Returns: BX 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
CX X coordinate (horizontal) divide by 8 for text clm
DX Y coordinate (vertical) divide by 8 for text line
Info: This returns the current position of the mouse pointer, and the
current status of the mouse buttons.
Rather than constantly polling this function, many programmers
INT 33H 0018H and maintain global variables for instant access to
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