Subject: DN3k/4k add-on disks: solution! (long)
From: [email-masked] (Jeff Koehler)
Date: Thu, 30 May 91 14:17:50 EDT
Newsgroups: comp.sys.apollo

Subject: DN3k/4k add-on disks: solution!	(long)

	All information I have received from HP/Apollo and Mentor is 
	that YOU CANNOT ADD SCSI DISKS and access them transparently.
	     ---------------====------  (applies to DN3500/DN4000 only)

	Here is a method of adding EDSI disks.

	Caution:  This posting is in no way connected to HP/Apollo,
		  Mentor Graphics, or any service organization involved 
		  with these companies.  The suggestions embodied herein
		  are also not in any way supported by the author,
		  although the methodology has provided an add-on 780
		  MByte disk that has been running smoothly for weeks.

	Abstract: I have seen enough of the questions about how
		  to add disks to HP/Apollo DN3500/4000 nodes; it
		  is time to lay the rumors to rest.  Sorry, this only 
		  covers these two models.

		  To add EDSI disks, and you must add them
		  externally, since there is no room in the original
		  chassis for additional (full height) drives.  This 
		  article describes how I added an external 760 MB 
		  disk subsystem to a DN3500.  It applies equally well 
		  to 380 MB drives, and/or DN4000's, with minor changes.

		  The HP/Apollo Multiple Disk Expansion Module (MDEM)
		  manual is referenced heavily throughout this article.
		  It is strongly suggested you order it before you attempt
		  to install your own, HP/Apollo's, or Mentor's expansion
		  modules.  Ordering instructions for this manual are 
		  included in this article.  The manual specifies you must
		  have the following revisions of software to operate the
		  subsystem(s) (page 1-3):

			SR9.7.1 and media type SFW-PSK3-MED9
			SR10.1  and media type SFW-PSK4-MED10

		  My SR10.1 installation needed no additional patches.

	 ---->>>  Note: you must add a disk of the same size as the
		  existing internal disk. (380 & 380, 760 & 760).
		  You may mix Micropolis and Maxtors, but both must
		  be of the `fast actuator' type.  The disks must
		  be EDSI, and are controlled from the EDSI ports
		  of the WD7000 controller (required).

	 ---->>>  While SCSI disks may be electrically compatible with 
		  these machines, I was unable to describe their existence 
		  to Domain/OS, which pretty much renders them useless.
		  You can, however, add 8mm and 1/4 inch tape drives on
		  the WD7000 SCSI port (the manual covers this, too).

	----- ----- ----- ----- ----- ----- ----- ----- ----- -----  -----

	This article may contain dated material.  It was first released
	on May 30, 1991 to the Internet News group `comp.sys.apollo'
	by J.A.Koehler.  It is hereby released to the public domain.

	================================================================
		   Introduction and Background ... part 1
	================================================================

	I am posting this in response to the apparent lack of technical
	information available from Mentor and HP when attempting to 
	increase the disk capacity of an HP/Apollo  DN4000 or DN3500.  
	It appears they felt that the fewer technical details they released, 
	the more pre-disposed you would be toward buying their turnkey disk 
	subsystems, at what I consider inflated rates.  To illustrate, 
	compare the confustion in this News group to adding a second disk 
	to an IBM PC compatible -- that information is pretty much 
	considered public knowledge.  Most of the information was construed 
	from HP/Apollo and Mentor manuals and service people, and this 
	compendium is intended to save the general public from spending days 
	on the phone chasing down all of the loose ends.
	
	I have added a 760 MB Maxtor to my DN3500 and it has passed SAX 
	and all of my ad hoc regression tests.  The cost was approximately
	1/4 of the retail price (see below for more on costs).  A word of
	caution: I have only been running this configuation for about 3
	weeks now.  My primary use for it is vendor libraries and software,
	so if it does fail, my data loss isn't irreversible, only irritating.
	Apply appropriate scrutiny to the level of confidence you will
	entrust upon my `suggestions'.
	
