210 IFY2=Y1+1THENS2=PEEK(Y2):POKEY2,6:POKEY2-1,5:Z2=Y2-2:Y1=Y2:D=1
 1000 REM SET UP THE SCREEN
 1010 X1=53600:REM X1=WAVES
 1020 FOR I1=X1 TO X1+31
 1030 POKE I1,128
 1040 NEXT I1
 1050 REM
 1100 REM SET UP THE BOAT
 1110 POKE X1,179:POKE X1+1,180 
 1120 X1=X1+1:REM X1 LOC OF BOAT
 1200 REM SET UP THE SUB
 1210 Y1=53810:REM Y1=SUB LOC
 1220 POKE Y1,7:POKE Y1+1,8
 1230 D=-1:MT=10:TP=45
 1240 DIM T(10,2)
 1250 EX=230:REM EXPLOSION GRP.
 1260 MN=13:REM MINE GRAPHIC
 1270 WV=128:REM WAVE GRAPHIC
 1500 REM SET UP SOME MINES
 1510 READ A
 1520 FOR I=1 TO A
 1530 READ A
 1540 POKE A,MN
 1550 NEXT I
 1600 DATA 3,53895,54070,53775
 1999 REM
 2000 REM MOVE AND FIRE SUB
 2010 Z2=57000:Y2=Y1:S1=0:S2=0
 2020 IFPEEK(Z2)=250THENY2=Y2-1
 2030 IFPEEK(Z2)=252THENY2=Y2+1
 2040 IF PEEK(Z2)=222 AND UP=0 THEN Y2=Y2-32
 2050 IF PEEK(Z2)=255 THEN Y2=Y2+32:UP=0
 2060 IF PEEK(Z2)=126 AND P<MT THEN P=P+1:T(P,1)=Y2:T(P,2)=D
 2100 IFY2+1=Y1THENS2=PEEK(Y2):POKEY2,7:POKEY2+1,8:Z2=Y2+2:Y1=Y2:D=-1
 2120 IFZ2<>57000THEN POKEZ2,32 
 2130 IF Y2=Y1 GOTO 2400
 2200 REM SURFACE OR DIVE
 2210 IF D=1 THEN POKE Y1,32:POKE Y1-1,32
 2220 IF D=-1 THEN POKE Y1,32:POKE Y1+1,32
 2230 IF D=1 THEN S1=PEEK(Y2-1):S2=PEEK(Y2)
 2240 IF D=-1THEN S1=PEEK(Y2):S2=PEEK(Y2+1)
 2250 IF D=1 THEN POKE Y2,6:POKE Y2-1,5
 2260 IF D=-1THEN POKE Y2,7:POKE Y2+1,8
 2270 IF S1=WV AND S2=WV THEN UP=1
 2400 REM FILL IN Z2 AREA
 2410 Y1=Y2
 2420 IF S1=MN THEN POKE Y1,EX:GOTO 9000
 2430 IF S2=MN THEN POKE Y1,EX:GOTO 9000
 2500 REM ADVANCE THE TORPEDOES
 2510 FOR I2=1 TO MT
 2520 IF T(I2,1)=0 GOTO 2590
 2530 IF PEEK(T(I2,1))=TP THEN POKE T(I2,1),32
 2540 T(I2,1)=T(I2,1)+T(I2,2)
 2550 IF PEEK(T(I2,1))=32 THEN POKE T(I2,1),TP:GOTO 2590
 2560 POKE T(I2,1),EX:T(I2,1)=0
 2590 NEXT I2
 2999 FOR I=1 TO 20:NEXT I:GOTO 2000
 3000 REM MOVE THE DESTROYER