From:	"John F. Bell" <jbell AT xmission DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	__djgpp_conventional_base
Date:	Sun, 13 Oct 1996 15:23:46 -0600
Organization:	XMission Internet (801 539 0900)
Lines:	27
Message-ID:	<32615DE2.4928@xmission.com>
Reply-To:	jbell AT xmission DOT com
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

how often does __djgpp_conventional_base change in a program?
I am using the method of enabling near pointers to access video memory
and I access it by unsigned char *video_buffer=(unsigned char
*)0xA0000+__djgpp_conventional_base;

Is this the fastest way to access video memory?
Do I need to declare video_buffer as
unsigned char *video_buffer=(unsigned char *)0xA0000;
and access it by *video_buffer[__djgpp_conventional_base]?

Also, I tried to write a screen filler function in assembly, but it 
only fills up the first half of the screen or so.  Here it is
__asm__ __volatile__ ("
movl %1, %%edi
movb %0, %%al
movw 64000, %%cx
rep
stosb"
:
:"g" (color), "g" (0xA0000+__djgpp_conventional_base)
:"ax","cx","di","memory"
);
What's wrong with this?
Thanks in advance.

John F. Bell
<no email currently>

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