; áîáìïç’îïö¸µ’ðç³³’øó›; Sneak Attack by David Plotkin››MODULE››BYTE›  ChrBase=756,Max,Bkgrnd=710,›  Fate=53770,Level=[1],CursIn=752,›  Stick=632,Ps,Loud=[0],Indx=[0],›  DownL=[0],DownR=[0],Loud1=[0],›  Snd1=$D208,Snd2=$D20F,Freq=[169],›  Wsync=$D40A,Colbk=$D018,›  Nmien=$D40E,Hard=[15],›  Consol=53279››CARD›  Scrn=88,RamSet,HiMem=$2E5,›  Score=[0],Comp=[300],Sdlst=560,›  Vdslst=512››CARD ARRAY Linept(24)››BYTE ARRAY›  Charset,Chopperstatus(30),›  Chopperx(30),Choppery(30),›  Expx(60),Expy(60),ExpStatus(60),›  TrStatus(30),Trx(30),Try(30),›  MisStatus(30),Misx(30),Misy(30),›  Ll(20),Rr(20),Dlist,›  ShapeTable(0)=›    [254  16 124  71 127  12  62   0›     127   8  62 226 254  24 126   0›      96  96  48  48  24  60 231 255›      24  24  24  24  24  60 231 255›       6   6  12  12  24  60 231 255›     128  85  17  66  24 170  91 131›      60 126 255 255 195  66  36  24›      60  36  24 255  60  24  36 102›       0   0   0   0   0   0   0   0›      60  36  24 255  60  24  36 102›      60  36 219 255  60  24  36 102›      60  60  24  60  60  24  24  28›      60  60  24  60  60  60 102 195]››PROC Download()›;Step back HiMem and move the›;character set into RAM›CARD Index›BYTE Val›  RamSet=(HiMem-$400)&$FC00›  ChrBase=RamSet RSH 8›  HiMem=RamSet›  FOR Index=0 TO 1023 DO›    Val=Peek(57344+Index)›    Poke(RamSet+Index,Val)›  OD›  Charset=RamSet›RETURN››PROC Dlint()›;the display list interrupt routine›  [$48 $8A $48 $98 $48]›  Wsync=1›  Colbk=50›  [$68 $A8 $68 $AA $68 $40]››PROC Scoreline()›;set up the dli›  Dlist=Sdlst›  Vdslst=Dlint›  Dlist(27)=130›  Nmien=$C0›RETURN››PROC Update()›;print score and level›  Position(1,23)›  Print("Score: ")›  Position(8,23)›  PrintC(Score)›  Position(18,23)›  Print("Level: ")›  Position(25,23)›  PrintB(Level)›RETURN››PROC Title()›BYTE colpf0=53270,colpf1=53271,›     colpf2=53273,colpf3=53273,›     rtclock=20,vcount=54283›  Graphics(18)›  Position(3,4)›  PrintD(6,"SNEAK ATTACK")›  Position(8,5)›  PrintD(6,"BY")›  Position(3,7)›  PrintD(6,"david plotkin")›  Position(3,9)›  PrintD(6,"ÐÒÅÓÓ óôáòô")›  WHILE Consol<>6 DO›    colpf3=Fate›    Wsync=0›    colpf0=128-vcount+rtclock RSH 2›    colpf1=vcount+rtclock RSH 2›  OD›RETURN››PROC Gr0Init()›;Set up the address of each screen›;line and initialize›CARD xx›  Graphics(0)›  CursIn=1›  Print(" ")›  FOR xx=0 TO 23 DO›    Linept(xx)=Scrn+(40*xx)›  OD›  FOR xx=0 TO 29 DO›    Chopperstatus(xx)=0›    Chopperx(xx)=0›    Choppery(xx)=0›    Misx(xx)=0›    Misy(xx)=0›    MisStatus(xx)=0›    TrStatus(xx)=0›  OD›  FOR xx=0 TO 59 DO›    ExpStatus(xx)=0›  OD›  FOR xx=0 TO 19 DO›    Ll(xx)=0›    Rr(xx)=0›  OD›  Bkgrnd=0›  Update()›RETURN››PROC Plot0(BYTE x,y,ch)›;Plot a char at location x,y›BYTE ARRAY line›  line=Linept(y)›  line(x)=ch›RETURN››BYTE FUNC Locate0(BYTE x,y)›;Returns the value of the char at x,y›BYTE ARRAY line›  line=Linept(y)›RETURN(line(x))››PROC Noise()›;the explosion noises›  IF Loud=0 