Int 7F Fn 03  - Alloy Ansk, Ntnx, Mw386 - Get User Number                  [N]

   AH = 03h

Return: AL = user number
   AH = machine number (MW386)

Note:  this function call is the recommended method for a CPU-bound process to
     prevent its priority from being lowered

See Also: AH=04h,AH=05h,AH=A1h