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Don,

I was wrong in thinking that READ LONG/WRITE LONG was tied into the recent
addressing changes (I got the timing confused in my mind with the SEEK
command, which has just been proposed to become obsolete).  In reality READ
LONG/WRITE LONG were made obsolete in ATA-4 back in August of 1997 (actually
in revision 5 of that document in June of 1996).

So they have not appeared in ATA-4, ATA-5, or ATA-6 (or the upcoming ATA-7).
It has not been in a draft document for more than 5 years.  Every one of
those standards have advised hosts not to use that command anymore, since
devices are compliant while only returning a command aborted in response to
the command.

Indeed, they only appear in ATA-1, ATA-2, and ATA-3.  ATA-1 and ATA-2 are
withdrawn standards (i.e. they no longer exist except as historical
footnotes), so the only standard they are mentioned in is ATA-3.

So the issue is rather academic (unless, once again, people have a new
proposal on some new functionality to make).

The current issues are obsoleting the SEEK command and CHS addressing mode.

Jim


-----Original Message-----
From: don clay [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, March 19, 2002 2:27 PM
To: ata reflector
Subject: [t13] Re: ^ 18 R/W Long commands


This message is from the T13 list server.


Jim,

I have over 26 years of experience with multiple disk drive companies, both
big
box and in ATA drives with long runs of service with two different
companies.  I
have designed ATA ASIC's and written the code for them.  I have been
involved
in the development of ATA drives since mid 1986. 

So I have designed the R/W Long command in several ASIC's and then written
the code for those commands.  Both the code and the ASIC's have shipped
successfully in very large volumes.

I have been intimately involved in the testing and development of all of
these
drives in very many different ways.  I have worked closely with many
different
customers and understand how they used to want drives tested and how they
want them tested in the present.

Furthermore, I have worked very closely with other OEM's in the development
of
their ASIC's  for the ATA Interface.  That technology also shipped in very
large
volumes.

It has been my experience that you are wrong in this matter both on the
hardware and firmware side of this discussion.  I have provided examples
supporting my position and could supply more if necessary.  These assertions
are based on actually designing and testing ASIC's, doing the code for them,
and then designing tests for them.

I entered this thread because the ATA committee is continually  short
sighted in
it's approach to backward compatibility.  It has repeatedly acted without
considering the whole of the ATA interface community.  This has been true
since the inception of this standards effort, which I also witnessed first
hand.

This thread began with several people complaining about the obsolescence of
the R/W Long commands.  The committee obviously did not poll the
constituency of the ATA community prior to making the decision to obsolete
the
R/W Long commands as several people have noted.  Obsoleting a command,
as I've stated many times prior to this, subjects companies that are using
such
commands  to the whims and politics of this committee.

People should not have to come to these meetings out of self defense.
People
who are on the committee should have the responsibility to look at the big
picture and all of the members on it when considering changes.  That would
be
a good use of this reflector.

Your last paragraph is an example of that.  Burden of proof????  The ATA
committee should be comprised of members who are going to exercise due
dilligence prior to making a change.

It is totally irrevalent how the R/W Long command is being used.  People are
using it.  And that is burden of proof enough.

don clay

3/19/02 1:23:57 PM, "McGrath, Jim" <[EMAIL PROTECTED]> wrote:

>
>Don,
>
>First, not all opinions are equal.  I've worked at a disk drive company for
>15 years, and I know whereof I speak.  Perhaps more importantly, a lot of
>folks on T13 are equally well educated on these sorts of issues.  You keep
>on asserting no there are costs, despite the facts that they're been
>outlined to you.  You are just not listening - so I'll stop talking.
>
>Second, the burden of proof is always on people advocating change - in this
>case to add READ/WRITE LONG back into the standard.  My (constructive)
>suggestion has been to put together a proposal that accomplishes what
people
>want (whether that's really testing ECC, error injection, marking sectors,
>etc...) and submit it to T13.  Or even wait until it is published and offer
>a public comment.  If you are not willing to make the effort, then it's
>obviously not a very important topic for you.
>
>Jim
>>>

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