AND Loud1=0›            AND Freq=169 THEN›    RETURN›  FI›  IF Loud THEn›    Loud==-2›    Sound(0,90,8,Loud)›  FI›  IF Loud1 THEN›    Loud1==-2›    Sound(1,150,8,Loud1)›  FI›  IF Freq<168 THEN›    Freq==+8›    Sound(2,Freq,10,4)›  ELSE›    Freq=169›    Sound(2,0,0,0)›  FI›RETURN››PROC HitChute(BYTE wh)›;see which chute was hit by missile wh›BYTE lp›  FOR lp=0 TO 29 DO›    IF Misx(wh)=Trx(lp) AND›         (Misy(wh)=Try(lp) OR›          Misy(wh)=Try(lp)+1) THEN›      TrStatus(lp)=2›      Plot0(trx(lp),Try(lp),0)›      Plot0(Trx(lp),Try(lp)+1,10)›      Plot0(Trx(lp),Try(lp)+2,0)›      EXIT›    FI›  OD›  IF Try(lp) LSH 3 < Freq THEN›    Freq=Try(lp) LSH 3›  FI›RETURN››PROC HitMan(BYTE wh)›;see which man was hit by missile wh›BYTE lp›  FOR lp=0 TO 29 DO›    IF Misx(wh)=Trx(lp) AND›         (Misy(wh)=Try(lp)+1 OR›          Misy(wh)=Try(lp)+2) THEN›      TrStatus(lp)=3›      Plot0(Trx(lp),Try(lp)+1,6)›      Plot0(Trx(lp),Try(lp),0)›      Plot0(Trx(lp),Try(lp)+2,0)›    FI›  OD›  Loud1=12›RETURN››PROC ExplodeChopper(BYTE lp)›;explosions in place of Chopper lp›BYTE lq›  FOR lq=0 TO 59 STEP 2 DO ;find empty›    IF ExpStatus(lq)=0 THEN›      ExpStatus(lq)=1     ›      ExpStatus(lq+1)=1›      Expx(lq)=Chopperx(lp)›      Expx(lq+1)=Chopperx(lp)+1›      Expy(lq)=Choppery(lp)›      Expy(lq+1)=Choppery(lp)›      Chopperstatus(lp)=0›      Plot0(Expx(lq),Expy(lq),6)›      Plot0(Expx(lq+1),Expy(lq+1),6)›      EXIT›    FI›  OD›RETURN››PROC HitChopper(BYTE wh)›;which chopper was hit by missile wh›BYTE lp›  FOR lp=0 TO 29 DO›    IF Misy(wh)=Choppery(lp) AND›       (Misx(wh)=Chopperx(lp) OR›        Misx(wh)=Chopperx(lp)+1) THEN›      ExplodeChopper(lp)›      EXIT›    FI›  OD›  Loud=12›RETURN››PROC MissileHit(BYTE wh)›;see if missile wh hit anything›BYTE dum›  dum=Locate0(Misx(wh),Misy(wh))›  IF dum=0 THEN›    Plot0(Misx(wh),Misy(wh),84)›    RETURN›  FI›  MisStatus(wh)=0›  IF dum=1 OR dum=2 THEN›    HitChopper(wh)›    Score==+1›  ELSEIF (dum=7 AND Indx<6 OR›          dum=8 AND Indx>3) THEN›    HitChute(wh)›    Score==+2›  ELSEIF (dum=8 AND Indx<4 OR›          dum=9 AND Indx>1) THEN›    HitMan(wh)›    Score==+1›  FI›RETURN››PROC Modify()›;Modify the RAM character set›CARD xx›  FOR xx=0 TO 103 DO›    Charset(xx+8)=ShapeTable(xx)›  OD›RETURN››PROC LaunchTrooper(BYTE wh)›;drop a paratrooper from chopper wh›BYTE lp›  IF Fate>240-(Level LSH 1) THEN›    FOR lp=0 TO 29 DO ;find MT trooper›      IF TrStatus(lp)=0 THEN ;got one›        TrStatus(lp)=1›        Trx(lp)=Chopperx(wh)›        IF Trx(lp)=0 THEN›          Trx(lp)=1›        FI›        Try(lp)=Choppery(wh)+1›        Plot0(Trx(lp),Try(lp),7)›        Plot0(Trx(lp),Try(lp)+1,8)›        Plot0(Trx(lp),Try(lp)+2,9)›        EXIT›      FI›    OD›  FI›RETURN››PROC EraseChopper(BYTE wh)›;erase chopper number wh›  Plot0(Chopperx(wh),Choppery(wh),0)›  Plot0(Chopperx(wh)+1,Choppery(wh),0)›  Chopperstatus(wh)=0›  Chopperx(wh)=0›  Choppery(wh)=0›RETURN››PROC