COMPIL(USC,<USERCON>,<SAVE,RESTR,GOGTAB>,<USERCON ROUTINE>)
CMU <
GGAS <
IFE ALWAYS, <EXTERNAL GLUSER>
>;GGAS
>;CMU
HERE(USERCON)
	PUSHJ	P,SAVE
	MOVE	LPSA,[XWD 4,4]
	MOVE	A,-1(P)		;THE FLAG
CMU < GGGON
>;CMU
GLOB <
	MOVEI	B,ENDREN
	JUMPL	A,[MOVEI USER,GLUSER
		   MOVEI B,ZAPEND ;USE GLOBAL TABLE
		   JRST .+1]
	SKIPL	C,-3(P)		;THE INDEX
	CAML	C,B
>;GLOB
NOGLOB <
	SKIPL	C,-3(P)		;THE INDEX
	CAIL	C,ENDREN	;CHECK BOUNDS
>;NOGLOB
	ERR	<USERCON: index out of bounds >,7,RESTR
	ADD	C,USER		;POINT AT CORRECT ENTRY
	MOVE	B,(C)		;GET OLD VALUE
	MOVE	D,@-2(P)	;(PERHAPS) NEW VALUE
	TRNE	A,1		;STORE NEW VALUE?
	MOVEM	D,(C)		;YES
	MOVEM	B,@-2(P)	;RETURN OLD VALUE
GLOB <
	MOVE	USER,GOGTAB	;RESET
>;GLOB
	JRST	RESTR
CMU < GGGOFF
>;CMU
ENDCOM(USC)