	If you are at all interested in performing this yourself, save 
	this article in a file (with the command 's file') and print it.
 
	Please DO NOT expect me to support your add-on modules in any 
	manner -- I am just as busy as you are.  If you are NOT a brave and 
	daring hardware hacker, buy the expansion module from Mentor or 
	HP -- my method will probably take up a considerable amount of 
	your valuable time.

		    Estimated costs (760 MB, 650 MB formatted)
		-----------------------------------------------------
		$10,000 un-official Mentor price (not quoted)
		$ 2,675 piece-parts price, plus $100 for chassis
		$ 2,115 if you use non-HP cables and `find' a chassis
		-----------------------------------------------------

	For those of you on a shoe-string budget, that $2,100 price tag
	looks pretty appealing.  The relative price of adding the third
	and fourth disks may be less attractive, for you must purchase 
	a second WD7000 controller card in addition to the other parts.
	I decided it would be more cost effective to resort to this only
	after all of our nodes has a second external disk installed.

		----- 		----- 		----- 

	The important issues to remember are:

	Why external? 	There isn't room to add another disk inside
			the chassis.  An external subsystem requires 
			shielded cable, etc. for EMI reasons (and the
			fact that users may walk on the cable!)

		DN3500: If you already have a WD7000 controller, I think
			you are all set.  If you don't, I am not sure what 
			rev you need to support it.  You should probably
			call HP regardless, to determine whether it is 
			possible with your configuration.

		DN4000:	My customer service rep said you need rev 25 or
			later on your motherboard.  You probably DON'T have
			this on your DN4000, and it costs a few thousand
			to have Mentor upgrade it.  I avoided this situation
			by adding it to our DN3500 instead.  Again, you
			should contact HP or Mentor to check on the 
			compatability with your particular configuration.

	IMPORTANT:  1)	You must add an external disk OF THE SAME SIZE as
			the internal one.  This applies to any of these
			configurations.

		    2)	You must have a Western Digital 7000v SCSI/EDSI
			controller.  Note: WD customer service claims this
			is a special OEM version of the 7000 (hence the 'v').
			I was lead to understand that the non-OEM version
			doesn't support both SCSI and EDSI, and the tech-
			nician on WD's customer service line was unsure of
			the actual differences.  If your machine came with
			one, its probably the right one.  If you are trying
			to add a second controller, Better call HP to be sure
			you get the correct model.

		    3)	You need NOT purchase a second controller to add 1 
			external drive.  You MUST purchase a second con-
			troller to add a third and fourth drive.

		    4)	You must use the fast-actuator drive types (either
			Micropolis or Maxtor).  The trailing 'E' on a Maxtor
			indicates a fast actuator drive; I am not sure of
			the Part number for the Micropolis, but you can check
			on the internal one in your DNxx00 for an example.
			As long as they are the same capacity, you may mix the
			Micropolis and Maxtor drives on the same controller.

		also:	You may use the SCSI bus to add a 1/4 tape drive
			or an 8mm tape drive.  The manual describes these
			in detail, too (but I don't -- I haven't tried it).

	For those of you that are serious about this, I whole-heartedly sug-
	gust you order the manual and take a look for yourself.  Be sure to
	get a quote from HP or Mentor to justify the cost savings involved,
	since you will have to remind yourself it was worth the savings to
	not buy the `turnkey' alternative.

	Here is the manual number:	

           D-16411-0	manual For Multiple Disk Expansion 
			Module (MDEM or DEM).
			(obsolete Apollo number 016411-A00)

	The cost is $6.00; minimum order is $20.00; so find something else
	you were going to order from them or you'll end up overpaying.

	This is a SPECIAL ORDER item and is available from your local
	ORDER PROCESSING DESK.  Contact your HP sales rep to find the
	location of the order processing desk nearest you.  HP spare
	parts will be unable to help you out on this item.

	The manual gives you the complete installation instructions
	with the exception of how to INVOL and MOUNT it (some hints are
	provided in part 4 of this article).

