Int 6F Fn 8A  - 10net V5.0 - Chat                                          [N]

   AH = 8Ah
   DS:BX -> chat parameters (see below)
   DS:DX -> chat message (see below)

Return: CF clear if successful
   CF set on error
       AX = status (see AH=00h)

See Also: AH=0Ah

Format of chat parameters:
Offset Size    Description
 00h  8 BYTEs  sender's user name
 08h  8 BYTEs  destination user name
 10h 15 BYTEs  destination node (0 if broadcast-style chat)

Format of chat message:
Offset Size    Description
 00h   WORD    message length
 02h  N BYTEs  chat message contents