Expects: AX    0006H
BX    Button to query (0=left, 1=right, 2=center)
                                                                  
Returns: AX    Button status: bit 0 = left button down   (BX & 1) == 1
bit 1 = right button down  (BX & 2) == 2
bit 2 = center button down (BX & 4) == 4
BX    Count of times that button was released since last call
CX    X coordinate (horizontal pixel) at last release
DX    Y coordinate (vertical pixel) last release
                                                                  
Info: This obtains:
  The current button status.
  The number of times the specified button (in BX) has been
released since the last call to this function.
  The X,Y coordinates of the pointer at the time of the most
recent release of that button.

Notes: All X,Y coordinates are virtual coordinates and when working with
text mode, you must divide each value by 8 to get a character
clm,row.

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INT 33H 0006H: Query Button-Released Counter