DrawChopper(BYTE wh)›;draw chopper number wh›  Plot0(Chopperx(wh),Choppery(wh),1)›  Plot0(Chopperx(wh)+1,Choppery(wh),2)›RETURN››PROC ClearScreen()›;clear the screen›BYTE lp›  FOR lp=0 TO 29›  DO›    IF Chopperstatus(lp) THEN›      EraseChopper(lp)›    FI›    IF TrStatus(lp) THEN›      TrStatus(lp)=0›      Plot0(Trx(lp),Try(lp),0)›      Plot0(Trx(lp),Try(lp)+1,0)›      Plot0(Trx(lp),Try(lp)+2,0)›    FI›    IF MisStatus(lp)=1 THEN›      MisStatus(lp)=0›      Plot0(Misx(lp),Misy(lp),0)›    FI›  OD›  FOR lp=0 TO 59 STEP 2 DO›    IF ExpStatus(lp)=1 THEN›      ExpStatus(lp)=0›      ExpStatus(lp+1)=0›      Plot0(Expx(lp),Expy(lp),0)›      Plot0(Expx(lp+1),Expy(lp+1),0)›    FI›  OD›RETURN››PROC MoveChopper()›;move the choppers›BYTE lp,ps=[0]›  FOR lp=0 TO 29 DO›    IF Chopperstatus(lp)=1 THEN ;right›      IF Chopperx(lp)=38 THEN›        EraseChopper(lp)›      ELSE›        Plot0(Chopperx(lp),›              Choppery(lp),0)›        Chopperx(lp)==+1›        DrawChopper(lp)›        LaunchTrooper(lp)›      FI›    FI›    IF Chopperstatus(lp)=2 THEN ;left›      IF Chopperx(lp)=0 THEN›        EraseChopper(lp)›      ELSE›        Plot0(Chopperx(lp)+1,›              Choppery(lp),0)›        Chopperx(lp)==-1›        DrawChopper(lp)›        LaunchTrooper(lp)›      FI›    FI›  OD›  IF ps=0 THEN ›    Charset(8)=56›    Charset(16)=28›    ps=1›  ELSE›    ps=0›    Charset(8)=254›    Charset(16)=127›  FI›RETURN››PROC LaunchChopper()›;Decide whether to send off a new›;chopper, which side, how high up›BYTE lp›  IF Fate>230-(Level LSH 1) THEN›    FOR lp=0 TO 29 DO ;find MT chopper›      IF Chopperstatus(lp)=0 THEN›        Choppery(lp)=Rand(Hard)›        IF Fate>128 THEN›          Chopperx(lp)=38 ;right side›          Chopperstatus(lp)=2›        ELSE›          Chopperx(lp)=0 ;left side›          Chopperstatus(lp)=1›        FI›        DrawChopper(lp)›        EXIT›      FI›    OD›  FI›RETURN››PROC DrawBase()›;draw the base›BYTE lp›  FOR lp=19 TO 21 DO›    Plot0(lp,22,128)›  OD›  Plot0(20,21,4)›RETURN››PROC AimGun()›;read the joystick and move the base›  IF Stick=11 THEN›    Ps=3›  ELSEIF Stick=7 THEN›    Ps=5›  ELSE›    Ps=4›  FI›  Plot0(20,21,Ps)›RETURN››PROC Shoot()›;send off a bullet›BYTE trig=644,lp,flg=[0]›  IF trig=1 OR flg=0 THEN›    flg=1›    RETURN›  FI›  FOR lp=0 TO 29 DO ;find empty shot›    IF MisStatus(lp)=0 THEN ;got one›      MisStatus(lp)=1›      Misy(lp)=20›      IF Ps=3 THEN›        Misx(lp)=19›      ELSEIF Ps=5 THEN›        Misx(lp)=21›      ELSE›        MISX(lp)=20›      FI›      MissileHit(lp)›      EXIT›    FI›  OD›  flg=0›RETURN››PROC MoveShots()›;move the fired bullets›BYTE lp›  FOR lp=0 TO 29 DO ;for each shot›    IF MisStatus(lp)=1 THEN›      Plot0(Misx(lp),Misy(lp),0)›      IF Stick=11 THEN›        Misx(lp)==-1›      ELSEIF Stick=7 THEN›        Misx(lp)==+1›      ELSE›        Misy(lp)==-1›      FI›      IF (Misx(lp)<>39 AND›          Misy(lp)<>255 