Int 14 Fn EC  - Telapi - ???                                               [N]

   AH = ECh
   BX = ???
   CX:DX = ???
   DS:DI -> ???
   ES:SI -> ???

Return: AX = status (0000h,FF37h,etc.)
   ES:SI -> ??? if ???
   ???

Note:  this function is not supported by the Microdyne TelAPI v3.7

See Also: AH=E0h"TelAPI",AX=FF00h