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Date:      Mon, 7 Oct 96 15:07:35 CDT
From: (Steve Bartling)
To: (Steve Bartling)
Cc:,, (Carl Dietz)
Subject:   Re: Irwin ( exabyte 8200 ) and Freebsd 2.1.5 RESOLVED
Message-ID:  <>
In-Reply-To: <>; from "Steve Bartling" at Oct 3, 96 1:17 pm

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For those of you with the 1742A or other aging Adaptec products ...

I spent 1 week trying to determine why an Exabyte 8mm tape
drive would not work under Freebsd 2.1.5 or Windows95 with an
Adaptec 1742A.

Symptoms ... :

Freebsd 2.1.5 would properly recognize the tape drive upon
boot and could read tapes, but not write tapes. Attempting to
write the tape would cause SCSI bus lockup ( a hard reset is required ).

Windows95 could recognize the tape drive with various backup
programs ( Arcada, etc ). However, attempts to write the drive would
lock up the SCSI bus. Unlike Freebsd however, the drivers under
windows 95 could recognize the bus problem and would reset the
SCSI bus. I would really like to know how this is done.

Solutions :

The Adaptec 1742A bios/microcode was not up to date. My card
had the following designations on the bios/microcode eproms :

450113-00 D

450216-00 A

Downloading the latest bios/microcode from Adaptec's web page fixed
the SCSI bus hang condition. There are two firmware updates on their
web page. The firmware file named 174XA.EXE has a corrupted bios
file. Do NOT use this firmware. The firmware file named 174XAS.EXE has
the more recent bios/microcode and is not corrupted. Please make sure
that you use the same EPROM types/speed as the original board uses.
Please note that the bios revision number that is displayed at
boot time does not change ( maybe microcode is the only thing 
changed ? ). I do not know what was wrong with the old bios/microcode
as Adaptec's on line documentation on the firmware upgrades was
nil/non-existent and I never heard back from their technical support.

Also, the switch settings on the MX controller card for the Exabyte
tape drive need to be tweaked. The card was set for fixed
block size mode. The best setting is variable block mode. The parity
checking was disabled ... this needs to be enabled if the rest of
your scsi peripherals have parity checking enabled ( like mine ).
Remember, parity must be ON for all devices, or OFF for all devices
on the same scsi bus. Another useful thing to change is the memory
check during scsi bus reset ( or power-on reset ). It takes about 
60 - 70 seconds to complete this test and this will delay your
DOS/windows95/unix boot until the test is completed. If you change
this setting to disable this test, boot times are greatly enhanced.
Note: reaching these switches is a pain in the butt.

For the switch settings, please see the Exabyte web page at 

I want to thank those of you who responded. I especially want to
thank everyone at Exabyte for the following reasons :

1) Exabyte actually supports old products. Their web page is loaded
   with information about older out of production stuff. They
   even provide invaluable DOS based tape drive test programs. 
   Every firmware revision is thoroughly documented so that the
   history is evident and you can evaluate if you need to upgrade
   your current firmware.

   Most tape drive vendors only have info on their current products
   in their web pages.

   Believe it or not, I actually decided to purchase an Exabyte
   8mm drive instead of other vendors 4mm drives due to their 
   support for old products. After spending 3 weeks browsing
   web sites, BBS sites, old product reviews, etc ... I decided
   on Exabyte.

2) Exabyte actually responded to my email about the problems I was
   having. This is in stark contrast to Seagate and Adaptec from whom
   I never heard anything. In addition, the support personnel at
   Exabyte are well trained and knowledgeable. Many thanks to
   Lance Blumberg at Exabyte !!!.

Thanks to everyone who responded ...

- Steve Bartling

P.S. My original message is appended below.

> Howdy,
> According to the Freebsd 2.1.5 documents, the st scsi tape driver
> has built in support for the Exabyte 8200. 
> I have attempted to install this drive on SCSI ID 5. (Side note,
> the firmware revision is the generic 2618.)
> I have used the "expert" DOS software package that I downloaded
> from to test the drive under DOS. Other than
> a tendancy to report fairly high Rewrt and ECC percentages on
> the first couple of megabytes written, the drive passed all
> of the tests that this software provides. The Rewrt and ECC
> percentages will drop as you write/read more data from
> the drive. If you write/read enough data, the percentages 
> average out to acceptable values. Is this typical behavior ?
> Oh well, I digress ...
> My real problem is with Freebsd 2.1.5.
> I have two tape drives installed. An Archive 2150s is present
> on SCSI ID 4. The 8200 is installed on ID 5.
> I created the proper devices in /dev using the "/dev/MAKEDEV st1"
> command. All of the proper devices were created.
> I rebooted just to make sure everything was clean and verified
> that Freebsd properly probed/detected the 8200 and attached it
> to the st1 interface. The Archive 2150s was also properly identified
> and was attached to st0.
> Now for the problem ...
> The Archive 2150s works fine. When I attempt to "tar -cvf /dev/rst1"
> the entire SCSI bus hangs, requiring a machine boot to clear the
> bus. I cannot use the st or the mt utilities to display status or
> set modes. When I attempt to do so, I get "Invalid Input/Output Error".
> Again, I can access the 2150s just fine. Hardware does not seem to be
> at fault since both drives are happy under DOS.
> Any clues ?
> - Steve Bartling
> email:

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