	================================================================
			What I have learned ... part 2
	================================================================

	Now, let's discuss what ISN'T covered in the manual -- the Disk
	Expansion Module itself (after all, you are saving a bundle, you
	must be prepared to provide some elbow grease).  If you are familiar
	with the industry standard method of configuring MFM, RLL and EDSI
	disks, you are almost there.  The secret lies in the 'shared' control
	(at least I think they are control) lines:

	  WD7000 controller                +----------------+
	+------------+            /========>  ESDI  drive 0 |
	|            |   drive 0  ||       |  (internal)    |
	|    20 pin ==============/        +----||----------+
	|            |                          ||
	|            |                 +---+    || unshared 34 pin cable
	|            |   shared        |   |    ||
	|    34 pin ===================|   |====/
	|            |   drive 1       |PCB|
	|    20 pin ===================|   |--\        80 pin external
	|            |                 |   |   |=====================
	+------------+                 |   |--/         (12837-001)
                                       +---+
				       012824

	The 80 pin external cable will go to the external chassis and
	mate with another 'PCB' (012824) WHICH YOU WILL INSTALL.  This
	'PCB' has no active components, but provides a neat and easy 
	method of interconnecting the 80 pin shielded external cable to
	both chassis.  It is debatable whether the PCB is worth the 
	$140, but unless you intend to produce your own PCBs, you are
	left with little choice.  I'm sure both EMI and connection 
	integrity were of major concern when designing this interface,
	and this PCB provides a sturdy segue from external to internal
	cabling.

	It is probably worth mentioning here that the screws and brackets
	itemized in the parts list are well worth the money.  If you are
	truly a `Scrooge', then buy 1 bracket and manufacture the rest, using 
	it as a template (they are really just PC-type brackets with a 
	mounting hole machined specifically for the Honda connector).  

	The Honda connector itself is one of the best I have seen; its 
	locking mechanism is quite sturdy and passes my psuedo-rigorous 
	tests at yanking it out.  You will probably appreciate its quality 
	more thoroughly the first time a user plays `Captain Ahab' with 
	your expansion cable and goes sprawling across the floor.

	The external chassis end of the 80-pin shielded cable is split into
	its 20-pin and 34-pin constituents using a `spare' PCB I bought
	just for that purpose (perhaps my additional parts quantities will
	make more sense after reading this section).  I used the PCB with
	another spare bracket and mounted it in my tower chassis.  Since
	I didn't have an official MDEM (DEM) chassis to inspect as a guide,
	I used a beeping continuity tester to insure that pin 1 from the 
	WD7000 controller corresponded to pin 1 of the edge connector for
	all of the disk cables.

                              +------------------------------------------
                              |                    
                              |                    +-------------+
                	      +---+   34 pin   +--+|             |
                	      |   |============|  ||  external   |
         80 pin external   /--|   |  (013046)  +--+|    EDSI     |
         ==================|  |PCB|                |   drive 1   |
	 (from DNxx00)     \--|   |   20 pin   +--+|             |
                	      |   |============|  ||   (add the  |
                	      +---+  (013047)  +--+| terminator!)|
                              |                    +-------------+
                              |                    
                              | (inside your hack-job MDEM)
                              +------------------------------------------

		Note: I am not sure about the cable numbers, they
		      were taken from figure 2-16 of the manual, and
		      I am asssuming they will work.

	The purpose of this section is to elighten you on the internals
	of the cabling.  If you are having trouble with these primitive 
	illustrations, look at the manual, figures 2-16 and 2-19.

	The two cables internal to the expansion chassis are available 
	from HP/Apollo, by using the same cables used internal to the
	DN chassis.  Upon close examination, I noticed two points:

		1)	They have HP/Apollo part numbers on them so you
			can order them from spare parts if you like.
			Unfortunately, I cannot open my node right now
			to confirm the part numbers for this article, but
			the ones I have written down are mentioned.

