Int 14 Fn 57  U - Bwcom14 - Initialize                                     [S]

   AH = 57h
   DL = port number

Return: AL = initialization status (00h successful, 01h already initialized)
   CX = port status (0001h port redirected, 0002h and FFFFh failed)

Note:  after this call, all invocations of INT 14/AH=00h-03h for the specified
     port will be handled by BWCOM14 until AH=58h is called

See Also: AH=00h"SERIAL",AH=56h,AH=58h