[u3b.tech] 3B2 Hard Drives

eric@sactoh0.SAC.CA.US (Eric J. Nihill) (11/21/90)

  I would like to thank Greg Woods for giving me some information
regarding Maxtor drives. His information did help in formatting
the drive.

  There does seem to be a hardware configuration problem between
Maxtor XT series drives and 3B2/310s and 400s. The problem seems
to be with the controller on the 3B2 being able to initialize the
disk. Although you may be able to formatt the disk with idtools,
if the system needs to initialize the disk during normal operation
or to write to the defect map, it will fail. This problem was 
common on several Maxtor XT series drives tried on both 310s and
on 400s. I have formatted Priams, Miniscribe and CDC drives with
no trouble using idtools.

During the course of a day, it was commom to hear the drive let out
a electronic sounding howl, freeze the system for about 1/10 of
a second, then march on. The disk stayed up and running under
full load for about 2 days. At that point, it tried to write a
bad block it found to the defect map, was unable to, and went
into a loop trying.

 Upon rebooting of the system, the the drive configuration table
was no longer there. The drive just sat there and let out an
electronic sounding static noise, with the drive access LED on.
 
 There must be a modification than can be made to the XT series
drives to get them to fly, either with pin jumpers or on the
drive board trace, but I am lost for ideas.

					Eric

-- 
     Some do, some don't.           |       eric@sactoh0.SAC.CA.US
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flynn@clotho.acm.rpi.edu (Kevin Lincoln Flynn) (11/25/90)

We have a problem.  We've a 3B2/400 with two 72MB drives (CDC Wrens, unless I
misremember), and we cannot format the disks with idtools.  We say 'formhard'
and enter the defect table, and then spits 'cannot read physical info' at us
and quits.  Help!  We need this machine....  any information anyone has would
be greatly appreciated.  Schemes which rely on running DOS boxes, 3B2/300s,
/400s or a 3B15 can be implemented.

Also, if Steve Friedl still reads this group, please drop me a line....

Again, help will be greatly appreciated.  Thanks in advance!!

----
Kevin Lincoln Flynn    flynn@acm.rpi.edu, userfwvl@mts.rpi.edu
494 Madison Avenue     H (518) 432-0812  W (518) 447-8561
Albany, New York, USA  12208
...Argue for your limitations, and sure enough they're yours.

flynn@clotho.acm.rpi.edu (Kevin Lincoln Flynn) (11/26/90)

Whoops...  forgot to mention that information on the proper settings of drive
ID jumpers and terminating resistor packs in a dual-drive configuration would
be vastly appreciated.  Thanks!

----
Kevin Lincoln Flynn    flynn@acm.rpi.edu, userfwvl@mts.rpi.edu
494 Madison Avenue     H (518) 432-0812  W (518) 447-8561
Albany, New York, USA  12208
...Argue for your limitations, and sure enough they're yours.

woods@eci386.uucp (Greg A. Woods) (11/26/90)

In article <4346@sactoh0.SAC.CA.US> eric@sactoh0.SAC.CA.US (Eric J. Nihill) writes:
>[ stuff about Maxtors vs. 3b2's ]

I tried sending mail to Eric about this, but it was bouncing.  Perhaps
he will see it if I post it here... :-)

[ On Tue Nov 20 12:37 (Re: "Maxtor Drives"), Eric wrote: ]
>   It seems that there is a hardware configuration problem
> between a 3B2 and a XT series Maxtor. This problem of being
> able to read the defect table one minute and not the next
> seems to be common with several XT series Maxtors on several
> 3B2's. 

Nope, it's a driver bug.

>   Are there any options on the drive that should be set to
> make it work with the 3B2? Jumper pins? Cut traces??

Yup, there's a patch (sorry I don't have the actual patch, since my
machine is down and out [lightning strike], but you should be able to
get the fix from AT&T).

I found this patch did not fully correct the problem, but only reduce
the hangs to a very short (1-5 secs.) time.  The drive(s) will always
re-cal. though, and yes if you get a bad-block when this happens, it
can start thrashing.

The only real fix would be to re-write the id interrupt handler, and
or speed up the machine.  (The patch is for 3.1v2.)

I've used a pair of Maxtor-1140's on my 3b2 after installing this
patch with no other problems at all.  This is with the drives
formatted out beyond their capacity (i.e. to 1024 cylinders).  I've
only had one or two bad blocks form on a drive during an operating
period of about 1 year, and the bad-block software took good care of
mapping it out.

I have had one second-hand 1140 go bad, and anther re-built model
require a second re-construction because the shippers appeared to have
used it as a football....
-- 
						Greg A. Woods

woods@{eci386,gate,robohack,ontmoh,tmsoft}.UUCP		ECI and UniForum Canada
+1-416-443-1734 [h]  +1-416-595-5425 [w]    VE3TCP	Toronto, Ontario CANADA

pag@tcsc3b2.tcsc.com (Philip A. Gross) (11/28/90)

flynn@clotho.acm.rpi.edu (Kevin Lincoln Flynn) writes:

>We have a problem.  We've a 3B2/400 with two 72MB drives (CDC Wrens, unless I
>misremember), and we cannot format the disks with idtools.  We say 'formhard'
>and enter the defect table, and then spits 'cannot read physical info' at us
>and quits.  Help!  We need this machine....  any information anyone has would
>be greatly appreciated.  Schemes which rely on running DOS boxes, 3B2/300s,
>/400s or a 3B15 can be implemented.

The first thing to check out here is to make sure that the drives are
addressed properly and that the resistor pack is properly installed.  The
resistor pack must be installed on the LAST drive in the chain.  You will
find a socket at the rear of each drive that can accomodate the resistor
pack.  Next to the socket is a set of Burge (sp?) jumpers.  As I recall,
the jumper farthest from the resistor pack will address the drive as 0.
Typically, the first drive in the chain is drive 0 and the second/last is
addressed as drive 1.

Next, when using idtools, I would suggest that you first select the option
for entering the defect map of the drive(s) only.  Then, if this succeeds,
proceed to the formhard option.  The formhard option should then present
the defect map information that you previously entered.  It is also
important to make sure that you describe the drive properly.  The description
of a CDC Wren II is as follows:

		Drive ID: 5
		512 bytes/sector
		 18 sectors/track
		  9 tracks/cylinder
		925 cylinders
		923 user accessible cylinders

Hope this is of some assistance.
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Philip A. Gross       The Computer Solution Co., Inc.       Voice: 804-794-3491
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