		2)	They are essentially no different than any other
			standard disk cable, except they are made of 
			`tubular' cable instead of `ribbon'. 

	I decided to make my own, but you can purchase them from any 
	computer supply store, too.  

		IMPORTANT:	some PCs use a twist in the 34 pin cable, 
				you must NOT have a twist in yours.

	You can probably find the edge and two-row header connectors
	from a cheap source and make your own cables from ribbon cable.
	This was my method, and since we have the items in large quantities
	in local stock, my cost was only a favor.

	================================================================
			the compiled parts list ... Part 3
	================================================================

	This will only cover the case of 1 external 760 MB drive.  Once
	you have added it, you should be able to figure out what parts
	will be needed to install a total of 3 additional drives
	per DN3k/4k.

	Now we get to the nitty gritty.  I obtained my parts from 3 diff-
	erent sources:

	  a)	HP/Apollo	misc brackets, PCB connector board,
				and 3 cables

	  b)	chassis		this houses the disk(s).  I managed to 
				'acquire' a standard tower chassis, which 
				is a story in itself.  All you are looking 
				for is something with an adequate power 
				supply and a full height drive bay.  The 
				external cable assembly is 10 feet long, 
				so you have plenty of room to hide it off 
				to the side, in case it is pasted with
				Motley Crue stickers or something.
					
	  c)	internal cables for your
		own external drive
		chassis:	I am referring to cables you need internal
				to your add-on chassis; see previous text
				for more on this subject.   These cables
				are PROBABLY HP/Apollo numbers 013046 and
				013047, but I didn't order them.  See fig
				2-16 of the manual for additional help.

	Items b) and c) make up the equivalent of the (M)DEM mentioned
	in the manual.  In order to properly connect the external EDSI
	cable to the disk in the DEM, you must purchase the following extra
	parts when you call HP's spare parts desk:

		 --.--	  1  	(013046 ??)	Internal round 34-pin
		 --.--	  1  	(013047 ??)	Internal round 20-pin
		140.00	  1  	012824		External PCB Board
		 15.00	  1  	012890		bracket
		   .10	  2  	014936-206	screws

	The extra quantities are ALREADY INCLUDED in the Apollo parts list
	that follow.  I mention them here in case you happen to wonder why
	my parts quantities don't correlate with those found in the manual,
	pages 1-4 and 1-5.

	----------------------------------------------------------------
		HP/Apollo Parts for 760 MB external add-on disk:
	----------------------------------------------------------------
	HP Spare Parts          800-227-8164 (they take Visa!)
	Tech Service Line	800-752-0900 (you must purchase support)
	----------------------------------------------------------------
		
	 Cost	Quan.	Apollo Part No	Description
	------	-----	--------------	--------------------------------
	140.00	  2 *	012824		External PCB Board
	500.00	  1 $	12837-001	80 pin external conn. cable
	 70.00	  1	012834		20 pin internal conn. cable
	 90.00	  1	012835		34 pin internal conn. cable
	 15.00	  2 *	012890		bracket
	   .10	  4 *	014936-206	screws
	------	-----	--------------	--------------------------------

	notes: * these items are double the normal quantity.  see
		 previous text.

	       $ this is a rather expensive item, see second source mentioned
		 later in this section.

	----------------------------------------------------------------
		Parts I made myself (or available from other vendors):
	----------------------------------------------------------------

      	  1	20 pin internal connector cable
			(to 20 pin edge card connector)
			possibly HP/Apollo part number (013047)

      	  1	34 pin internal connector cable
			(to 34 pin edge card connector)
			possibly HP/Apollo part number (013046)

	  1     tower PC chassis, to house the add-on drive(s).

	I found the ribbon cable and connectors in our stockroom.  You
	will find that these are basically the same as any other EDSI,
	MFM or RLL cables except Apollo didn't use ribbon.  This may be
	significant, but I was willing to take the chance.

