*COMDECK,CHN$COM
# 
      CHAIN TABLE - CHN$TABLE 
        USE - CONTAINS AN ENTRY FOR EACH CHAIN WITH THE CHAIN POINTERS, 
              DATA ABOUT OVERLAY ASSOCIAGED WITH THE CHAIN. 
        SIZE - FOUR WORDS PER ENTRY 
# 
# 
        NOTE - THIS COMMON BLOCK IS USED BY REMOVE COMPASS ROUTINE. ANY 
               CHANGES TO THIS BLOCK WILL AFFECT THE CODE IN REMOVE 
# 
      COMMON CHN$COM; 
      BEGIN 
      ARRAY CHN$TABLE [1:CHAINS"BACKGROUND"] S(2);
        ITEM
            CHN$PRIMARY      U (0,0,6),    #PRIMARY OVERLAY LEVEL      #
            CHN$SECOND       U (0,6,6),    #SECONDARY OVERLAY LEVEL    #
            CHN$OVLIN        B (0,12,1),   #OVERLAY IN FLAG            #
            CHN$ENTRYPT      U (0,24,18),  #OVERLAY ENTRY POINT        #
            CHN$NENTRIES     U (0,42,18),  #NUMBER OF ENTRIES ON CHAIN #
            CHN$FIRST        U (1,6,18),   #POINTER TO FIRST CONNECTION#
            CHN$NEXTCHN      U (1,24,18),  #POINTER TO NEXT OVERLAY CHN#
            CHN$LAST         U (1,42,18),  #POINTER TO LAST CONN ON CHN#
            CHN$WORD1        U (1); 
      END 
