.TITLE	CVL - CHANGE VOLUME LABEL
	.IDENT	/01.00/
	.LIST	MEB
;
; AUTHOR:	H. L. COLEMAN
;		MILLIKEN AND COMPANY
;		P. O. BOX 1926
;		MAIL STOP M-103
;		SPARTANBURG, S. C. 29304
;		(803)573-2556
;
; DATE:		24-JAN-78
;
; MODIFIED:
;
; FUNCTION:	READ THE DISK LABEL BLOCK AND CHANGE THE LABEL TO THAT
;		SPECIFIED IN THE MCR COMMAND.  IF NO MCR COMMMAND IS
;		AVAILABLE, THE OPERATOR IS PROMPTED FOR COMMANDS.
;
; INPUT:
;
;		MCR COMMAND OF THE FORM:
;
;			CVL DDU:LABEL
;
; OUTPUT:
;
;		THE SPECIFIED DISK LABEL BLOCK IS MODIFIED.
;
	.PAGE
	.MCALL	QIOW$S,WSIG$S,GMCR$,EXIT$S,DIR$
	.MCALL	MSGN$S
	.MCALL	ALUN$S
	.MCALL	TCBDF$,LCBDF$,DCBDF$,UCBDF$,HMBOF$
	TCBDF$	<:>,<=>		;DEFINE TCB OFFSETS
	UCBDF$	<:>,<=>		;DEFINE UCB OFFSETS
	DCBDF$	<:>,<=>		;DEFINE DCB OFFSETS
	LCBDF$	<:>,<=>		;DEFINE LCB OFFSETS
	HMBOF$			;DEFINE HOME BLOCK OFFSETS
	.PSECT	CVL
	.PAGE
; MESSAGES - ERROR AND OTHERWISE
;
; ALL MESSAGES PRINTED BY MSGTRP UTILITY ROUTINE
;
PFX:	.BYTE	PRMT-PFX-1	;MESSAGE PREFIX
	.ASCII	/CVL -/
PRMT:	.BYTE	M001-PRMT-1		;PROMPT PREFIX
	.ASCII	/CVL>/
M001:	.BYTE	M002-M001-1
	.ASCII	/PRIVLEDGE VIOLATION/
M002:	.BYTE	M003-M002-1
	.ASCII	/SYNTAX ERROR/
M003:	.BYTE	M004-M003-1
	.ASCII	/INVALID DEVICE/
M004:	.BYTE	M005-M004-1
	.ASCII	/DEVICE NOT MOUNTED/
M005:	.BYTE	M006-M005-1
	.ASCII	/HEADER BLOCK READ ERROR /
HBREC:	.ASCII	/       /
M006:	.BYTE	M007-M006-1
	.ASCII	/HEADER BLOCK WRITE ERROR /
HBWEC:	.ASCII	/       /
M007:	.BYTE	M008-M007-1
	.ASCII	/VOLUME NAME CHANGED FROM /
OLDLBL:	.ASCII	/            /
	.ASCII	/ TO /
NEWLBL:	.ASCII	/            /
M008:	.BYTE	0
	.EVEN
	.PAGE
; CONSTANTS AND WORK AREAS.
;
MCRLIN:	GMCR$			;MCR COMMAND BUFFER
	.WORD	0		;BUFFER PAD
DEV:	.ASCII	/  /		;DEVICE NAME
UNIT:	.WORD	0		;UNIT NUMBER
IOSB:	.WORD	0,0		;IOSB FOR DISK I/O
PRFLG:	.WORD	0		;PROMPT MODE FLAG
LBN:	.WORD	0,0		;DISK LOGICAL BLOCK NUMBER
HDRBUF:	.BLKW	256.		;DISK HEADER BUFFER
	.PAGE
CVL::	MOV	$TKTCB,R1	;R1 = A(MY TCB)
	MOV	T.UCB(R1),R0	;R0 = A(TI: UCB)
	BIT	#U2.PRV,U.CW2(R0) ;IS USER PRIVLEDGED?
	BNE	1100$		;IF NE, YES - CONTINUE
	MSGN$S	PFX,3,M001,,,ABORT ;PRIVLEDGE VIOLATION!
