Int 5B Fn 8485  U - Sitback V3.02r - Set ??? Flag And Get ??? Address      [U]

   AX = 8485h
   DL = 71h

Return: ES:BX -> FAR entry point to ???

Note:  the flag which is modified is located at the address returned by
      AX=5254h/DL=04h

See Also: AX=8485h/DL=72h