INT 67 - LIM EMS 4.0 - ALTER PAGE MAP AND JUMP
        AH = 55h
        AL = subfunction
            00h physical page numbers provided by caller
            01h segment addresses provided by caller
        DX = handle
        DS:SI -> structure containing map and jump address
Return: (at target address unless error)
        AH = status
            00h successful
            80h internal error
            81h hardware failure
            83h invalid handle
            84h undefined function requested
            8Ah invalid logical page number encountered
            8Bh invalid physical page number encountered
            8Fh invalid subfunction