VideoID v/2.0: written by Bob Berry, Canyon State Systems -> Public Domain 
 Step/function______ method__________________ ah al bh bl ch cl dh dl result
 1. Look for VGA     video int ax=1A00h       00 1A 00 08 00 00 00 00 FOUND 
 2. Look for EGA     video int ah=12h bl=10h                          skip  
 3. Look for CGA     find 6845 CRTC at 3D4h                           skip  
 4. Look for MDA     find 6845 CRTC at 3B4h                           skip  
 5. Look for HERC    check MDA status port                            skip  
 6. Identify active  single display is active                               
        Active Video=VGA adapter, PS/2 color monitor.                       
      Inactive Video=(none).                                                
 7. Peek at EGA/VGA video RAM at C000:0000                                  
  |U.@.H740007.}**  RESERVED FOR IBM COMPATIBILITY **.8....10/25/91.. C3.0 |
  |     ....Copyright 1988-1991 TRIDENT MICROSYSTEMS INC......Copyright 198|
  |7-1990 Quadtel Corp...... 256.. 512.. 768..1024..K  ..VGA..EGA..CGA..MDA|
 8. Identify VGA (and video memory, if possible).                           
   IBM 8514/a..no          IBM XGA.......no          Hercules GS..no        
   Ahead A.....no          Ahead B.......no          Everex.......no        
   Tseng 3000..no          Tseng 4000....no          Genoa GVGA...no        
   Trident.....no          Trident 8900..no          ATI..........no        
   Video 7.....no          Paradise......no          Oak Tech.....no        
   Compaq......no          Chips & Tech..no          NCR..........no        
   VBE (VESA)..FOUND ???k  DGIS..........no