COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002		MOVEI A,1
C00006 ENDMK
C⊗;
	MOVEI A,1
	MOVEM A,JCNT		;Probably not needed
	SETZB B,G
	MOVE A,ARRLIN		;Set by SETARR to line for action
	ADD A,[440700,,LLDESC]	;Location where text starts
	HRRZM A,JPTR		;Location of source line
	MOVE D,[440700,,BUF]
	MOVEM D,JWPT		;Buffer pointer at start
	MOVE Q,SUBBUF(E)	;Substitution text location
	ADD Q,[440700,,0]
	SETOM BUF
	MOVE T,[BUF,,BUF+1]
	BLT T,BUF+37		;Set up buffer properly
	MOVN B,SRCOFF		;Character position to start deletion
	HRLZS B
	ILDB C,A
	IDPB C,D		;Copy text to deletion point
	AOBJN B,.-2
	HRL B,SRCSIZ(E)
	IBP A			;Index over replaced text
	SUB B,[1,,1]		;Count space saved
	JUMPG B,.-2
	MOVN T,SUBSIZ(E)	;Get size of substitution string
	HRL B,T
	MOVNS T
	ADD T,B
	SUBI T,149		;Test for possible overflow
	JUMPG T,SUBOVE
	ILDB C,Q
	IDPB C,D
	AOBJN B,.-2
	HRL B,T			;This will test for overflow again
	ILDB C,A
	JUMPE C,****
	IDPB C,D
	AOBJN B,.-3
	JRST SUBOVE
****:	IDPB C,D
	TLNE D,760000
	JRST .-2		;Pad out with nulls
;Now we must give up the space originally used by the line
	MOVE A,JPTR			;Location of line
	LDB T,[111100,,1(A)]		;Get 2nd 9 bits from right of 1(A)
	MOVNI T,(T)			;and do 1's complement of T
	ADDM T,CHAR		;add this to # in CHARS or ATTSIZ.
;	SOS @JLPTR(E)			;Subtract 1 from # in LINES or ATTNUM.
	HRRZ C,(A)			;Get line forward pointer
	MOVEM C,JPTR			;and put it in JPTR.
	MOVSI T,JPTR			;with JPTR location in left half
	HLLM T,(C)			;of pointer for line pointed to.
	PUSHJ P,FSGIVE			;Give up storage space.
;Then we create a new line with proper pointers
	ADDI G,2(B)			;Increase G by 2 + # of characters
	ADDM G,CHAR		;Previously debited by the number in original line
	LSH G,11			;Move G to byte position.
	IORI G,(B)			;IOR in the actual char count.
	MOVEI B,-BUF+1+LLDESC(A)	;Number of words.
	PUSHJ P,FSGET			;Get space to store line.
	MOVSI TT,BUF			;Starting location of source
	HRRI TT,LLDESC(A)		;and starting location of destination.
	BLT TT,-2(T)			;and now BLT, ending at location -2(T)
	MOVSI T,TXTCOD			;A fancy way to store 2 in left half!
	HLLM T,-1(A)			;To 1st header word.
	HRRZM G,1(A)			;Char. cnts in right of 3rd header word.
	AOS T,TXTNUM
	MOVEM T,2(A)			;To 4th header word.
	HLRZ T,JLPT
	CAIE T,PAGE
	SKIPGE 1(T)
	TRO F,UPDTXT			;Flag change in first line.
	TRO F,WRITE
	HRLI T,JLPT
	MOVSM T,(A)
	HRRM A,(T)
	HRLZM A,JLPT
	MOVE A,D

SUBOVE:	OUTSTR [ASCIZ /
Substitution will cause line to exceed LINE-BUFFER size.
 Do you want this? (Y or N) /]