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From: ejy@cbnewsi.att.com (eugene.yurek)
Newsgroups: comp.periphs.scsi
Subject: Re: Problems with Adaptec 1542B and Seagate ST-251N
Message-ID: <1990Nov15.170707.17838@cbnewsi.att.com>
Date: 15 Nov 90 17:07:07 GMT
References: <46492@sequent.UUCP>
Distribution: na
Organization: AT&T Bell Laboratories
Lines: 69

From article <46492@sequent.UUCP>, by norsk@sequent.uucp (Doug Thompson):
> After considable effort to solve this problem the old fashioned
> way (calling one vendor, then the other, each pointing the finger
> at the other) and understanding the problems of SCSI components
> working together, I am asking for help from the group.
> 
> Situation:
> 	I purchased a ST251N and ST01 some 18 months ago. It worked
> 	just fine. Then I recently purchased an AHA-1542B and a problem
> 	shows up. The drive fails the VERIFY cmd (op=2Fh) in that
> 	the drive light stays on and the onboard (and the device
> 	driver from adaptec wo/BIOS on) times out indicating the
> 	VERIFY cmd failed. The light remains on until reset.
> 	This occurs trying to utilize both my FXPREP partitioning
> 	prgram from Tandon and Adaptec's AFDISK.
> 
> 	Now this drive FORMATS fine, with differing interleaves,
> 	reads and writes (with my own built driver to the
> 	AHA-154xx) and to my own driver under an older XENIX
> 	that didn't support the adaptec board.
> 
> 	Now, Seagate says they will  'repair' the board for $180 which
> 	is just a board replacement, etc, and that their drives
> 	support VERIFY. Adaptec says "Sorry to hear about that"
> 	and my distributors service line (Wyle Labs in Orange county)
> 	says, "It should work".
> 
> 	I am not flaming any here, just telling facts.
> 
> Question:
> 	Has anyone else had this problem or heard of it?
> 	Any suggestions?
> 	Any other data points I could use in determining the problem?
> 
> 	I don't wish to not use the drive. Its a good 40M drive and
> 	it will be a little while before I can get some bigger
> 	SCSI drives.
> 
> thanks in advance.
> 
> Douglas Thompson		UUCP: ..{tektronix,ogicse,uunet}!sequent!norsk
> 				Internet:	norsk@sequent.com
> "The scientist builds to learn; the engineer learns in order to build."  
> Fred Brooks

I was told by an Applications Engineer at Adaptek (I believe) that there was
a problem with the OLD Seagate SCSI drives relating to the VERIFY command. 
It seems that Seagate's interpretation of how the VERIFY command should
work is to verify the ENTIRE surface, when in fact it should only verify
the current track.  The Adaptek Apps Engineer said that the drive
would work fine once you get it verified, but that the entire drive would
be verified the number of times the drive has tracks (this could be
days).

The solution I took was to plug-in an ST01 and go through the FORMAT/VERIFY
with this controller, and then power-down the system and replace the ST01
with the Adaptek.  This works fine because all of the low-level format/
verify/access hardware are on the drive, so there is no possibility of
an incompatible format (providing you want 512 byte logical blocks).

The apps engineer couldn't give me an exact date, but said that Seagate
fixed this "problem" about 1 year ago.  Since your drive is older than
this, there is a very high probability you've been bitten by this problem.


--
Eugene J. Yurek				Internet: ejy@honasa.att.com
AT&T Bell Laboratories			    UUCP: ...!att!honasa!ejy
Holmdel, NJ				   Voice: (201) 949-3753