00100		SUBROUTINE INVIS(MA,MB,MC,MD,N)
00110		DIMENSION LL(100)
00200		COMMON/PLT/JX,JY,JPL,PLT,REV,RINV,ROT,RLR,RUD,CONST,E
00300		1 ,JREV,JINV,KA,KB,KC,KD,RTO,JA,JB,JAR,JBR,A,IA,IB,IC,ID
00400		CALL JZERO
00500		NA=MA/3
00600		NB=MB/3
00700		NC=MC/3
00800		ND=MD/3
00850		IF(N.EQ.0)N=-1
00900		IF(N)CALL DPYSET(2,LL,100)
00950		N=1
01000		CALL JZERO
01100		CALL DPYBRT(2)
01200	1	CALL AIVECT(-380,-200)
01300		JA=NA
01400		JB=NC
01500		CALL LINES(3)
01600		JB=NC
01700		JA=NB
01800		CALL LINES(2)
01900		JB=ND
02000		JA=NB
02100		CALL LINES(2)
02200		JA=NA
02300		JB=ND
02400		CALL LINES(2)
02500		JA=NA
02600		JB=NC
02700		CALL LINES(2)
02800		CALL JZERO
02900	6683	CALL DPYOUT(2)
03000		END