! * SCREEN TO BLACK, RANDOMIZE , MAGNIFYx3 SPRITES
10 CALL SCREEN(2)::CALL CLEAR::RANDOMIZE::CALL MAGNIFY(3)

! * ARRAY FOR THE STAR CHARACTER NUMBERS
15 DIM S(15)::FOR A=1 TO 15::READ S(A)::NEXT A
16 DATA 64,68,72,76,80,84,88,92,96,100,104,108,112,116,120

! * SPACE SHIP AND MISSILE
20 CALL CHAR(36,"000000C0F38430F83EB38F5F0E00000000000000C03048003FEE74A00000000000000000000000002B000000000000000000000000000038FC38000000000000")

! * STARS DEFINITIONS.  
30 A$="00000000000000000000010000000000"
40 CALL CHAR(64,A$,68,A$,72,A$,76,A$,80,A$,84,A$,88,A$,92,A$,96,A$,100,A$,104,A$,108,A$,112,A$,116,A$,120,A$)

! * STAR COLOURS
45 CALL COLOR(5,16,2,6,5,2,7,10,2,8,16,2,9,5,2,10,10,2)
46 CALL COLOR(11,11,2,12,16,2)

! * PLOT OUR STARS TO THE SCREEN RANDOMLY
50 N=64::FOR A=1 TO 24
60 Y1=INT(32*RND)+1::Y2=INT(32*RND)+1::IF Y1=Y2 THEN 60
70 CALL HPUT(A,Y1,CHR$(N))::N=N+4::IF N>120 THEN N=64
80 CALL HPUT(A,Y2,CHR$(N))::NEXT A

! * PLACE THE SPACE SHIP SPRITE
90 CALL SPRITE(#1,36,4,72,16)::F=0::T=0::TM=4


! * MAIN LOOP
1000 GOSUB 2100::GOSUB 2200::GOSUB 2400::GOSUB 2300::GOSUB 2400::GOTO 1000




! * NOW START TWINKLING THOSE STARS RANDOMLY
2100 T=INT(15*RND)+1 :: CALL SWAPCHAR(S(T),S(T)+1)::RETURN

! * JOYSTICK MOTION AND FIRING
2200 CALL JOYMOTION(1,X,Y,#1,24,16,K) :: IF K<>18 THEN 2299
2205 IF F=1 THEN 2299 ELSE F=1::CALL POSITION(#1,P1,P2)::CALL SPRITE(#2,40,12,P1,P2,0,20)
2299 RETURN

! * ROLL SCREEN (NOT RECOMMENDED IF SCORE IS BEING DISPLAYED!)
2300 T=T+1 :: IF T>(TM-F) THEN 2305 ELSE 2399
2305 T=0::CALL ROLLLEFT
2399 RETURN


! * CHECK PLAYER MISSILE POSITION IF ACTIVE.....
2400 IF F=1 THEN 2405 ELSE 2499
2405 CALL POSITION(#2,P1,P2)::IF P2>240 THEN 2410 ELSE 2499
2410 CALL DELSPRITE(#2)::F=0
2499 RETURN