Int 14 Fn B1 - 3com Bapi Serial I/o - Enter Command Mode [S]
AH = B1h
Return: AH = return code (00h,07h,0Ah) (see #0320)
Desc: provide a means for the application or terminal emulator to perform
the same action normally caused by the ECM character
See Also: AH=B0h,AH=B2h