From: deisenzi AT d DOT umn DOT edu
Newsgroups: comp.os.msdos.djgpp
Subject: VGA, VESA; making DOS graphics
Date: 9 Mar 2000 18:14:47 GMT
Organization: University of Minnesota - Duluth
Lines: 34
Message-ID: <8a8pmn$blp$1@news.d.umn.edu>
NNTP-Posting-Host: bulldog5.d.umn.edu
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

Hello all, I have successfully written some code that uses the VGA driver 
but I would like to make graphics with a higher resolution.  I am using a 
dinosaur (486) and it's a Compaq (no flames please).  The current display 
setting used by Windows is...
Compaq/ET4-W32 640X480 256 color

Apparently some other display drivers are available because I am able to 
change to these but the monitor is not displaying them properly (hazy, 
triple-image).  The ones that I have been trying have a resolution of 800X600, 
example being the Super VGA.

I am not sure if VESA is available to me.  I have looked through the VESA 
code provided at www.delorie.com and get the following results when I run 
the code.  Obviously this is not the complete code that I used:

  /* call the VESA function */
  r.x.ax = 0x4F00;
  r.x.di = dosbuf & 0xF;
  r.x.es = (dosbuf>>4) & 0xFFFF;
  __dpmi_int(0x10, &r);

  /* quit if there was an error */
  if (r.h.ah)
    return -1;
    
The expression (r.h.ah) is asserted when I run the program.

Does this mean that, without a doubt, VESA is not available to me?

Can anyone offer some help, or am I pretty much stuck with the VGA?

thanks,
Darren