8mm off a VME/SCSI adaptor

[John Cornelius]

In article <798 at brazos.Rice.edu> you write:
>X-Sun-Spots-Digest: Volume 8, Issue 96, message 1 of 15
>
>In article <569 at brazos.Rice.edu> abrams at bnlux0.bnl.gov (The Ancient Programmer) writes:
>>X-Sun-Spots-Digest: Volume 8, Issue 86, message 8 of 18
>>
>>I'm trying to get an Exabyte 8mm tape unit for my Sun 3/280 with a VME
>>buss, running SUNOS 4.0.1, and I would rather not have to install a
>>"foreign" driver in the kernel.  Salesmen, who all lie, have been giving
>>me conflicting information.
>>
>
>Foreign drivers have a lot to offer over the Sun scsi drivers.  For one
>thing, many work.  This definitely cannot be said about the Sun drivers.
>Just try using a SCSI disk with the  SUN-SCSI driver.  Chances are it
>won't work.  And as any regular readers of this newsgroup know, the
>Exabyte has problems running under 4.0.1. (Unless you remove the st patch
>or something, but the patch must have been put there for *some* reason)

I suppose it depends on who you get it from but generally speaking I
believe that you are in error.  There is no problem running an Exabyte
under 4.0.1 provided you have a reasonably recent release of the firmware.
Most exabyte problems I am aware of result from either old firmware,
multiple terminations on the SCSI, no termination on the SCSI, use of
unmatched SCSI cables, use of the wrong driver on the right SCSI
controller, or using the Sun-2 SCSI controller (sc) to drive the SCSI.  I
have seen a fairly small number of Exabytes that were actually broken but
it is the case that Exabytes work on Sun-3 and Sun-4 systems under
SunOS-4.0 and above without modification to either the hardware, firmware,
or the software.  You can even boot off of it if it's set up as st0.

There is only one piece of software that I have seen that is even a little
bit useful that is not standard Sun software and that is Peter Beren's
mdump program.  While I don't feel a need to use it I know that quite a
few customers like it.  As for drivers, why put yourself at the mercy of a
tapedrive supplier when you want to upgrade to a new operating system
revision?  That's just inviting problems as far as I can tell.

Also, while I am not a salesman and hold the generic saleman in fairly low
regard I object to the notion that salesmen lie, they generally do not do
so, at least not intentionally.  What they DO do, is tell you more than
they actually know.  There is a difference.

>I realize that many people are dealing with these shortcomings because
>they already have the SUN-SCSI combination.  But for those who have a VME
>bus I would recommend considering that foreign driver.  They often cost
>less than official Sun alternatives and support a much wider range of
>hardware.  And with the Sun product, you will be purchasing several "known
>bugs" and "Sorry, the Exabyte is not a supported product".

Well, there's support and there's support.  Take a look at
/usr/sys/sundev/streg.h and you'll see the Exabyte parameters and support.
While the "support" has been deleted from Sparcstation 1 distributions I
understand that it is an "option" and I expect to see it back in 4.1.

>I'm sitting here using a system with our foreign :-) Host adapter and
>driver.  Attached I have a 8mm tape drive, a 4mm tape drive, a Magneto
>Optical disk, a Maxtor XT-8760S, and a Wren V.  All work like a charm.
>None require changes to the driver.  None involved Sun support. :-))))

I too run all of these devices on a standard Sun SCSI (si0) with no
drivers other than those supplied with the operating system.  While I
don't mind you spending your money on needless endeavors (my company sells
this stuff) I'd much rather you spent it on something you need.

John Cornelius			jc%andataco.uucp at ucsd.edu
Andataco			(800)334-9191
9550 Waples
San Diego, CA 92121