! 36	PLAYER SHIP NORMAL
! 40	PLAYER SHIP DOWN
! 44	PLAYER SHIP UP
! 60	PLAYER MISSILE
! 96 	FLYING SAUCER

! R1	CHANGE PATTERN OF FLYING SAUCER


! D1	BACKGROUND SCROLL DELAY TIMER
! D2	BACKGROUND SCROLL MAXIMUM FOR D1 TO INCREMENT TO
!       ** ALTERS FROM 4 (DEFAULT) TO 2 WHEN ENEMIES ARE ON SCREEN

! CO	COUNTER FOR STAR ANIMATIONS
 	


! *********************
! * INITIALIZE SCREEN *
! *********************
100 CALL LINK("SCRN2")::CALL CLEAR::CALL SCREEN(2)::CALL MAGNIFY(3)::RANDOMIZE::CALL LINK("CHSETL")
105 CALL LINK("WINDOW",18,1,19,32)
106 DIM S(30),SX(30),SY(30)


! ***************************
! * PLAYER SHIP DEFINITIONS *
! ***************************
110 CALL CHAR(36,"0000C0F38430F83EB38F5F0E00000000000000C03048003FEE74A00000000000")
120 CALL CHAR(40,"000F1CC3EC18C8F84E134F5F1F0E0000000020CE3748040C3FEE74A080000000")
130 CALL CHAR(44,"0E1F1F9FCF1FBFBF1FBF0F120F0000000080A074FECFF0FCFCF3CC2000000000")
140 CALL CHAR(60,"00000000000000570000000000000000000000000000E0F0E000000000000000")




! ******************************************
! * SCROLLING BACKGROUND IMAGE DEFINITIONS * 
! ******************************************
! COLOUR 15,4,1,16,4,13,28,13,2
150 a$="02070F0F3F7FFFFF000081CBEFF7F7FB02071FBFBFDFDFEF0000C0E0E0F8FCFE"
155 CALL LINK("CHAR2",144,A$)
160 A$="00040A11A14222243049860402020101814224281010080410A84484020201000000000000000000"
165 CALL LINK("CHAR2",152,A$,248,"FFFFFFFF00000000")
166 A$="00000001000000000000000200000000000000000000000000000008000000000000001000000000000000200000000000000040000000000000008000000000"
167 CALL LINK("CHAR2",160,A$)

! **********************
! * COLOUR DEFINITIONS *
! **********************
175 CALL LINK("COLOR2",2,16,2,3,16,2,4,16,2,5,16,2,17,16,2)
180 CALL LINK("COLOR2",6,16,2,7,16,2,8,16,2,15,4,2,16,2,4)



! *********************
! * ENEMY SPEED ARRAY *
! *********************
200 DIM ES(8)

! ****************************
! * ENEMY ALIVE STATUS ARRAY *
! ****************************
210 DIM A(8)




! **************
! * TITLE PAGE *
! **************
500 CALL CLEAR :: CALL DELSPRITE(ALL)
 
! ***********************
! * GET GAME BACKGROUND *
! ***********************
600 GOSUB 32100
605 STA=0::PF=0


! *************************
! * INCREMENT STAGE "STA" *
! *************************
700 STA=STA+1 :: IF STA>8 THEN STA=1



! *****************
! * START STAGE 1 *
! *****************
1000 CALL SPRITE(#1,36,16,96,32)::DLY=1::DLT=0::D1=0::D2=4

! ****************
! * STAGE 1 LOOP *
! ****************
1010 GOSUB 32300		! DELAY?
1020 GOSUB 8100		 	! JOYSTICK
1030 GOSUB 8200			! ANIMATE STARS
1040 GOSUB 8300			! SCROLL GROUND
1045 GOSUB 8200			! ANIMATE STARS
1050 GOSUB 8400			! ENEMY ATTRIBUTES
1060 GOTO 1010




! ********************************
! * JOYSTICK CONTROL PLAYER SHIP *
! ********************************
8100 CALL JOYST(1,JY,JX)::CALL MOTION(#1,-JX*4,JY*3)::CALL KEY(1,K,ST)::GOSUB 8120
8101 IF K=18 THEN 8102 ELSE 8105
8102 IF PF=1 THEN 8105 ELSE CALL POSITION(#1,PP1,PP2)::CALL SPRITE(#2,60,12,PP1,PP2,0,40)::PF=1
8105 IF JX=4 THEN CALL PATTERN(#1,44) ELSE IF JX=-4 THEN CALL PATTERN(#1,40) ELSE CALL PATTERN(#1,36)
8110 RETURN

8120 CALL POSITION(#1,P1,P2,#2,P3,P4)::IF PF=1 THEN 8121 ELSE 8122
8121 IF P4>240 THEN CALL DELSPRITE(#2)::PF=0
8122 IF P1<16 THEN CALL LOCATE(#1,24,P2) ELSE IF P1>128 THEN 32200
8123 IF P2<9 THEN CALL LOCATE(#1,P1,16) ELSE IF P2>160 THEN CALL LOCATE(#1,P1,152)
8124 RETURN