	I cannot be sure that my 'hack' cables are of the correct impedance,
	etc., but since this EDSI configuration is terminated (at the add-on
	disk end), I don't believe I am inviting any serious problems.  It
	doesn't appear that the HP/Apollo version are all that special.

	----------------------------------------------------------------
	  Third party vendor for the expensive $500 cable (012837-001)
	----------------------------------------------------------------

	I intend to perform this expansion on more than just 1 node, so
	I felt it was worth the effort to try and get a cheaper cable.
	As I have mentioned throughout, you do so at your own risk.

	The vendor from which I obtained it actually supplies the connectors
	to HP/Apollo -- but there is one sticky point:

		HP/Apollo uses: Mercury  cable, Honda connectors
		        I used: Furukawa cable, Honda connectors
				--------

	The difference: we couldn't be sure.  The electrical characteristics
	appear to be very similar, but the Mercury surely has a tougher
	jacket.  Perhaps Apollo chooses the Mercury version because people 
	will inevitibly be stepping on your cable.  At any rate, I have 
	been using my Furukawa second source for 3 weeks now.

	If you wish to order Mercury cable, you must purchase 1000 feet (even
	though you only need 10).  With enough orders, my distributor could
	combine them to make the Mercury cable economically feasible.  Until
	then (and perhaps forever, since that would take quite an order),
	you will have to settle.  Don't be too scared, I personally don't
	feel this is too risky -- the bus IS terminated.

	This rather long discourse on cabling is include to alleviate my
	source from having to repeat this ad nauseum.  Here is how you
	may reach him:

			George Lawton
			Marathon Sales, Ltd.
			776 Waverly St.
			Framingham, MA  01701
				USA
			508-875-3566 telephone
			508-879-1179 FAX

	Approximate price: less than $100, much less in quantities 
			   greater than 10.

		cable assembly number:  AA-80R10FA-02

	I have notified him that I would to post his name in the Internet.
	This is in no way a commercial endorsement, simply a second source
	for a commercial product.

	================================================================
		Telling Domain/OS the disk is there ... Part 4
	================================================================

	This section assumes you are already familiar with the following
	tasks of system administration:

			booting a node 
			running CONFIG (EX CONFIG at MD prompt '>')
			running INVOL  (EX INVOL  at MD prompt '>')
			running SAX    (after Domain/OS boot)

	When you power up your node, you should notice that the disk
	test finds the second disk.  If not, better power down and check
	the cable connections again.  The power-up diagnostics found 
	it even before I ran CONFIG (set the maintainence switch, SW2,
	to its `bottom' position to prevent automatic boot of the node.

	Did you remember to remove the terminators on the internal disk?
	See step 7 on page 2-10 of the manual.

	Run CONFIG to tell Domain/OS you have added the disk.

	You will need to run INVOL to low-level format your disk.  Refer
	to the disk with the following mnemonics:

			w0:0	internal (existing) disk
			w0:1	external disk 1, on same controller 
				as the internal disk.

			w1:0	drive 0 on second (optional) controller
			w1:1	drive 1 on second (optional) controller

	I will make no attempt to warn you of all of the possible nasty
	things you can do should you INVOL the internal disk instead of
	the new one.  You were supposed to back that up before you con-
	nected the first cable.

	Once INVOL'd, you should be able to mount the disk with the
	Aegis command:

			/com/mtvol w0:1 /extra_volume_1

	Try an LVOLFS  (/com/lvolfs) to see if it shows up.  If you have
	trouble with this, you might be in for a long night.  Mine worked
	the first time, so I cannot help you here.  I told INVOL to part-
	tition my 780 into 2 approximately 300 MB partitions, so I have to
	add the second invocation:

			/com/mtvol w0:1 2 /extra_volume_2

	If you mounted the volume with the Aegis 'mtvol', do not forget
	to unmount it with 'umtvol' before you attempt any of the Unix
	versions of these commands.