1000$:	EXIT$S			;EXIT
1100$:	DIR$	#MCRLIN		;GET MCR COMMAND LINE
	BCC	1300$		;IF CC, GOT ONE - GO PROCESS IT
1200$:	MOV	#1,PRFLG	;INDICATE PROMPT MODE
	MOV	#"CV,MCRLIN+2	;MAKE IT LOOK LIKE MCR COMMAND
	MOV	#"L ,MCRLIN+4
	MSGN$S	PRMT,0,,MCRLIN+6,74.,ABORT ;PROMPT
	CMPB	#IE.EOF,$TIOSB	;CTRL/Z?
	BEQ	1000$		;IF EQ, YES - EXIT
	MOV	$TIOSB+2,R0	;GET LENGTH READ
	BEQ	1200$		;IF EQ, NO DATA READ - PROMPT AGAIN
	ADD	#MCRLIN+6,R0	;R0 = A(EOL)
	CLRB	(R0)		;TERMINATE INPUT LINE
1300$:	MOV	#MCRLIN+2,R1	;R1 = A(COMMAND)
	CLR	LBN		;SET BEGINNING LBN
	MOV	#1,LBN+2
	MOV	#NEWLBL+12.,R4	;R4 = A(END OF NEW NAME FIELD)
	MOV	#12.,R0		;R0 = COUNT
1350$:	CLRB	-(R4)		;CLEAR AREA
	SOB	R0,1350$	;LOOP UNTIL DONE
				;R4 = A(NEW NAME AREA)
	CLR	R3		;R3 = 0
1400$:	CALL	GETNXT		;GET NEXT CHARACTER IN BUFFER
	BCS	1600$		;IF CS, EOL - SYNTAX ERROR
	BVC	1400$		;IF VC, NO BLANK SEEN - KEEP LOOKING
	MOV	R1,R2		;R2 = A(NEXT CHARACTER)
	DEC	R2		;R2 = A(DEVICE SPECIFIER)
1500$:	CMPB	#':,R0		;COLON?
	BNE	1700$		;IF NE, NO - CHECK FURTHER
	TST	R3		;COLON ALREADY SEEN?
	BNE	1600$		;IF NE, YES - SYNTAX ERROR
	MOV	R1,R3		;R3 = A(LABEL FIELD)
	BR	1800$		;KEEP SCANNING
1600$:	MSGN$S	PFX,3,M002,,,ABORT ;SYNTAX ERROR
	BR	1200$		;FORCE PROMPT MODE
1700$:	TST	R3		;COLON ALREADY SEEN?
	BEQ	1800$		;IF EQ, NO - KEEP SCANNING
	CMP	R4,#NEWLBL+12.	;LABEL TOO LONG?
	BHIS	1600$		;IF LOS, YES - SYNTAX ERROR
	MOVB	R0,(R4)+	;PUT CHARACTER IN LABEL AREA
1800$:	CALL	GETNXT		;GET NEXT CHARACTER FROM BUFFER
	BCC	1500$		;IF CC, GOT ONE - KEEP SCANNING
	MOV	R2,R0		;R0 = A(DEVICE SPECIFIER)
	MOV	#DEV,R3		;R3 = A(DEVICE ID BUFFER)
	CALL	$FDLOG		;PARSE DEVICE (MCR PARSER)
	BCC	2000$		;IF CC, DEVICE OK SO FAR
	TST	R3		;WHAT TYPE OF ERROR WAS IT
	BEQ	1600$		;IF EQ, SYNTAX ERROR
1900$:	MSGN$S	PFX,3,M003,,,ABORT ;INVALID DEVICE
	BR	1200$		;FORCE PROMPT MODE
2000$:	CALL	$SWSTK,2040$	;SWITCH TO SYSTEM STACK
2020$:	MOV	U.RED(R1),R1	;FOLLOW REDIRECT CHAIN
	CMP	U.RED(R1),R1	;END OF CHAIN?
	BNE	2020$		;IF NE, NO - KEEP LOOKING
	MOV	R1,4(SP)	;SET R1 IN SAVED R1 ON STACK
	RETURN			;RETURN TO USER STATE
2040$:	BIT	#DV.F11,U.CW1(R1) ;FILES 11 DEVICE?
	BEQ	1900$		  ;IF EQ, NO - INVALID DEVICE
	BITB	#US.MNT,U.STS(R1) ;IS IT MOUNTED?
