X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f
Date: Thu, 16 Dec 2004 09:16:08 +0100
From: Egon Eckert <egon AT heaven DOT industries DOT cz>
To: djgpp AT delorie DOT com
Subject: Re: Problems with timer interrupt chaining and SmartDrv
Message-ID: <20041216081608.GA17913@webhome.cz>
References: <001701c4e2f2$e397dcc0$e1b92951 AT josepmariaxp> <01c4e32a$Blat.v2.2.2$fb750ba0 AT zahav DOT net DOT il>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <01c4e32a$Blat.v2.2.2$fb750ba0@zahav.net.il>
User-Agent: Mutt/1.5.6+20040722i
Sender: Egon Eckert <egon AT webhome DOT cz>
Reply-To: djgpp AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: djgpp AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com
Precedence: bulk

> > I thing the problem is that smartdrv uses dma to write to disk.
> 
> This cannot be true, IMHO, since most disks use programmed I/O, not
> DMA.

(sorry for a slight off-topic)

What a surprise!  I thought DOS does the disk IO through BIOS, which
should know how to talk to the IDE controller efficiently (for the
onboard at least)...  May be modern BIOSes don't bother to try to
support DOS doing just the lazy PIO (easier to implement, I suppose)
instead of DMA?

-- 
Egon Eckert, Heaven Industries, s.r.o.
E-mail: egon AT heaven DOT industries DOT cz

Never be afraid to try something new. Remember, amateurs built the
ark; professionals built the Titanic. -- Anonymous