	If you are running a Unix SYSTYPE under Domain/OS, you must now
	perform some additional commands to make the drive's '/dev' device
	mnemonic.  This is beyond the scope of this hardware lesson, but
	if you have the HP/Apollo support script '/etc/mkdsk', it is rather
	simplified.  I obtained it from the Mentor Customer support group,
	and its purpose is to make the disk device:

			 device		 relates to logical disk
			---------	----------------------------
			/dev/wn1a	(logical partition 1, w0:1)
			/dev/wn1b	(logical partition 2, w0:1)

	   p.s.: in my version of 'mkdsk' (dataed 89/08/21), there is 
		 a typographical error on or about line 40:

	          is:  	if [ $4 -lt 1 -o $3 -gt 15 ] ; then
	   should be: 	if [ $4 -lt 1 -o $4 -gt 15 ] ; then
					  ^
					  should be '4'

	Once you run '/etc/mkdsk' to make the device number (which simply
	calls the Unix utility '/etc/mknode' with the correct arguments),
	the device /dev/wn1_ will exist.  Then you can:

			mkdir                   /extra_volume_1
			/etc/mount  /dev/wn1a	/extra_volume_1

			mkdir                   /extra_volume_2
			/etc/mount  /dev/wn1b	/extra_volume_2

	This will allow you to use the BSD /etc/mount to easily mount the
	disk as a 'BSD' type device (run /etc/mount with no arguments to
	see what kind you get.  If you used /com/mtvol it will be of type 
	'Aegis'.  I wasn't sure what the implications of this were (probably
	minor, since Domain takes care of the filing systems anyway).

	Don't foget to update /etc/fstab with your new volumes or you
	will need to SALVOL it each time you reboot (ouch!).  It looks 
	something like this:

			/dev/wn1a /extra_volume_1 4.3 rw 0 0 0
			/dev/wn1b /extra_volume_2 4.3 rw 0 0 0

	Most of all -- good luck!  I hope this is enough to get you started.

	================================================================
	              Summary and Disclaimer ... Part 5
	================================================================

	After spending small fortunes on hardware and software, I found 
	that management was rather unwilling to provide me with enough 
	disk space to properly manage an efficient and quality EDA 
	environment.  Since my primary responsibily is engineering rather 
	than systems administration, I felt it was critical to provide 
	the users community with enough disk space that I wouldn't have 
	to run disk sizers every night to nail users that kept more than 
	two copies of their designs.

	I hope that this long dissertation will provide the knowledge 
	for the general public to make intelligent choices.  Make no mis-
	take, cobbling this together will take a lot of time, and you 
	will find it difficult to convey your sense of urgency upon either
	your boss or your customer service representative should it not
	appear to be working.  Your best bet, as always, is:
	
		Don't panic
		Don't make assumptions (check continuity of cables)
		Don't be afraid to find a `buddy' to help you; they
			often can find your silly mistakes much more
			quickly than you will alone.
		Don't do this at 1:00 am like I did.

	----------------------------------------------------------------
	Disclaimer:
	----------------------------------------------------------------
	I am not affiliated in any way with:

			Marathon Sales, Ltd.
			HP/Apollo (Hewlett Packard)
			Mentor Graphics, Inc.
			IBM (International Business Machines
			AT&T (American Telephone and Telegraph)

	I have freely used Trademarks of these respective companies 
	throughout this article, so be sure to contact them before you
	attempt to name a perfume after one of them.

	----------------------------------------------------------------

	My views and suggestions are my own, and not those of Racal 
	InterLan, Inc. (all they know is that I saved them mucho $$).

((((((((((((((((((((((((((((((((((|))))))))))))))))))))))))))))))))))))))))
(( Sr Hardware Engineer       ))    ((  Jeff Koehler                     ))
(( Racal InterLan, Inc.       ))    ((  [email-masked]                 ))
(( Boxboro, MA  508-263-9929  ))    ((  imagine code with this many '('s!))
((((((((((((((((((((((((((((((((((|))))))))))))))))))))))))))))))))))))))))