Xref: news2.mv.net comp.os.msdos.djgpp:7813
From: "Justin Frankel" <mud AT sedona DOT net>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Screen Read problems (mode 13h)
Date: 23 Aug 1996 16:11:04 GMT
Organization: Nullsoft
Lines: 54
Message-ID: <01bb9105$305a2a20$793055ce@Pmud>
References: <3216B47D DOT EDA AT sprynet DOT com>
NNTP-Posting-Host: client51.sedona.net
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp



John Luebs <jkluebs AT sprynet DOT com> wrote in article
<3216B47D DOT EDA AT sprynet DOT com>...
> I use this function to put a row of pixels into the video buffer
> offset is an int that contains the starting pixel value
> work_back is a long* to the data to be put to the screen, and
> sprite_width
> is the number of pixels in the transfer.
> 
> This function works fine!
> __asm__ __volatile__ ("pushw %%es\n
>     		movl $0xa0000h, %%edi\n
>     		addl %0, %%edi\n
>     		movw %1, %%es\n
>     		movl %2, %%esi\n
>     		movl %3, %%ecx\n
>     		cld\n
>     		rep\n
>     		movsb\n
>     		popw %%es\n"
>     		:
>     		: "g" (offset), "g" (_dos_ds), "g" (work_back), "g" (sprite_width)
>     		: "cx", "di", "si"
>     	);
> 
> I use this to do the opposite, however I get GPFs. Any Suggestions??
> 
> __asm__ __volatile__ ("pushw %%ds\n
>  		pushw %%es\n
>  		movw %%ds, %%ax\n
>  		movl $0xa0000h, %%esi\n
>     		addl %0, %%esi\n
>     		movw %1, %%ds\n
>     		movl %2, %%edi\n
>     		movw %%ax, %%es\n
>     		movl %3, %%ecx\n
>     		cld\n
>     		rep\n
>     		movsb\n
>     		popw %%es\n
>     		popw %%ds\n"
>     		:
>     		: "g" (offset), "g" (_dos_ds), "g" (work_back), "g" (sprite_width)
>     		: "ax", "cx", "di", "si"
>     	);
> 
> Any help appreciated!
> 
> John Luebs
> 

Try loading DS after loading ecx, edi, and esi. 
Justin