.TITLE BFDEFS
.LIST TTM
	; BIO DATABASE FILE ROOT OFSETS
	;
RT.SIZE==0
RT.AGE==2		;FILE AGE
RT.BIAS==4		;FILE AGE BIAS
RT.KEY==6		;POINTER TO FIRST KEY
RT.FREE==10		;POINTER TO FIRST FREE BLOCK
RT.NLV==12		;NUMBER OF LEVELS IN THIS FILE
RT.FDB==14		;ADDRESS OF FILE'S FDB
RT.LEV==16		;CURRENT ACTIVE LEVEL NUMBER
RT.BUF==20		;POINTER TO CURRENT ACTIVE BUFFER
RT.PCL==22		;POINTER TO CURRENT ACTIVE LEVEL TABLE
RT.LLA==24		;POINTER TO LAST LEGAL ADDRESS OF CURRENT BLOCK
RT.DTY==26		;DATA TYPE
RT.VER==30		;STRUCTURE VERSION NUMBER. 
	;
LV.1ST==506.		;ROOT BLOCK OFFSET TO FIRST LEVEL TABLE.
	;
	; FAKE LEVEL TABLE TO MAKE THE ROOT BLOCK LOOK LIKE A KEY BLOCK
	;
RT.LEN==LV.1ST-0		;LENTH OF A KEY(MUST BE 4 IN THE ROOT BLOCK)
RT.SCN==LV.1ST-2		;SIZE OF RETRIVAL SECTION OF KEY
RT.LLK==LV.1ST-4		;OFFSET TO LAST LEGAL KEY IN BLOCK
RT.PCB==LV.1ST-6		;POINTER TO CURRENT BLOCK
RT.PCE==LV.1ST-10		;POINTER TO CURRENT ELEMENT
RT.FLG==LV.1ST-12		;FLAG WORD FOR THE ROOT AND FILE AS A WHOLE
	;
	;LEVEL TABLE OFFSETS
	;
LV.LEN==0		;LENTH OF A KEY IN THIS LEVEL
LV.SCN==-2		;SCAN SIZE OF KEY
LV.LLK==-4
LV.PCB==-6		;Pointer to Current Block
LV.PCE==-8.		;Pointer to Current Element in key block
LV.FLG==-10.		;FLAG WORD FOR THIS LEVEL
LV.SIZE==-12.		;SIZE OF A LEVEL TABLE IN BYTES
	;
	;BIT MASKS FOR FLAG WORDS
	;
FL.INT==1		;DATA SECTION CONTAINS INTEGERS
FL.FLT==2		;DATA SECTION CONTAINS REALS
FL.ASC==4		;DATA SECTION CONNTAINS ASCII DATA
FL.WRT==10		;FILE IS OPENED FOR WRITE ACCESS
FL.FKY==20		;BIT MASK FOR KEYS FOUND THIS SEARCH
FL.MOD==40		;BIT MASK FOR CURENT BLOCK MODIFIED
FL.ACT==100		;BIT  FOR INDICATING ACTIVE LEVEL
FL.COR==200		;FILE MAY BE CORRUPTED
	;
	;DATA BLOCK OFSETS
	;
DB.SIZE==512.		;SIZE OF A DATA BLOCK
DB.PNB==510.		;POINTER TO NEXT BLOCK
DB.BLT==508.		;BLOCK TYPE WORD 'RT'==ROOT  'DB'==DATA  'FR'==FREE BLOCK
DB.LLA==506.		;LAST LEGAL ADDRESS FOR ELEMENTS IN BLOCK
		;
		;ERROR RETURN CODES
		;
ER.NRB==-100.		;NOT A ROOT BLOCK
ER.NWA==-99.		;NOT WRITE ACCESSED
ER.FAIL==0		;CAN'T PERFORM OPERATION FOR OTHER REASON THAN ABOVE
ER.NMK==-1		;THERE ARE NO MORE KEYS TO MATCH YOUR PATTERN
.END