      The SSDN for an MADC channel looks like this:


		+---------------------------------------+
		|		    0			|
		+---------------------------------------+
		|	  0	    |	OID = 42 (hex)	|
		+---------------------------------------+
		| MADC number	    |   MADC channel    |
		+---------------------------------------+
		|		    0			|
		+---------------------------------------+


     The MADC channel is a number from 0-63 (decimal).

     The MADC number is taken from the table in the file:

	USR$DISK3:[GLASS.TX]MADCTBL.DAT

     This table has one section for each front end.  You look up the
camac crate address in the table and put the corresponding MADC number
in the SSDN. 
