Int 62 Fn 0B  - Cswitch - Send Message                                     [T]

   AH = 0Bh
   CX = number of bytes to write
   DS:SI -> buffer
   DX = queue number (0-63)

Return: AX = result/message size
       0000h no message was on queue
       FFFEh triggered by something arriving, redo the call
       FFFFh bad queue number
       else  number of bytes in message

See Also: AH=0Ah"Cswitch",AH=0Ch"Cswitch"