the SparcStation-1
(and its clones, e.g., SLC, etc.).

leech@homer.cs.unc.edu (Jonathan Leech) (06/04/90)

In article <1990Jun4.160328.22033@ux1.cso.uiuc.edu> steven@pacific.csl.uiuc.edu writes:
>Also, regarding prices, University people should ask their DEC rep's about
>consortium prices -- maybe not the best, but at near half off, they're very
>good for what you get.

    DEC Consortium  Random PC Week Vendor
    --		    --
    RZ23 $1000	    Conner CP3100   $565
    RZ24 $1500	    Conner CP3200   $875

    But for a major manufacturer, I suppose that is pretty good.  I'm
certainly not flaming DEC for setting the prices they do, just
exploring far cheaper alternatives.
--
    Jon Leech (leech@cs.unc.edu)    __@/
    "I met a wonderful new man. He's fictional, but you can't have everything."
	- Cecelia, _The Purple Rose of Cairo_

jg@zorch.crl.dec.com (Jim Gettys) (06/05/90)

Matt, I think we are converging on general agreement...

Short of making signals run more slowly, or slowing down interrupt
response (something I doubt you'd be willing to do), the kind of
problems we were seeing weren't fixable in host software.

Sounds like you've had somewhat better luck than we did (or your
machines are slower :-)).

In any case, general experience shows that disk incompatibilty problems
have been diminishing with time, and are much less a problem than they
once were.  I've heard much more often recently of things plugging in
and working fine than was true 20 months ago.

And to answer Steven Parkes question about booting...

Ultrix boots just fine off of other people's disks.  The only problem I
am aware of is doing an initial installation of Ultrix onto someone
else's disk is more involved (since Ultrix won't know anything about the
disk, at the time it needs to).  Even this can be worked around if you
are sufficiently motivated/informed; it is the same procedure needed
when installing on an RZ56 or RZ57 under Ultrix 3.0 or 3.1, which won't
be able to recognise the disks.

Generally, the easiest solution is to hook up the other disk to an
existing machine, and set the disk up there, and recable, rather than do
a fresh install.
				- Jim