AND›          Misx(lp)<>0) THEN›        MissileHit(lp)›      ELSE›        MisStatus(lp)=0›      FI›    FI›  OD›RETURN››PROC MoveExplosions()›;move the explosions›BYTE lp›  FOR lp=0 TO 59 STEP 2 DO›    IF ExpStatus(lp)=1 THEN›      Plot0(Expx(lp),Expy(lp),0)›      Plot0(Expx(lp+1),Expy(lp+1),0)›      Expy(lp)==+1›      Expy(lp+1)==+1›      Expx(lp)==-1›      Expx(lp+1)==+1›      IF Expy(lp)<>22 AND Expx(lp)<>0›         AND Expx(lp+1)<>39 THEN›        Plot0(Expx(lp),Expy(lp),6)›        Plot0(Expx(lp+1),Expy(lp+1),6)›      ELSE›        ExpStatus(lp)=0›        ExpStatus(lp+1)=0›      FI›    FI›  OD›RETURN››PROC BaseExplode()›;explode the base›BYTE ARRAY endx(0)=[16 24 17 23 20],›           endy(0)=[22 22 19 19 17]›BYTE lp,time=20›  color=38›  FOR lp=0 TO 4 DO›    Plot(20,22)›    DrawTo(endx(lp),endy(lp))›  OD›  FOR lp=0 TO 16 DO›    Sound(0,Fate,8,16-lp)›    Sound(1,Fate,8,16-lp)›    time=0›    DO›      UNTIL time=15›    OD›  OD›  SndRst()›  color=32›  FOR lp=0 TO 4 DO›    Plot(20,22)›    DrawTo(endx(lp),endy(lp))›  OD›RETURN››PROC EndRight()›;move the troopers from the right›;to the base›BYTE lp,lq,nn,time=20›  FOR lp=0 TO 19 DO›    IF Rr(lp)=1 THEN›      lq=21+lp›      WHILE lq>20 DO›        IF nn=12 THEN›          nn=13›        ELSE›          nn=12›        FI›        Plot0(lq,22,nn)›        time=0›        DO›          UNTIL time=10›        OD›        Plot0(lq,22,0)›        lq==-1›      OD›      Plot0(21,22,11)›    FI›  OD›  FOR lp=0 TO 3 DO›    Plot0(21,22-lp,11)›    time=0›    DO›      UNTIL time=10›    OD›  OD›  BaseExplode()›RETURN››PROC EndLeft()›;Move the troopers from the left to›;the base›BYTE lp,lq,lc,nn,time=20›  FOR lp=0 TO 19 DO›    lq=19-lp›    IF Ll(lq)=1 THEN›      FOR lc=lq TO 19 DO›        IF nn=12 THEN›          nn=13›        ELSE›          nn=12›        FI›        Plot0(lc,22,nn)›        time=0›        DO›          UNTIL time=10›        OD›        Plot0(lc,22,0)›      OD›      Plot0(19,22,11)›    FI›  OD›  FOR lp=0 TO 3 DO›    Plot0(19,22-lp,11)›    time=0›    DO›      UNTIL time=10›    OD›  OD›  BaseExplode()›RETURN››PROC EndPrint()›;print the end of game message and›;test for new game›BYTE trig=644,lp›  Position(10,7)›  Print("Game Over...Final Score:")›  Position(15,8)›  PrintC(Score)›  Position(15,9)›  Print("FINAL LEVEL :")›  PrintB(Level)›  Position(10,20)›  Print("Press ÆÉÒÅ to play again")›  DO›    UNTIL trig=0›  OD›  DownL=0›  DownR=0›  Put(125)›  FOR lp=0 TO 19 DO›    Ll(lp)=0›    Rr(lp)=0›  OD›  Score=0›  Level=1›  DrawBase()›  Update()›  Hard=15›RETURN››PROC GameOverTwo()›;game over when four troopers down›BYTE lp›  SndRst()›  ClearScreen()›  Loud=0›  Loud1=0›  Freq=169›  FOR lp=0 TO 19 DO›    IF Ll(lp)=1 THEN›      Plot0(lp,22,11)›    FI›    IF Rr(lp)=1 THEN›      Plot0(lp+21,22,11)›    FI›  OD›  IF DownL=4 THEN›    EndLeft()›  ELSE›    EndRight()›  FI›  EndPrint()›RETURN››PROC GameOverOne()›;game over when trooper lands on base›BYTE