*20
	08-D1GD
	 
	EXT MEMORY CONTROL
	 
	ST ADD
	LOC 200
	 
	SW SET
	SR8=1 IF PDP-8I
	SW8-0 IF PDP-8 OR 8S
	SR9 10 11 MUST CONT AN OCTAL VAL
	EQUAL TO THE NUM OF EXT MEM FLDS
	AVAILABLE(1 TO 7) NOTE FLD ZERO 
	IS NOT INCLUDED IN THIS VALUE