	BEQ	2100$		  ;IF EQ, YES - ALL OK
	MSGN$S	PFX,3,M004,,,ABORT ;DEVICE NOT MOUNTED
2080$:	BR	1200$		;FORCE PROMPT MODE
2100$:	ALUN$S	#2,DEV,UNIT	;ASSIGN LUN 2 TO DEVICE
	BCC	2200$		;IF CC, LUN ASSIGNED
	CALL	ABORT		;ABORT TASK
2200$:	QIOW$S	#IO.RLB,#2,#1,,#IOSB,,<#HDRBUF,#512.,,LBN,LBN+2> 
	BCC	2400$		;IF CC, NO DIRECTIVE ERROR - CHECK I/O
	CMP	#IE.UPN,$DSW	;INSUFFICIENT DYNAMIC MEMORY?
	BEQ	2300$		;IF EQ, YES - TRY AGAIN
	CALL	ABORT		;ABORT TASK
2300$:	WSIG$S			;GIVE SYSTEM A CHANCE TO FREESOME DSR
	BR	2200$		;TRY AGAIN
2400$:	CMPB	#IS.SUC,IOSB	;READ SUCESSFULL?
	BEQ	2500$		;IF EQ, YES - GO CHANGE LABEL
	MOV	#HBREC,R0	;R0 = A(ERROR CODE FIELD)
	MOV	IOSB,R1		;R1 = ERROR CODE
	MOV	R0,R2		;NO ZERO SUPRESSION
	CALL	$CBOMG		;INSERT ERROR CODE IN MESSAGE
	MSGN$S	PFX,3,M005,,,ABORT ;HEADER BLOCK READ ERROR
	BR	2080$		;FORCE PROMPT MODE
2500$:	MOV	#HDRBUF,R0	;R0 = A(HEADER BUFFER)
	MOV	#H.CHK1/2,R1	;R1 = COUNT OF WORDS TO CHECKSUM
	CALL	CHKSUM		;COMPUTE CHECKSUM
	CMP	R1,(R0)		;DOES IT MATCH HOME BLOCK?
	BNE	2520$		;IF NE, NO - MUST NOT BE HOME BLOCK
	MOV	#HDRBUF,R0	;R0 = A(HOME BLOCK)
	MOV	#H.CHK2/2,R1	;R1 = COUNT OF WORDS TO CHECKSUM
	CALL	CHKSUM		;COMPUTE CHECKSUM
	CMP	R1,(R0)		;DOES IT MATCH HOME BLOCK?
	BEQ	2540$		;IF EQ, YES - THIS MUST BE HOME BLOCK
2520$:	BIC	#377,LBN+2	;MAKE MULTIPLE OF 256.
	ADD	#256.,LBN+2	;BUMP TO NEXT MULTIPLE OF 256.
	ADC	LBN		;DOUBLE PRECISION
	BR	2200$		;TRY AGAIN
2540$:	MOV	#HDRBUF+H.VNAM,R0 ;R0 = A(VOLUME NAME)
	MOV	#NEWLBL,R1	;R1 = A(NEW NAME)
	MOV	#OLDLBL,R2	;R2 = A(OLD NAME FIELD)
	MOV	#12.,R3		;R3 = COUNT
2600$:	MOVB	(R0),(R2)+	;COPY OLD NAME
	MOVB	(R1)+,(R0)+	;INSERT NEW NAME
	SOB	R3,2600$	;LOOP UNTIL DONE
	MOV	#HDRBUF,R0	;R0 = A(HOME BLOCK)
	MOV	#H.CHK1/2,R1	;R1 = COUNT OF WORDS TO CHECKSUM
	CALL 	CHKSUM		;COMPUTE CHECKSUM
	MOV	R1,(R0)		;SET NEW CHECKSUM
	MOV	#HDRBUF,R0	;R0 = A(HOME BLOCK)
	MOV	#H.CHK2/2,R1	;R1 = COUNT OF WORDS TO CHECKSUM
	CALL	CHKSUM		;COMPUTE CHECKSUM
	MOV	R1,(R0)		;SET NEW CHECKSUM
2700$:	QIOW$S	#IO.WLB,#2,#1,,#IOSB,,<#HDRBUF,#512.,,LBN,LBN+2> 
	BCC	2900$		;IF CC, NO DIRECTIVE ERROR
	CMP	#IE.UPN,$DSW	;INSUFFICIENT DYNAMIC MEMORY?
