100 REM Basic Month 4 : Lunar Corps Atari 1.0
110 REM original AppleII by FozzTexx
120 REM Atari Turbo Basic XL 1.5 version by papa_robot
135 DIM C1$(1),C2$(1),C3$(1),C4$(1),C5$(1),C6$(1),P$(1),T$(2)
136 DIM S$(5)
200 REM Clear Screen and setup
210 GRAPHICS 0:POKE 82,0:POSITION 0,23:POKE 752,1
215 SETCOLOR 2,0,0:SETCOLOR 1,1,14
220 DIM PEAK$(4):PEAK$=" /\_"
230 COLS=39:ROWS=23:SIZ=COLS+4
232 REM All strings have to be DIMmmed before used
235 DIM L1$(SIZ),L2$(SIZ),BL$(SIZ),SP$(SIZ),SE$(10),LM$(10),ML$(10),LE$(10)
300 EXEC DRAWSF
310 YS=SQR(2)*SQR(ROWS-TL+ZL)-1
320 XE=INT((ZE-ZS)/2)+ZS
330 XV=XE/YS:YV=0
340 X=1:Y=1
400 EXEC SPRITES:LM$=SP$
410 EXEC SPRITES:ML$=SP$:LE$=SE$
420 FOR I=1 TO YS
430   SP$=LE$:EXEC DRAW
440   YV=YV+1
450   X=X+XV:Y=Y+YV
460   SP$=LM$:IF I>=YS-2 THEN SP$=ML$
470   EXEC DRAW
480   FOR J=1 TO 400:NEXT J
490 NEXT I
500 SP$=LE$:EXEC DRAW
510 X=(ZE-ZS)/2+ZS-1:Y=ROWS-TL+ZL-1
520 SP$=LM$:EXEC DRAW
530 SP$="The Eagle has landed":X=(COLS-LEN(SP$))/2:Y=ROWS/2:EXEC DRAW
590 SP$="09-JUL-2019":X=(COLS-LEN(SP$))/2:Y=2:EXEC DRAW
600 SP$="/u/papa_robot":X=(COLS-LEN(SP$))/2:Y=3:EXEC DRAW
605 SP$="Press Start to exit":X=(COLS-LEN(SP$))/2:Y=4:EXEC DRAW
610 REM pause until user press START
890 IF PEEK($D01F)<>6 THEN GOTO 890
900 GRAPHICS 0
999 END
1499 REM Draw sprite in SP$ at X,Y
1500 PROC DRAW
1510   IF Y<1 OR Y>ROWS OR X<1 OR X>COLS THEN ENDPROC
1520 REM Set the left margin to the X position
1530 POSITION 0,1:PRINT :POSITION X,Y:POKE 82,X-1:PRINT :PRINT SP$;
1540 POKE 82,0
1550 ENDPROC
2000 REM Load a sprite from DATA into SP$
2010 PROC SPRITES
2012   REM
2015   SP$="":SE$="":SR=0:SC=0
2020   READ T$,S$:IF LEN(SP$)>0 THEN SP$(LEN(SP$)+1)=CHR$(155)
2030   SP$(LEN(SP$)+1)=S$:SR=SR+1:IF LEN(S$)>SC THEN SC=LEN(S$)
2040   BL$="":FOR I=1 TO LEN(S$):BL$(LEN(BL$)+1)=" ":NEXT I
2050   IF LEN(SE$)>0 THEN SE$(LEN(SE$)+1)=CHR$(155)
2060   SE$(LEN(SE$)+1)=BL$
2070   IF T$<>"SE" THEN GOTO 2020
2080 ENDPROC
2500 REM Draw lunar surface
2501 PROC DRAWSF
2510   DIDUP=0:L1$="":FOR I=1 TO COLS+4:L1$(LEN(L1$)+1)=" ":NEXT I
2520   ZS=0:ZE=0:TL=0
2530   L2$="  ":UP=DIDUP:IF NOT UP AND L1$(3,3)<>" " THEN UP=1
2540   IF NOT DIDUP AND UP THEN DIDUP=UP
2550   Z1=0:Z2=0
2560   FOR I=3 TO COLS+2:PRINT ".";CHR$(30);
2562     REM CHR8 left Arrow
2565     REM MID$ in AppleBasic mid to inexistent index returns empty, in Atari fails as out of bounds, add a space
2567     IF LEN(L1$)<I+2 THEN L1$(I+2,I+2)=" "
2570     C1$=L2$(I-2,I-2):C2$=L2$(I-1,I-1)
2580     C3$=L1$(I-1,I-1):C4$=L1$(I,I)
2590     C5$=L1$(I+1,I+1):C6$=L1$(I+2,I+2)
2600     IF PEAK=0 AND L1$(I-1,I+2)="    " THEN PEAK=INT(RND*3):PEAK=PEAK+(PEAK=2):PEAK=PEAK*INT(RND*2)
2610     IF C2$="/" AND C4$=" " THEN PEAK=2
2620     IF (C1$="_" OR C1$="\") AND C2$=" " THEN PEAK=0
2630     IF C4$<>" " THEN PEAK=0
2640     IF (C3$="\" OR C3$="_") AND C4$=" " THEN PEAK=2
2650     IF C2$="_" AND C6$="/" THEN PEAK=3
2660     IF (C2$="\" OR C2$=" " OR C2$="_") AND C4$=" " AND (C5$="_" OR C5$="/") THEN PEAK=1
2670     IF C2$="\" AND C6$<>" " THEN PEAK=3
2680     IF (C5$="/" OR C5$="_") THEN PEAK=1
2690     IF C4$<>" " THEN PEAK=0
2700     IF UP AND PEAK<>2 THEN PEAK=0
2710     IF PEAK=1 THEN UP=1
2720     IF PEAK=2 THEN UP=0
2730     P$=PEAK$(PEAK+1,PEAK+1):PRINT P$;:L2$(LEN(L2$)+1)=P$
2740     IF PEAK=3 AND NOT Z1 THEN Z1=I
2750     IF PEAK<>3 AND C2$="_" THEN Z2=I
2760     IF Z1 AND Z2 THEN Z3=Z1:Z4=Z2:Z1=0:Z2=0:IF Z4-Z3>=3 AND Z3>ZS THEN ZS=Z3:ZE=Z4:ZL=TL
2770     IF PEAK<>3 OR (C1$="_" AND C2$="_") THEN PEAK=0
2780   NEXT I
2790   L1$=L2$
2800   C2=0
2810   FOR I=3 TO COLS+2
2820     IF L1$(I,I)=" " THEN C2=C2+1
2830   NEXT I
2840   TL=TL+1
2850   IF C2<COLS THEN PRINT :GOTO 2530
2860   ZS=ZS-3:ZE=ZE-3
2861 ENDPROC
9000 DATA SP,(I)
9010 DATA SE,/T\
9020 DATA SP,(I)
9030 DATA SP,/T\
9040 DATA SE, V