lp›  SndRst()›  ClearScreen()›  Loud=0›  Loud1=0›  Freq=169›  FOR lp=0 TO 19 DO›    IF Ll(lp)=1 THEN›      Plot0(lp,22,11)›    FI›    IF Rr(lp)=1 THEN›      Plot0(lp+21,22,11)›    FI›  OD›  BaseExplode()›  EndPrint()›RETURN››PROC TrooperDown(BYTE wh)›;redraw trooper wh at bottom of screen›BYTE cc›  TrStatus(wh)=0›  cc=Trx(wh)›  Plot0(Trx(wh),Try(wh),0) ;erase chute›  Plot0(Trx(wh),Try(wh)+1,11) ;replace›  IF Trx(wh)<20 AND Ll(cc)=0 THEN›    Ll(cc)=1›    DownL==+1›  ELSEIF Trx(wh)>20 AND›         Rr(cc-21)=0 THEN›    Rr(cc-21)=1›    DownR==+1›  ELSEIF Trx(wh)=20 THEN›    GameOverOne()›  FI›  IF DownL=4 OR DownR=4 THEN›    GameOverTwo()›  FI›RETURN››PROC TrooperFall()›;make trooper fall when chute hit›BYTE lp,qq,cc›  FOR lp=0 TO 29 DO›    IF TrStatus(lp)=2 THEN›      Plot0(Trx(lp),Try(lp)+1,0)›      Try(lp)==+1›      If Try(lp)=21 THEN›        cc=Trx(lp)›        IF Trx(lp)<20 AND Ll(cc)=1 THEN›          DownL==-1›          Ll(cc)=0›        ELSEIF Trx(lp)>20 AND›               Rr(cc-21)=1 THEN›          Rr(cc-21)=0›          DownR==-1›        FI›      FI›      IF (Try(lp)<22 AND Trx(lp)<>20)›          OR (Try(lp)<20 AND›          Trx(lp)=20) THEN›        Plot0(Trx(lp),Try(lp)+1,10)›      ELSE›        TrStatus(lp)=0›      FI›    FI›  OD›RETURN››PROC MoveTroopers()›;move paratroopers down screen›BYTE lp,qq›BYTE ARRAY Trooper(0)=›     [60 126 255 255 195  66  36  24›      60  36  24 255  60  24  36 102›       0   0   0   0   0   0   0   0]›  FOR lp=0 TO Indx DO›    Charset(56+lp)=0›  OD›  MoveBlock(Charset+56+Indx+1,›            Trooper,16)›  Indx==+1›  IF Indx<8 THEN›    RETURN›  FI›  Indx=0›  FOR lp=0 TO 29 DO›    IF TrStatus(lp)=1 THEN›      Plot0(Trx(lp),Try(lp),0)›      Try(lp)==+1›      IF Try(lp)=21 THEN›        TrooperDown(lp)›      FI›    FI›    IF TrStatus(lp)=3 THEN›      TrStatus(lp)=0›      Plot0(Trx(lp),Try(lp)+1,0)›    FI›  OD›  MoveBlock(Charset+56,Trooper,24)›  FOR lp=0 TO 29 DO›    IF TrStatus(lp)=1 THEN›      Plot0(Trx(lp),Try(lp),7)›      Plot0(Trx(lp),Try(lp)+1,8)›      Plot0(Trx(lp),Try(lp)+2,9)›    FI›  OD›RETURN››PROC NewLevel()›;go to higher level›BYTE lp,time=20›  Level==+1›  IF Level>100 THEN›    Level=100›  FI›  SndRst()›  Loud=0›  Loud1=0›  Freq=169›  Comp==+300›  FOR lp=10 TO 150 STEP 10 DO›    Sound(0,lp,10,4)›    Sound(1,lp+10,10,4)›    time=0›    DO›      UNTIL time=2›    OD›  OD›  Position(25,23)›  PrintB(Level)›  IF Level>8 THEN›    Hard=19›  FI›  SndRst()›RETURN››PROC Main()›BYTE time=20,lp,ch=764›  Title()›  Gr0Init()›  Snd1=0›  Snd2=3›  Download()›  Modify()›  DrawBase()›  ScoreLine()›  DO›    LaunchChopper()›    MoveChopper()›    MoveExplosions()›    Noise()›    TrooperFall()›    MoveTroopers()›    Position(8,23)›    PrintC(Score)›    IF Score>Comp THEN›      NewLevel()›    FI›    time=0›    FOR lp=2 TO 6 STEP 2 DO›      AimGun()›      Shoot()›      MoveShots()›      DO›        UNTIL time=lp›      OD›    OD›  OD›RETURN› ›