	BEQ	2800$		;IF EQ, YES - TRY AGAIN
	CALL	ABORT		;ABORT TASK
2800$:	WSIG$S			;GIVE SYSTEM A CHANCE TO FREE SOME DSR
	BR	2700$		;GO TRY AGAIN
2900$:	CMPB	#IS.SUC,IOSB	;WRITE SUCESSFULL?
	BEQ	3000$		;IF EQ, YES - GO SEE IF MORE TO DO
	MOV	#HBWEC,R0	;R0 = A(ERROR CODE FIELD)
	MOV	IOSB,R1		;R1 = ERROR CODE
	MOV	R0,R2		;NO ZERO SUPRESSION
	CALL	$CBOMG		;INSERT ERROR CODE
	MSGN$S	PFX,3,M006,,,ABORT ;HEADER BLOCK WRITE ERROR
2950$:	JMP	1200$		;FORCE PROMPT MODE
3000$:	MSGN$S	PFX,0,M007,,,ABORT ;VOLUME NAME CHANGED FROM - TO
	TST	PRFLG		;PROMPT MODE?
	BNE	2950$		;IF NE, YES - GO PROMPT AGAIN
	EXIT$S			;EXIT
ABORT:	HALT			;ABORT TASK
	.PAGE
; GETNXT
;
; FUNCTION:	SUBROUTINE TO GET NEXT NON-BLANK CHARACTER FROM THE
;		MCR COMMAND BUFFER.
;
; INPUT:
;
;	R1 = A(NEXT CHARACTER TO SCAN)
;
; OUTPUT:
;
;	R0 = NEXT NON-BLANK CHARACTER
;	R1 = A(NEXT CHARACTER TO SCAN)
;	CC - R0 CONTAINS CHARACTER
;	CS - END OF LINE REACHED
;	VC - NO BLANKS SKIPPED
;	VS - AT LEAST ONE BLANK SKIPPED
;
GETNXT:	CLR	-(SP)		;CLEAR BLANK COUNT
1000$:	MOVB	(R1)+,R0	;R0 = NEXT CHARACTER
	BEQ	1300$		;IF EQ, EOL - GO SET CARRY
	CMPB	#' ,R0		;IS IT A BLANK?
	BNE	1100$		;IF NE, NO - CHECK FURTHER
	INC	(SP)		;BUMP BLANK COUNT
	BR	1000$		;GO GET NEXT CHARACTER
1100$:	CMPB	#15,R0		;CARRIAGE RETURN?
	BEQ	1300$		;IF EQ, YES - GO SET CARRY
	CMPB	#33,R0		;ESCAPE?
	BEQ	1300$		;IF EQ, YES - GO SET CARRY
	CMPB	#' ,R0		;LEGAL CHARACTER?
	BHI	1000$		;IF HI, NO - GO GET ANOTHER ONE
	CMPB	#172,R0		;LEGAL CHARACTER?
	BLO	1000$		;IF LO, NO - GO GET ANOTHER ONE
1200$:	TST	(SP)+		;DID WE SEE A BLANK
	BEQ	1250$		;IF EQ, NO - LEAVE VC
	SEV			;SET OVERFLOW
1250$:	RTS	PC		;RETURN TO CALLER
1300$:	TST	(SP)+		;DID WE SEE ANY BLANKS?
	BEQ	1400$		;IF EQ, NO - LEAVE VC
	SEV			;SET OVERFLOW
1400$:	SEC			;SET CARRY
	RTS	PC		;RETURN TO CALLER
	.PAGE
; CHKSUM
;
; FUNCTION:		SUBROUTINE TO FORM A CHECKSUM OF A VARIABLE NUMBER OF
;			WORDS.  THE CHECKSUM IS COMPATIABLE WITH THAT USED IN
;			FILES 11 HOME BLOCKS.
;
; INPUT:
;
;	R0 = A(AREA TO CHECKSUM)
;
;	R1 = COUNT OF WORDS TO CHECKSUM
;
; OUTPUT:
;
;	R0 = A(NEXT WORD AFTER AREA CHECKSUMMED)
;
;	R1 = COMPUTED CHECKSUM
;
CHKSUM:	CLR	-(SP)		;INITILIZE CHECKSUM
1000$:	ADD	(R0)+,(SP)	;ADD NEXT WORD
	SOB	R1,1000$	;LOOP UNTIL DONE
	MOV	(SP)+,R1	;R1 = COMPUTED CHECKSUM
	RETURN			;RETURN TO CALLER
	.END	CVL