! *******************
! * STARS ANIMATION *
! *******************
8200 S(CO)=S(CO)+1
8205 IF S(CO)>167 THEN 8210 ELSE 8220
8210 S(CO)=160::ZZ=SY(CO)::SY(CO)=SY(CO)-1::IF SY(CO)<1 THEN SY(CO)=32
8215 CALL LINK("DISPLY",SX(CO),ZZ," ")::CALL LINK("DISPLY",SX(CO),SY(CO),CHR$(S(CO)))::GOTO 8230
8220 CO=CO+1 :: IF CO>15 THEN CO=1
8225 CALL LINK("DISPLY",SX(CO),SY(CO),CHR$(S(CO)))
8230 return



! *****************
! * SCROLL GROUND *
! *****************
8300 D1=D1+1 :: IF D1>D2 THEN 8310 ELSE 8399
8310 D1=0::CALL LINK("SCPXLF",144,4,1,152,4,2)
8399 RETURN


! ********************
! * ENEMY ATTRIBUTES *
! ********************
8400 IF DLY=1 THEN 8499
8405 ON STA GOSUB 25100
8499 RETURN


! *********************
! * GET FLYING SAUCER *
! *********************
20100 CALL CHAR(96,"00000003041F38FF7C3F000000000000000000C020F804FF02FC000000000000")
20105 R1=1::ES(1)=14::ES(2)=16::ES(3)=18::ES(4)=20
20110 CALL SPRITE(#11,96,6,32,255,0,-ES(1))
20115 CALL SPRITE(#12,96,11,64,1,0,ES(2))
20120 CALL SPRITE(#13,96,14,96,255,0,-ES(3))
20125 CALL SPRITE(#14,96,10,128,1,0,ES(4))
20130 A(1)=1::A(2)=1::A(3)=1::A(4)=1
20135 RETURN



! ********************************
! * CHANGE FLYING SAUCER PATTERN *
! ********************************
25100 R1=R1+1
25105 IF R1>8 THEN R1=1
25110 ON R1 GOTO 25111,25112,25113,25114,25115,25116,25117,25118
25111 A$="00000003041F38FF7C3F000000000000000000C020F804FF02FC000000000000"::GOTO 25120
25112 A$="00000003061F2EFF4F3F000000000000000000C020F804FF02FC000000000000"::GOTO 25120
25113 A$="00000003051F27FF473F000000000000000000C020F804FF82FC000000000000"::GOTO 25120
25114 A$="00000003041F21FF433F000000000000000000C0A0F884FFC2FC000000000000"::GOTO 25120
25115 A$="00000003041F20FF413F000000000000000000C060F8C4FFE2FC000000000000"::GOTO 25120
25116 A$="00000003041F20FF403F000000000000000000C020F864FF72FC000000000000"::GOTO 25120
25117 A$="00000003041F20FF403F000000000000000000C020F834FF1EFC000000000000"::GOTO 25120
25118 A$="00000003041F20FF403F000000000000000000C020F80CFF06FC000000000000"
25120 CALL CHAR(96,A$)::RETURN


! *************************
! * DRAW BACKGROUND IMAGE *
! *************************
32100 CALL CLEAR
32105 CALL DELSPRITE(ALL)
32110 A$=CHR$(144)&CHR$(145)&CHR$(146)&CHR$(147)
32115 A$=RPT$(A$,8)
32120 CALL LINK("DISPLY",18,1,A$)
32125 A$=CHR$(152)&CHR$(153)&CHR$(154)&CHR$(155)
32130 A$=RPT$(A$,8)
32135 CALL LINK("DISPLY",19,1,A$)
32140 CALL HCHAR(20,1,156,32)
32145 CALL LINK("DISPLY",22,1,"SCORE")
32150 CALL LINK("DISPLY",22,21,"TOP")
32155 N=160::CO=1::FOR Q=2 TO 16::Z=INT(32*RND)+1::SX(CO)=Q::SY(CO)=Z::S(Q)=N
32160 CALL LINK("DISPLY",SX(CO),SY(CO),CHR$(N))::N=N+1::IF N>167 THEN N=160
32165 CO=CO+1
32170 NEXT Q
32175 CO=1::RETURN

! *********************
! * CRASH WITH GROUND *
! *********************
32200 STOP


! *********
! * DELAY *
! *********
32300 IF DLY=1 THEN 32305 ELSE 32399
32305 DLT=DLT+1 :: IF DLT>200 THEN 32310 ELSE 32399
32310 DLT=0::DLY=0::ON STA GOTO 32400,32410,32420,32430,32440,32450,32460,32470
32399 RETURN

! *********************
! * INTRODUCE SAUCERS *
! *********************
32400 D2=2::GOSUB 20100::GOTO 32499

! *
32410 STOP
32420 STOP
32430 STOP
32440 STOP
32450 STOP
32460 STOP
32470 STOP

32499 RETURN