About VESA. I checked out a few stuff on VESA and I realized that it isn't as simple as VGA (mode 13h).

;=========================================================;
; Vesa                                         02/02/2011 ;
;---------------------------------------------------------;
; By Dex.                                                 ;
;                                                         ;
; Here is a simple "Vesa" program.                        ;
; for Dos32, using the calltable functions.               ;
; To assemble in Dos32, use fasm as follows               ;
; fasm vesa1.asm vesa1.dex                                ;
;=========================================================;
use32
     ORG   0x400000          ; where our program is loaded to
    jmp   start             ; jump to the start of program.
     db    'DEX3'          ; We check for this, to make shore it a valid 32bit dos file.
 ;----------------------------------------------------;
 ; Start of program.                                  ;
 ;----------------------------------------------------;
start:
        mov     ax,18h                                 
     mov     ds,ax                                  
     mov     es,ax                                 
 ;----------------------------------------------------;
 ; Get int21h address.                                ;
 ;----------------------------------------------------;
     mov     eax,21h                               ; get the int 21h address
     int     21h
 jc      Int21hError
 mov     dword[Int21h],eax                     ; store it
 ;----------------------------------------------------;
 ; Get calltable address.                             ;
 ;----------------------------------------------------;
   mov     edi,Functions                         ; fill the function table
     mov     al,0                                  ; so we have some usefull functions
   mov     ah,0x0a
     int     50h
 ;----------------------------------------------------;
 ; set vesa up                                        ;
 ;----------------------------------------------------;
        mov     ax,4f00h                              ; Set the vesa mode
   mov     bx,0x4115
   mov     edi,Mode_Info                         ; fill in vesa info
   call    [RealModeInt10h]
    jc      Int21hError               
 ;----------------------------------------------------;
 ; fade and send to screen                            ;
 ;----------------------------------------------------;
 call    fade_screen32_8001                    ; fill the off screen buff with color
 call    BuffToScreen                          ; write it to screen
 ;----------------------------------------------------;
 ;  wait for keypress                                 ;
 ;----------------------------------------------------;
 mov     ah,07h                                ; function number
     call    dword[Int21h]                         ; wait for keypress
 ;----------------------------------------------------;
 ; return to text mode                                ;
 ;----------------------------------------------------;  change back to text mode
        mov     ax,03h                                ;  move the number of the mode to ax
  call    [RealModeInt10h]                      ;  and enter the mode using int 10h
 ;----------------------------------------------------;
 ; print string                                       ;
 ;----------------------------------------------------; print a message
  mov     edx,Text_msg                          ; this point's to our string.
        mov     ah,09h                                ; function number
     call    dword[Int21h]                         ; this call dos function.
     ret                                           ; returen to CLI
 ;----------------------------------------------------;
 ;  exit error                                        ;
 ;----------------------------------------------------;
Int21hError:                                          ; If error we end up here
 ;----------------------------------------------------;
 ; print string                                       ;
 ;----------------------------------------------------;
     mov     edx,Error_msg                        ; this point's to our string.
 mov     ah,09h                                ; function number
     call    dword[Int21h]                         ; this call dos function.
     ret
;----------------------------------------------------;
 ; BuffToScreen.  ;Puts whats in the buffer to screen ;
 ;----------------------------------------------------;
BuffToScreen:                                         ; test for 24bit or 32bit vesa
     cmp     [ModeInfo_BitsPerPixel],24
  jne     Try32
       call    BuffToScreen24
      jmp     wehavedone24
Try32:
  cmp     [ModeInfo_BitsPerPixel],32
  jne     wehavedone24
        call    BuffToScreen32 
wehavedone24:
@@:
     ret

 ;----------------------------------------------------;
 ; BuffToScreen24                               32bpp ;
 ;----------------------------------------------------;
BuffToScreen32:
      pushad
      push    es
  mov     ax,8h
       mov     es,ax
       mov     edi,[ModeInfo_PhysBasePtr]
  mov     esi,VesaBuffer 
     xor     eax,eax
     mov     ecx,eax        
     mov     ax,[ModeInfo_XResolution]
   mov     cx,[ModeInfo_YResolution]
   mul     ecx
         mov     ecx,eax        
     cld
         cli
         rep     movsd
       sti
         pop     es
  popad
       ret


 ;----------------------------------------------------;
 ; BuffToScreen24                               24bpp ;
 ;----------------------------------------------------;
BuffToScreen24:
         pushad
      push    es
  mov     ax,8h
       mov     es,ax
       xor     eax,eax
     mov     ecx,eax
     mov     ebx,eax 
    mov     ax,[ModeInfo_YResolution]
   mov     ebp,eax
     lea     eax,[ebp*2+ebp]
     mov     edi,[ModeInfo_PhysBasePtr]
  mov     esi,VesaBuffer  
    cld
.l1:
     mov     cx,[ModeInfo_XResolution]
   shr     ecx,2       
.l2:
    mov     eax,[esi]       
    mov     ebx,[esi+4]     
    shl     eax,8           
    shrd    eax,ebx,8       
    stosd


       mov     ax,[esi+8]      
    shr     ebx,8           
    shl     eax,16          
    or      eax,ebx         
    stosd


       mov     bl,[esi+10]     
    mov     eax,[esi+12]    
    shl     eax,8           
    mov     al,bl           
    stosd


       add     esi,16
      loop    .l2


         sub     ebp,1
       ja     .l1


  pop     es
  popad
       ret


 fade_screen32_8001:
     pushad
      mov    edi,VesaBuffer
       mov    eax,0x00ffffff
       mov    ecx,800*600
  rep    stosd
        popad
       ret



 ;----------------------------------------------------;
 ; Data.                                              ;
 ;----------------------------------------------------;
VesaBuffer =    0x800000
count      db   0
Int21h       dd   0
Error_msg: db  'No vesa found! ',13,10,'$'
Text_msg:  db  'Text mode ',13,10,'$'


include 'Dex.inc'                                   ; Here is where we includ our "DexFunctions.inc" file