Technology and Trends
 USENET Archives
  
Path: gmd.de!Germany.EU.net!netmbx.de!zrz.TU-Berlin.DE!zib-berlin.de!
xlink.net!howland.reston.ans.net!vixen.cso.uiuc.edu!gateway
From: do...@BSDI.COM (Donn Seeley)
Newsgroups: info.bsdi.users
Subject: Adaptec AHA-2742/2842 news
Date: 20 Jan 94 19:44:41 GMT
Organization: University of Illinois at Urbana
Lines: 72
Approved: Use...@ux1.cso.uiuc.edu
Message-ID: <9401201944.AA06391@BSDI.COM>
NNTP-Posting-Host: ux1.cso.uiuc.edu
Originator: dae...@ux1.cso.uiuc.edu

[My apologies for the mangled headers in the previous messages...
I guess I'm a bit slow to wake up this morning!]

Adaptec has finally provided BSDI with an official response to our
request for programming information on their new SCSI parts.  We
received a document titled 'Programming Directly to AIC-7770-Based
Adaptec Products: What Developers Need to Know.'  The document
mentions that the AHA-174x products will be phased out by June '94,
and that new products will be based on the AIC-7770 chip.  It then
goes on to discuss the AIC-7770 interface.

Basically, the AIC-7770 is a 'RISC-Based EISA-to-Fast-SCSI host
adapter on a chip.'  It is programmable, and in general is only
useful if it is running an Adaptec-supplied microcode program.
The actual firmware, and the interface to the firmware, will be
provided to developers only under non-disclosure.  Adaptec will
supply source code for downloading the AIC-7770 and driving the
interface; this source code is called the HIM or 'Hardware Interface
Module'.  The HIM source code cannot be redistributed, and developers
may not modify the source code except to combine it with their
software.  Adaptec retains title to the source and object code and
grants permission to use it on a 1-year license, which is automatically
renewed unless unstated problems arise.  All critical documentation
about the AIC-7770 interface is 'Adaptec confidential' and is
covered by non-disclosure.  Adaptec provides an 'HIM Developer
Request Form' which requires you to describe the nature of your
need for the documentation and firmware, and state who your important
customers are and how many units you will ship.  If you send in
the form and Adaptec accepts it, you get a packet in the mail which
has a 'break-the-seal' envelope with a license agreement printed
on the outside.  (Hope I have summarized this correctly...)

Given this information from Adaptec, I see three approaches to
developing drivers for the AHA-2742/2842VL adapters.  (1) BSDI
could try to write its own HIM equivalent, using only freely
available documentation such as the AIC-7770 Data Book.  The on-chip
microcode store is fairly small, holding 448 RISC instructions;
this might mean that the microcode normally holds a library of
channel programs which manipulate the SCSI state machine for
particular operations.  To write microcode, we would have to
duplicate Adaptec's development efforts in the dark, starting by
writing an AIC-7770 micro-assembler, coming up with a set of
programs, and going through a lot of work to debug the programs.
The resulting driver would be redistributable as source code,
however.  Just to further discourage folks who might want to try
this, the Adaptec material mentions that Rev E of the AIC-7770 will
change the HIM, although old versions of the HIM will still work
without taking advantage of improved performance.  (2) We could
sign the non-disclosure and write a host adapter driver which does
the work of the HIM without actually including it.  The resulting
driver might or might not be redistributable in source code form,
depending on details of Adaptec's license.  If it would indeed be
redistributable, then this alternative would be much faster than
(1).  Keeping up to date with Adaptec's changes could still be a
pain, however.  (3) BSDI can sign the non-disclosure and not
distribute source for the 2742/2842 host adapter driver.  We would
still ship source code for machine-independent drivers and other
host adapter drivers, just not for new Adaptec products.  This
sucks, but it's better than nothing, and would get a driver to our
customers faster than any other alternative.  (4) Stop supporting
new Adaptec products.  I think customers will find this unacceptable,
although I'm open to comments.

As someone who believes in shipping source code for everything for
a reasonable price, I find Adaptec's attitude offensive and
short-sighted, but there's probably nothing BSDI can do to change
it.  If you have comments about any of the alternatives I've listed,
send them to me and I will summarize.

I really, really hate object-only drivers,

Donn

Path: gmd.de!Germany.EU.net!EU.net!ub4b!news.cs.kuleuven.ac.be!blekul11!
news.ysu.edu!usenet.ins.cwru.edu!howland.reston.ans.net!vixen.cso.uiuc.edu!
gateway
From: MDIC...@csi.compuserve.com
Newsgroups: info.bsdi.users
Subject: Re: Adaptec AHA-2742/2842 news
Date: 21 Jan 94 16:28:30 GMT
Organization: University of Illinois at Urbana
Lines: 22
Approved: Use...@ux1.cso.uiuc.edu
Message-ID: <CSI_5991-5377@CompuServe.COM>
NNTP-Posting-Host: ux1.cso.uiuc.edu
Originator: dae...@ux1.cso.uiuc.edu

Donn,

  There are certainly other high performance cards available.  We've been
using the Buslogic 747s for a while and I'd planned on doing an enhanced
mode driver based on the current eaha code and the copious drive doco
I got from Buslogic for free after a phone call.  Personally I have a
hard time rewarding vendors who treat driver doco as proprietary.  We
do a fair amount of custom hardware here at CompuServe and the ability
to do occasional custom driver work is important to us.

  I think the real goal is to have a high performance, supported SCSI
card with drivers available.  Both the Buslogic cards and also
competing cards from Ultrastor come to mind.  Having sources is
important.  I may want to look at doing some target mode code in the
future an an object only driver is no help at all.

  Just my 2 cents worth...


Mike Dickson
CompuServe, Incorporated

Path: gmd.de!Germany.EU.net!EU.net!howland.reston.ans.net!vixen.cso.uiuc.edu!
gateway
From: bd...@gag.com (Bdale Garbee)
Newsgroups: info.bsdi.users
Subject: Re: Adaptec AHA-2742/2842 news
Date: 21 Jan 94 23:47:31 GMT
Organization: University of Illinois at Urbana
Lines: 24
Approved: Use...@ux1.cso.uiuc.edu
Message-ID: <199401212347.QAA12389@winfree.gag.com>
NNTP-Posting-Host: ux1.cso.uiuc.edu
Originator: dae...@ux1.cso.uiuc.edu

In article <CSI_59...@CompuServe.COM> you wrote:
: There are certainly other high performance cards available.  We've been
: using the Buslogic 747s for a while...

Anyone have a list of Buslogic's products and what they do?  I've been an
Adaptec user (3 1542B's and a 1740A at home) for a couple of years, but will
gladly switch to an alternative if driver information is more readily 
available.

A phone number or a pointer to a source of information would be fine.  I've
seen the cards in ads from time to time, but while I can rattle off Adaptec
model numbers and what they do, I have no equivalent in my head for Buslogic.

: I think the real goal is to have a high performance, supported SCSI
: card with drivers available.

Yes.  I'd really enjoy having fast-wide-differential support, but that's less
important to me than having good ISA/EISA interfaces to 8-bit single-ended
hardware... with driver source.  So far, the only thing I've been willing to
run without complete source on my BSDI system(s) are Xircom PE-2's that are
owned by HP...  I won't spend personal money on hardware I can't have driver
source for.

Bdale