Expects: AX    0013H
DX    doubling limit, in mickeys-per-second
                                                                  
Returns: none
                                                                  
Info: When the mouse is moved quickly, the mouse support doubles the
distance of the motion of the pointer.  This makes it possible to
use slow, fine motions for detail work without sacrificing speedy
motion to move quickly across the screen.

By default, if the mouse moves 64 mickeys per second (about 1/3rd
inch per second), the mouse support doubles the pointer motion.
If you prefer more acceleration, use values smaller than 64 in
DX.  For less acceleration, use larger values.  To effectively
eliminate this speed-doubling, use a large values, such as 10,000
in DX.

You can also set this threshold via INT 33H 001aH and query its
current value via INT 33H 001bH.

- -

INT 33H 0013H: Set Speed-Doubling Threshold