INT 21 - Novell NetWare - MESSAGE SERVICES - SET BROADCAST MODE                 
	AH = DEh
	DL = broadcast mode
	    00h receive server and workstation broadcasts (default)
	    01h receive server broadcasts, discard user messages
	    02h store server broadcasts for retrieval
	    03h store all broadcasts for retrieval
Return: AL = new broadcast mode
Note:	this function is supported by NetWare 4.0+ and Advanced NetWare 1.0+
                                                                                

INT 21 - Novell NetWare - SHELL TIMER INTERRUPT CHECKS                          
	AH = DEh
	DL = function
	    05h disable shell timer interrupt checks
	    06h enable shell timer interrupt checks
Return: ???
Note:	this function was added in NetWare 4.0, but is not listed in current
	  Novell documentation and is probably no longer supported