MGCML.MAC=MGCML.MAC
-51,,/;PE/
;		MODIFIED FOR FILEIND BY PAUL ELLIOTT NOV 78.
-64,,/;PE/
	.MCALL	OFNB$W
-77,,/;PE/
	.MCALL	OPEN$R
-301,,/;PE/
	CALL EXTOP	;OPEN AN SECOND CONTROL FILE IF NEEDED
	BCS	4$	;CHECK FOR ERROR ON SECOND FILE
-338,,/;PE/
	CALL	EXTOP	;OPEN SECOND FILE IF SPECIFIED
	BCS	OPRERR	;CHECK FOR ERROR
-365,369,/;PE/
	CSI$2	R0,OUTPUT,#$SWTAB ; GET THE OUTPUT FILE				;PW001
	BCS	10$								;PW001
	BITB	#CS.WLD,C.STAT(R0) ; NO * WILD CARDS, AND ONLY ONE FILE	;PW001
-380,,/;PE/
	MOV	R0,-(SP)	;SAVE R0
	MOVB	EXST,R0		;GET FLAG FOR EXTRA FILE
	BGE	5$		;TEST IF EXTRA FILE IF N COMPLEMENT
	NEGB	R0
5$:	CMPB	R0,G.CDEP(R5)	;CHECK IF AT SAME LEVEL AS
	BNE	6$		;WHEN EXTRA FILE WAS OPENED
	CLOSE$	#EXTRA,7$	;IF Y THEN CLOSE IT.
	CLRB	EXST		;SET FLAG EXTRA FILE NOT IN USE
6$:	MOV	(SP)+,R0	;RESTORE R0
-422,,/;PE/
7$:	RETURN	;RESTORE REGS
-506,506,/;PE/
GOPEN:	TSTB	EXST+1	;TO OPEN EXTRA FILE MUST SKIP THIS
	BLT	2$	;MYSTERYOUS CODE
			;I DO NOT NO WHY OR WHAT THIS CODE DOES.
	MOV	R5,R0		;++002 PUT FDB ADDR IN R0
-517,517,/;PE/
2$:	MOV	R0,R1		; POINT R1 TO THE
-522,525,/;PE/
			;I DO NOT KNOW WHY THE CODE
			;FROM AAA TO BBB IS NECESSARY BUT IT IS
			; IF IT IS NOT THERE WE FAIL TO OPEN
			;THE FILE FOR READ WITH CODE .NSF=-26
			;(NO SUCH FILE) THIS IS BECAUSE N.DID
			;HAS THE ID OF [0,0] INSTEAD OF THE
			;THE USER DIRECTORY WHY THIS IS I
			;DO NOT UNDERSTAND.  PERHAPS IT IS A
			;BUG IN THE .PARSE ROUTINE OR
			;PERHAPS THIS PROGRAM CHANGED SOME
			;GLOBAL FCS INFO THAT MADE .PARSE
			;BEHAVE IN THIS MANNER
			;IN ANY CASE THE CALLS TO GETDID
			;AND GETDIR CAUSE THE DOUBLY
			;DEFINED SYMBOLS.
;AAA
	TSTB	EXST+1		;CHECK IF READING EXTRA FILE
	BGT	20$		;+ THEN OPEN FOR WRITE
	BEQ	23$		;0 THEN MCR FILE SKIP OPEN READ
	ADD	#4,R2		;GET DIRECTORY STRING
	TST	(R2)		;IS THERE A DIRECTORY?
	BNE	22$		;YES USE GETDI
	CALL	.GTDID		;OTHERWISE USE DEFAULT STRING
	BCS	10$		;CHECK FOR ERRORS
	BR	23$		;OPEN FOR READ
22$:	CALL	.GTDIR		;GET THE USER SPECIFIED DIRECTORY
	BCS	10$		;CHECK FOR ERROR
;BBB
23$:	OFNB$R
10$:	RETURN			;++002
20$:	OFNB$W		;OPEN FOR WRITE
	RETURN


EXTOP:	TSTB	EXST		;CHECK IF FILE ALREADY IN USE
	BEQ	5$		;NO
	RETURN		;RETURN IF ALREADY IN USE
5$:	CALL	$SAVAL		;SAVE ALL REGISTERS
	MOV	#$CSIBK,R0	;GET CSI CONTROL
	BITB	#CS.MOR,C.STAT(R0)	;CHECK IF , OCCURS
	BEQ	20$		;NO CHECK FOR OUTPUT FILE
	BITB	#CS.EQU,C.STAT(R0)	;CHECK FOR INPUT FILE
	BNE	21$		;NO SIMPLY RETURN
	CSI$2	R0,OUTPUT	;GET FILE INFO
	BCS	21$		;ERROR
	FDOP$R	#EXTRA,,,,FO.WRT	;SET FILE OUTPUT
	MOVB	#1,EXST+1	;SET FLAG FOR EXTRA OUTPUT
	MOV	R5,-(SP)	;SAVE R5
	MOV	R0,R5		;OPEN REQUIRES FDB IN R5
	CALL	OPEN		;OPEN THE FILE
	MOV	(SP)+,R5	;RESTORE R5
	BCS	21$		;ERROR
	CLRB	EXST+1		;CLEAR FLAG FOR EXTRA FILE
	MOVB	G.CDEP(R5),EXST	;SAVE THE DEPTH AT WHICH OPEN OCCURED
	NEGB	EXST		;- MEANS OUTPUT
10$:	CLC			;OK
	RETURN
20$:	BITB	#CS.EQU,C.STAT(R0)	;CHECK IF = OCCURED
	BEQ	10$			;NO RETURN
	CSI$2	R0,INPUT		;GET FILE INFO
	BCS	21$			;ERROR
	MOV	#EXTRA,R0		;GET FILE FDB
	FDOP$R	R0,,,,FO.RD		;SET FILE FOR READ
	MOVB	#-1,EXST+1		;SET EXTRA READ FLAG
	MOV	R5,-(SP)		;SAVE R5
	MOV	R0,R5		;REQUIRES R5 TO BE FDB
	CALL	OPEN		;OPEN THE FILE
	MOV	(SP)+,R5	;RESTORE R5
	BCS	21$		;CHECK ERROR
	CLRB	EXST+1		;CLEAR EXTRA FLAG
	MOVB	G.CDEP(R5),EXST	;SAVE DEPTH AT WHICH THIS OPEN OCCURED
	BR	10$		;RETURN
21$:	CLRB	EXST+1		;ERROR RETURN
	SEC			;SET ERROR BIT
	RETURN
/