Mail Archives: djgpp/1998/09/29/12:00:41
From: | "Bob Koon" <loganproductions AT SPAMFREE DOT internetmci DOT com>
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | Problem with Direct Video Memory Access
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Lines: | 28
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Message-ID: | <vF6Q1.278$Fh.320270@news.cwix.com>
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Date: | Tue, 29 Sep 1998 10:05:34 -0500
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NNTP-Posting-Host: | 166.55.208.244
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NNTP-Posting-Date: | Tue, 29 Sep 1998 15:03:55 GMT
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Organization: | CWIX
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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Hi folks...
I have a problem with trying to draw (or even transfer) stuff directly to
video memory. I'm using the far pointer method to access the screen and it
works when I call it _before_ any memory allocations, but as soon as I put
the code where I want it, I get nothing. (I get exactly the same results
with all three methods of direct video access.) What am I (not) doing to
cause this?
Below is the code fragment I'm using:
/* draw some dots to the screen */
_farsetsel(_dos_ds);
_farnspokeb(0xa0000, 1);
_farnspokeb(0xa0002, 2);
_farnspokeb(0xa0004, 3);
_farnspokeb(0xa0006, 4);
_farnspokeb(0xa0008, 5);
Thanks in advance for the help.
-- Bob
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