Submission for comp-unix-microport

[UNIX-UNIX Cp]

Path: tolerant!voder!pyramid!oliveb!amdahl!pacbell!belltec!dar
From: dar at belltec.UUCP (Dimitri Rotow)
Newsgroups: comp.periphs,comp.unix.microport
Subject: Re: tape streamers question
Summary: comments on BTI pals
Message-ID: <321 at belltec.UUCP>
Date: 2 Jan 89 22:33:02 GMT
References: <1516 at bebux.UUCP> <895 at starfish.Convergent.COM> <314 at belltec.UUCP> <271 at dcs.UUCP>
Organization: Bell Technologies, Fremont, CA
Lines: 39

In article <271 at dcs.UUCP>, wnp at dcs.UUCP (Wolf N. Paul) writes:
> Would you care to comment on the REASON for the change of PALS on the Bell Tech-
> supplied EV-811-B controller, which in effect makes the use of Bell Tech's
> System V/AT tape driver impossible with a non-Bell Tech EV-811-B?
> 

You bet!

Bell started shipping tape drives at a time when there were 15 or 20 different
implementations of QIC-36 tape drives.  The initial PAL was used simply for
version control and host board identification.  We keep using it because we
read Usenet and don't want to get involved supporting other people's tape
controllers and tape hardware.  Sure, in theory you can whack together just
about any QIC-36/QIC-02 generic controller and tape mechanism and expect it
to go, but (as readers of this and the comp.unix.xenix group know) it just
doesn't work that way in practise.  Our own line of integrated controllers,
tapes and software provides special value which we intend to keep selling 
for our benefit.

As it so happens, we *do* sell a commodity tape interface that works on almost
anybody's controller/driver pair ... that's the "qt" (for Qic Tape) streamer
driver that's part of our UNIX System V/386 Release 3.2 distribution.  You 
get that driver free as part of the standard release.  If you buy a Bell Tech
streamer tape, you get our tape stuff free as well.  The Bell tape software 
streams a heck of a lot better than the AT&T stuff.  One reason is that it 
is precisely integrated with a specific family of controllers and tape 
mechanisms.  You pays your money and you takes your choice.

Note, by the way, that your posting makes an inaccurate assumption in that
you imply that there is only one EV-811-B controller, when in fact their
are very many different revs of that controller boards that ship under
the very same or similar part numbers.  This is not a criticism
of the EV product, just a note on the hidden dimension of version skew.
One of the ways we've been forced into dealing with version skew is to 
start fabbing our own QIC-02 series tape controllers.  This assures us
that our customers will not be hurt by hardware version skew.  Wangtek, 
by the way, is also fabbing their own EV series controllers as well.

- dimitri rotow