检测鼠标移动并在屏幕上显示的问题（环境：DOS + SVGA + turbo c）

Question

我打算调用BIOS中断功能来检测鼠标的位置，我认为如果我恢复屏幕上显示的鼠标的原始区域然后＆＃34;绘制＆＃34;它在新的位置。

但这是我的程序的结果：鼠标的图像将在屏幕上显示，图像将仅响应一次。然后程序将被卡住，直到我强行结束。

我使用的是dosbox来模拟dos环境。我的开发环境是turbo c 3.0。我在vesa vbe下编程支持svga模式（turbo c并不完全支持）。代码：

    #define MOUSEX 200
    #define MOUSEY 200
    int MouseInit() // checking if the driver of mouse is installed
    {
        int retcode;
        asm{
            mov AX,0
            INT 33h
            mov retcode,AX
        }

        if(retcode==0) // uninstalled
            return 0;

        return retcode;
    }

    void SetXY() // set range of mouse movement
    {
        asm{
            mov AX,7
            mov CX,0
            mov DX,639 // range of x:0-639
            INT 33h
            mov AX,8
            mov CX,0
            mov DX,479 // range of y:0-479
            INT 33h 
        }
    }

    void setmouse(INT16 x,INT16 y) // set the location of mouse
    {
        asm{
            MOV CX,x
            MOV DX,y
            MOV AX,4
            INT 33H
        }
        xpos = x;
        ypos = y;
    }
    /*
    INT 33H:
    AX = 000Ch // go to user's function when certain acts of the mouse occur
    CX = call mask // define the conditions that will trigger user's interrupt function
      bit 0 call if mouse moves 
      bit 1 call if left button pressed 
      bit 2 call if left button released 
      bit 3 call if right button pressed 
      bit 4 call if right button released 
      bit 5 call if middle button pressed (Mouse Systems/Logitech
              mouse)
      bit 6 call if middle button released (Mouse Sys/Logitech mouse)
    ES:DX -> FAR routine
    Notes:  when the subroutine is called, it is passed the following values
    AX = condition mask (same bit assignments as call mask 
    BX = button state 
    CX = cursor column 
    DX = cursor row
    SI = horizontal mickey count 
    DI = vertical mickey count
   */
void interrupt mousehandler()
{
    int newevent,newxpos,newypos;
    int i,j;
    asm{
        MOV newevent,AX
        MOV newxpos,CX
        MOV newypos,DX
    }
    switch(_AX){
    case 0x01:
        ConcealMouse(xpos,ypos,origin); //clear former mouse image 
        xpos=newxpos;ypos=newypos; // obtain new location of mouse
        for(i=0;i<16;i++)   // save original image of the screen in that new location
           for(j=0;j<16;j++)
               origin[i*16+j]= GetPixel(xpos+j,ypos+i);
        DrawMouse(xpos,ypos); // display mouse in new location(draw the 16*16 lattice on the screen)
 }

}
void installtask(INT16 mask)
{
    asm{
        MOV AX,0CH
        MOV CX,mask
        MOV BX,SEG mousehandler
        MOV ES,BX
        LEA DX,mousehandler
        INT 33H
    }
}

void ShowMouse()
{
    int i,j;

    if(MouseInit()==0){
        SetSVGAMode(3);
        printf("no mouse available!\n");
        exit(1);
    }
   SetXY(); 
   setmouse(MOUSEX,MOUSEY);

   for(i=0;i<16;i++)    // save original image of the screen
       for(j=0;j<16;j++)
           origin[i*16+j]= GetPixel(xpos+j,ypos+i);
   DrawMouse(xpos,ypos); // draw mouse in the given location
   installtask(0x007f);  // waiting for interruption
}

我很确定绘制鼠标和隐藏它的功能是正确的，因为我测试过它。中断功能是失败的原因吗？希望得到你的回答，非常感谢。