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From: j@uriah.sax.de (J Wunsch)
Newsgroups: comp.os.386bsd.development
Subject: Re: [FreeBSD 1.0R] DMA Problems?
Date: 7 Jan 1994 18:00:35 +0100
Organization: Private U**X site; member IN e.V.
Lines: 45
Message-ID: <2gk4fjINNal@bonnie.sax.de>
References: <CHCErs.G5w@genesis.nred.ma.us> <2dj25i$1ga@u.cc.utah.edu> <2encotINN3sq@bonnie.sax.de> <2eqjt7$dqm@u.cc.utah.edu> <CI6291.HBA@genesis.nred.ma.us> <2fbvtoINNk71@bonnie.sax.de> <jmonroyCIJFAr.Atn@netcom.com> <2g4kjvINNnsf@bonnie.sax.de> <jmonroyCJ3ts3.1Ls@netcom.com>
NNTP-Posting-Host: bonnie.sax.de
jmonroy@netcom.com (Jesus Monroy Jr) writes:
>: Yes. But this doesn't prove they do the refresh via an DMA channel zero
>: request. They simply continue using the timer...
>:
> If this doesn't prove the point please state why.
You showed the dependance between the timer and the dRAM refresh. But you
_assumed_ the timer would control DMA channel 0 without proving this. I
claim this is wrong.
> I am sorry to seem a bit irritated on this but, I
> seem to bring facts and proof.[...]
If your claim were correct, shutting down the DMA controller would cause
the dRAM refresh to stop and thus immediately shut down any system.
Well i simply wrote a ``4'' onto port ``8'', this should disable the
DMA controller. I can prove it does since the floppy fails after this
step. But my dRAMs are quite well:-)
> Blink... what does "all of the modern chipsets" mean?
> Does this mean chipsets made after 1992/1991/1990?
The above test has been made on a NEAT chipset, production time 9038. Just
to prove it once more, i've tested it on any available DOS box here, some
286, some 386, with the same result. (All those boxes are from the early
90's.)
Any piece of documentation that *i* have states that DMA 0 is unused in
AT-style computers.
> And please explain to me why your not reading the Data Guide?
^^^^
you're? Must i teach you English?
Which Data Guide? Where should i read it? Why should i read it?
I hope i gave you enough ``facts and proof'' now. Please don't waste my
time anymore.
--
in real life: J"org Wunsch | ) o o | primary: joerg_wunsch@tcd-dresden.de
above 1.8 MHz: DL 8 DTL | ) | | private: joerg_wunsch@uriah.sax.de
| . * ) == |
``An elephant is a mouse with an operating system.''