SCSI 9-track tape drives

[Loren Buck Buchanan]

Hi,

Here is my followup to a few postings I made some time ago about 9-track tape
drives.  Because of various restrictions, government procurement rules, etc.
we now have two Pertec FS-2001-2 (SCSI interface and 1Meg cache).  After
spending a couple weeks trying to get either dd or my own custom software
to read tapes we get from our customer, I started over from scratch using
the low level SCSI device driver (cd /usr/people/4Dgifts/examples/devices;
more README).

I now am able to read the tapes, but the code is not pretty, nor is it
transportable.  What I don't understand now, after going through this
exercise, is why dd and my earlier custom software does not work with the
Pertec, as I have followed the SCSI standard (X3.131-1986), and there was
no funny vendor specific stuff that had to be done to get it to work.  (To
optimize through put, well that is a different story).  What I would hope
Silicon Graphics (and other vendors as well) is to provide generic drivers
for unsupported devices (set vendor specific bits to zero) and hope for
the best.  In addition to this, I would like to see is configurable drivers
(i.e., via /usr/sysgen/master.d/scsi) to provide access to the bits that
would allow for optimization.

Since we got our tape drive, it seems as though Cipher has come out with
a new model, the 995.  It is physically small enough to fit in the space
allotted (10" or less of rack face).  I would assume that it is upward
compatible with the 990 which does work with IRISes.  Another project in
the building just bought one.  It was a bit more expensive than the Pertec, 
but they had heard about my problems, and decided not to buy Pertec.  Guess
what does not work with the Sun or HP workstations?  Yep, the Cipher is
not yet working for that other project (mayby I can work a trade ;-).  I
have gotten from the Pertec vendor a device driver for the SPARCstation.

Oh well, I guess thats life in system integrators lane (SGI is providing
me job security ;-) ;-) ;-).

B Cing U

Buck

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