| 
 |  | 
                DOS INTERNAL SERVICES - Position File Pointer                 
  
    | 
       Input  | 
    DOS1 | 
    N | 
    DOS2 | 
    N | 
    
       DOS3  | 
    Y | 
    DOS5 | 
    Y | 
    
       Output  | 
   
  
    | 
       AX  | 
    12h | 
    28h | 
     New
      Offset (Low) / Error Code | 
    AX | 
   
  
    | 
       BX  | 
     File
      Handle | 
      | 
      | 
    BX | 
   
  
    | 
       CX  | 
     Offset
      (Low) | 
      | 
      | 
    CX | 
   
  
    | 
       DX  | 
     Offset
      (High) | 
    New
      Offset (High) | 
    DX | 
   
  
    | 
       BP  | 
     Seek
      Code (as per call 42h) | 
    Set
      if Error | 
    CF | 
   
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