Int 16 Fn 55FE  CU - Microsoft Qbasic Internal - Microsoft Cooperation Wi  [A]

   AX = 55FEh
   DX = 0000h
   ES:BX -> ??? function
   ES:CX -> ??? structure

Return: AX = result
       4D4Bh only the INT 1B handler will be installed.
       <> 4D4Bh handlers for INT 08, INT 09, INT 16, INT 1B, and
         INT 1C are installed

Notes: The pointer in ES:CX seems to point at a structure defining a callback
     function when new keyboard keys are pressed. If a TSR returns
     AX=4D4Bh, QBASIC will stop (with IRQ's and interrupts enabled).

See Also: INT 16/AX=5500h,INT 1A/AX=3601h