INT 6F - 10NET v5.0 - CHAT                                                      
	AH = 8Ah
	DS:BX -> chat parameters (see #03777)
	DS:DX -> chat message (see #03778)
Return: CF clear if successful
	CF set on error
	    AX = status (see #03740)
SeeAlso: AH=0Ah"10NET"


Format of 10NET chat parameters:
Offset	Size	Description	(Table 03777)
 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 10NET chat message:
Offset	Size	Description	(Table 03778)
 00h	WORD	message length
 02h  N BYTEs	chat message contents