Sender: "Rolf Campbell" <cp1v45 AT nortelnetworks DOT com>
Message-ID: <37C5544E.350B4482@NortelNetworks.com>
Date: Thu, 26 Aug 1999 10:50:54 -0400
From: "Rolf Campbell" <cp1v45 AT nortelnetworks DOT com>
Organization: Nortel Networks
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Newsgroups: comp.os.msdos.djgpp
To: djgpp AT delorie DOT com
Subject: Re: MSCDEX Data Block Headers
References: <19990825102051 DOT 84665 DOT qmail AT hotmail DOT com>
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Reply-To: djgpp AT delorie DOT com

Niko Salminen wrote:

> I have a piece of code which uses IOCTL functions at the CDRom drive, but
> for some reason, when I pass the data block's transfer address with the
> in/output call, MSCDEX keeps finding only zeros at that location.
>
> For example, if I want to close the tray, I send MSCDEX my IOCTL output
> block with a pointer to an unsigned char which contains the value 5
> (CLOSE_TRAY). The result is that the tray opens.
>
> The transfer address expects a far pointer (the original routine was
> real-mode) but I just pass the protected mode address as-is. I even tried
> reserving mem from the first 640kB and passing it's address, but then even
> the tray didn't open with the proper function.

    The FAQ tells how to transfer addresses to a real-mode driver.

--
     -Rolf Campbell (39)3-6318