From: "Michael Stewart" <mike AT reggin DOT freeserve DOT co DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: more problems settings the correct mode
Date: Tue, 30 Mar 1999 19:09:40 +0100
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

...
>Mode 0x76 :   640x480   32 bpp direct color (RGB 888)
Don't hardcode the mode numbers into your program. From VESA 2 and above
there is no guarantee that the mode numbers will refer to the same
resolution and colour depth.

>seeing the mode numbers off to the left side, i also tried ot use the old
>setmode function i was using before i had allegro. the call to the funciton
>in my code looks liek this:
>setmode(0x111);
>here is the code for the function, which requires either the <dpmi.h>
header
>file or the <sys/movedata.h> file (not sure which)
>void setmode(int mode)
>{
>   __dpmi_regs r;
>
>   r.x.ax = mode;
>   __dpmi_int (0x10,&r);
>}
>

This won't work. You're trying to set a VESA mode with a VGA mode set
routine. You need something a little different :

bool VESA_set_mode (int mode) {
   __dpmi_regs r;

   r.x.ax = 0x4F02; // VESA set mode function
   r.x.bx = mode;

   __dpmi_int (0x10, &r);

   if (r.h.ah) return (false); // An error setting the mode has occured

   return (true);
}

This is the minimum you need to set the VESA mode.

If you need some more sample VESA code then take a look at the Allegro
source, or email me direct and I'll send you some.

Michael Stewart
mike AT reggin DOT freeserve DOT co DOT uk
"Just because you're paraniod doesn't mean they aren't after you..."