SUBROUTINE BOMB(MY2,INVDER,INVPOS,IFIRE,JX
	+,MX,MISS,IHARD,SH,IGOES)
	INTEGER INVDER(5,20),INVPOS(5,20,2),BOMPOS(10,2)
	INTEGER BOMBS(10),MY2(20),SH(5,4)
	COMMON /BLK1/BOMBS,BOMPOS,I1,I2
	COMMON /BLK3/ISTAT
C
C  See if any bombs to be dropped
C
D	TYPE *,'  BOMB'
	DO 30 I=1,20
	IF (INVDER(MY2(I),I).EQ.0) GOTO 30	!This Invader is dead
	N=0					!Clear flag
	DO 10 J=1,IHARD				!No.of bombs allowed
	IF (BOMBS(J).NE.0) GOTO 10		!See if a bomb can go
	IF (N.NE.0) GOTO 10			!already set one off
	N=J				!get No. of bomb to be dropped
10	CONTINUE
	IF (N.EQ.0) GOTO 30		!No spare Bombs
20	IF (RAN(I1,I2).GE.0.99) GOTO 25	!Only fire 1% of time
	STL=ABS(INVPOS(MY2(I),1,1)+2-JX)
	IF (STL.LE.5..AND.RAN(I3,I4).GE.0.98) GOTO 25
	GOTO 30
25	I1=I1+JX			!Keep random patern
	I2=I2+MISS			!Random
	BOMPOS(N,1)=INVPOS(MY2(I),I,1)+2	!Get position for bomb
	BOMPOS(N,2)=INVPOS(MY2(I),I,2)
	BOMBS(N)=-1			!Say the bomb is gone
30	CONTINUE
C
C  See which bombs are falling and move them
C
	DO 50 I=1,IHARD			!Max No.of bombs allowed
	IF (BOMBS(I).EQ.0) GOTO 50	!This one is not released
	NX=BOMPOS(I,1)			!get the position of bomb
	NY=BOMPOS(I,2)
	IF (NX.GT.76) GOTO 45		!Can't drop them outside here
	IF (NX.LT.4) GOTO 45
	IF (BOMBS(I).EQ.-1) GOTO 33	!Just released
	CALL POSITN(NX,NY)		!Rub out old bomb
	WRITE(5,70)
33	NY=NY-1				!Move bomb down 1
	IF (NY.EQ.1) GOTO 40		!See if it has hit base
	IF (NY.EQ.2) GOTO 100		!see if it has hit shelter
	CALL POSITN(NX,NY)		!Draw bomb
	WRITE(5,60)
	BOMBS(I)=1			!Say it is dropping
	IF (IFIRE.EQ.0) GOTO 47		!see if missile is in flight
	IF (NX.NE.MX) GOTO 47		!& in same column
	IF (NY.EQ.MISS) GOTO 35		!& same row
	IF (NY.NE.MISS-1) GOTO 11
	CALL POSITN(MX,MISS+1)
	WRITE(5,12)
12	FORMAT('$ ')
	GOTO 35
11	IF (NY-MISS.NE.1) GOTO 47	!or just below
35	IFIRE=0				!If above satisfied
	MISS=0				!bomb is distroyed
	CALL EXPLOD(NX,NY)		!blow it up
	GOTO 45				!Switch off bomb
40	IF (NX.EQ.JX) GOTO 43		!See if we hit base
	IF (NX.EQ.JX-1) GOTO 43
	IF (NX.EQ.JX+1) GOTO 43
	GOTO 45				!No , Failure
43	CALL DEAD(JX)			!Bang another life gone
	CALL SHLTER(SH,SH,1)
	IGOES=IGOES+1
	IF (IGOES.LT.4) GOTO 45		!Still got some time left
	JI=IPOKE("44,ISTAT)
	CALL EXIT			!Bye : That's your lot
100	DO 110 IS1=1,5			!See if we hit a shelter
	DO 110 IS2=1,4
	IF (SH(IS1,IS2).EQ.0) GOTO 110	!See if it's gone
	IS3=(13*IS1)+IS2		!No, get it's position
	IF (IS3.NE.NX) GOTO 110		!Do we hit it
	SH(IS1,IS2)=SH(IS1,IS2)-1	!Yes , Down it goes
	GOTO 45
110	CONTINUE
	GOTO 47
45	NX=0				!Bomb does not exist anymore
	NY=0
	BOMBS(I)=0
47	BOMPOS(I,1)=NX			!Stores Current position
	BOMPOS(I,2)=NY
50	CONTINUE
	RETURN
C
C  Format to Draw bomb
C
60	FORMAT('$v')
70	FORMAT('$ ')
	END