From:	CRDGW2::CRDGW2::MRGATE::"SMTP::CRVAX.SRI.COM::RELAY-INFO-VAX"  2-NOV-1990 17:37:21.26
To:	MRGATE::"ARISIA::EVERHART"
CC:	
Subj:	Problems with V5.4 Unibus drivers on SMP boxes

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Date: 2 Nov 90 14:01 EST
From: TOM_BODOH_X6830@VAXA.CR.USGS.GOV
To: info-vax@crvax.sri.com
Subject: Problems with V5.4 Unibus drivers on SMP boxes
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Hello netlanders,

	Last week I posted about a rumour regarding VMS V5.4 driver
changes breaking third-party SCSI boards.  A reply said that this was
only a problem on the 3100 series.  I cannot comment on that yet...but...

	Well, I just upgraded our 8350 from V4.7 to V5.4 and as soon as
we began using both tape drives at once, the system machine checked.  These
tape drives connect to the Unibus via a foreign tape controller and use the
DEC TSDRIVER.  Colorado software support was quick to label this a hardware
problem.  At the suggestion of the producer of our third party tape controller,
we reloaded the TSDRIVER from VMS V5.3-1 and this works.

	DEC's response to this was that use of the TSDRIVER on a Unibus adapter
SMP machine is not a supported configuration and therefore it need not be SMP
hardy as far as they were concerned.

	Later, a foreign driver which we use with a DEC DR11W started causing
machine checks with a nearly identical stack footprint as the TSDRIVER.  I
rebuilt the foreign driver on a VMS V5.3-1 system, moved it back to the 8350
and rebooted.  The crashing now seems to have stopped.   Hmmm... seems to me
that DEC changed SOMETHING in V5.4 which causes some drivers built under V5.4
to break on SMP Unibus systems, while V5.3 versions of the drivers still work.

	After discussing all of this with Colorado software support, they
seemed happy that we resolved it.  I'm still looking into the actual cause
as they don't seem at all interested.  We plan to migrate the tape drives and
the DR11W connected device to the BI, which should help us avoid any future
problems.  I'm sending this message as a note of caution for those sites
running similar configurations.  Bye...

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Tom Bodoh - Sr. systems software engineer				       +
+ EROS Data Center, Sioux Falls, SD, USA	57198			       +
+ (605) 594-6830	FTS 753-7830	 SPAN; EROSA::BODOH (7357::BODOH)      +
+ Internet; BODOH@VAXA.CR.USGS.GOV (192.41.204.12)			       +
+	"Welcome back my friends to the show that never ends!" EL&P	       +
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