Vesa in nasm
 

Hello!

3 weeks ago I started to search the secrets of vesa programming... and now I can forwrd with this problem.. :( I know I learning very slow, but... I think the important is that I want to learn :mrgreen: So here is my code:

section .code





start:

  mov        ax,data

  mov        ds,ax

  mov        es,ax

  mov        ax,stack

  mov        ss,ax

  mov        sp,stacktop

  jmp        main





PutPixel:

  push eax

  push es

  push ecx

  push edx

  push ebx

  lea eax,[edx+4*edx]

  lea eax,[eax+4*eax]

  xor edx,edx

  mov ebx,65536

  shl eax,5

  add eax,ecx  

  div ebx

  mov ecx,edx

  cmp eax,CurBank

  je Lbl

  mov [CurBank],eax

  mov dx,ax

  mov ax,4f05h   ;SetBank

  xor ebx,ebx

  int 10h

  Lbl:

     pop ebx

     mov ax,0A000h

     mov es,ax

     mov [es:ecx],bl 

     pop edx 

     pop ecx

     pop es

     pop eax

ret





main:

  mov        ax,0x4f02

  mov        bx,0x103

  int        0x10



;-----------------------------------------

      mov bl,1            ;color

      xor edx,edx

      LoopY:

         xor ecx,ecx

         LoopX:

            call PutPixel

            inc ecx

            cmp ecx,800

            jne LoopX

         inc edx

         inc bl

         cmp edx,256

         jne LoopY

;-----------------------------------------

  xor  ah,ah

  int  16h



  xor        ah,ah

  mov        al,0x3

  int        0x10



  mov        ax,0x4c00

  int        0x21





section  .data

  s                resb        256

  CurBank  dd         0

section .stack stack

 resb 2048

stacktop:

I wrote this code in nasm. And then used tlink. The problem is that this is very very slow for filling the screen... I know that I have to use the video memory.. but I can't.. :( I read many tutorials but I still can't use.. Tutorials didn't write an example :(
Please if somebody can help me to do a faster code or something... Thanks in forward

Re: Vesa in nasm
 

hi you should change the code

mov ax,4f05h   ;SetBank

to read

mov ax,4f02h   ;SetBank

I think the problem is your bios support for vesain mode 4f05h