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Index > OS Construction > [ask]vesa bank switching problem

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christiandy



Joined: 03 Mar 2011
Posts: 25
Location: 101
christiandy
how to use bank switching function ax 4f05 int 10h? I try to make myself but it did not work. I try to write to pixel 400 which is on bank 5 cmiiwbut it still wrote in the first pixel.
Code:
setbank:
 pushad
      mov ax,0x4f05
       xor bx,bx
   mov dx,[bank]
       shl dx,4
    int 10
      popad
       ret
    


my put pixel function
Code:
putpixel: 
;put pixel direct to VGA memory (x,y,color)
   
pushad      
     

        
        MOV     CX,[X] 
        MOV     AX,[Y] 
        ROL     AX,9
        MOV     BX,AX 
        ADD     AX,CX 
        SHR     BX,2 
                xor cx,cx
        ADD     BX,AX 
         JNC NOC
             inc cx
              NOC:
            cmp cx,[bank]
               jz same
             mov [bank],cx
               call setbank
                same:
               PUSH    0A000H 
        POP     ES
           MOV     [ES:BX],DL              ; Write Pixel 
  popad
        RET 
    
Post 23 Apr 2011, 18:34
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Mac2004



Joined: 15 Dec 2003
Posts: 313
Mac2004
Your setbank routine calls int 10 instead of int 0x10.

Regards
Mac2004
Post 23 Apr 2011, 19:31
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christiandy



Joined: 03 Mar 2011
Posts: 25
Location: 101
christiandy
oh thanks. but i still can't control it if i put pixel to y=400 it will drawn on y= aproximately 100
Post 24 Apr 2011, 07:01
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