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Run Magazine ReRun 1986 September & October
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rerun-1986-09-10.d64
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turtle tutor
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.txt
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Commodore BASIC
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2022-09-20
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6KB
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273 lines
10 rem arrays
12 dim b(12),a$(36),b$(36),c$(12)
14 :
16 rem title
18 poke 53280,7:poke 53281,7
20 a$="*":tl=40:print "[147] ";a$;:for f=1 to 3
22 for a=1 to 6:gosub 2750:print "[157] [157]";a$;:next a
24 for a=1 to 5:gosub 2750:print "[157] [157][157]";a$;:next a
26 gosub 2750:print "[157] [157]";a$;:read b$:gosub 2950
28 for a=1 to 5:print "[157] ";:gosub 2750:print "[157]";a$;:gosub 2750:next a
29 next f:gosub 2550:d=0
30 :
32 rem instructions
34 b$="[147][144] elmer's instructions for you:"
36 tl=1:gosub 2950:print "[157] [157]";a$;
38 for a=1 to len(b$)-3:print "[157] [157][157]*";:gosub 2750:next a
40 read b$:if b$="end" then 60
42 print "[157] [157]";a$;:gosub 2950
44 read b$:if b$="end" then 60
46 print "[157] [157]";a$;:a=len(b$):for c=1 to a
48 print "[157]";mid$(b$,a-c+1,1)"[157][157]";a$;
50 gosub 2750:next c:goto 40
60 tl=40
62 get b$:if b$<>"" then 100
64 print "[157] ";:gosub 2750
66 print "[157]";a$;:gosub 2750:goto 62
100 :
140 rem variables
170 read b$:if b$="end"thenbl=b:goto200
180 b=b+1:b$(b)=b$:b(b)=len(b$)
190 read c(b):goto 170
200 s$=" "
210 er$="[145]"+s$+s$+s$+"[145]"
220 tl=50:al=36:d=54272:u=10
699 :
700 rem ....restart address
710 :
730 rem statement list display
735 poke 53280,3:poke 53281,3:poke 646,6
740 print "[147]";:n=18:for o=1 to 18
750 print "";right$(str$(o),2);". ";
760 print "";a$(o);tab(20);
770 print "";right$(str$(o+n),2);". ";
780 print "";a$(o+n):next o:print
790 if q=1 then 980
800 :
810 rem line # input
830 input "line #, 'e' or 'new'";i$
840 print er$:if i$="e" then 1610
850 if i$<>"new" then 870
860 for a=1 to 36:a$(a)="":next:goto710
870 i=len(i$):if i<1 or i>3 then 940
880 if i$="0" then 940
890 n=asc(i$):if n<49 or n>57 then 940
900 n=asc(right$(i$,1))
910 if n<49 and n>57 then 940
920 a=val(i$)
930 if a>0 and a=<al then 980
940 gosub 2500:if u=0 then 810
950 print "[147]"
960 goto 710
970 :
980 rem statement display
1000 q=1:print "[145]";
1010 for m=1 to 3:for n=0 to 3
1020 b=m+n*3:if b>bl then 1040
1030 print tab(n*10);b$(b);
1040 next n:print:next m
1050 print "i[158]nsert d[158]elete ";
1060 print "b[158]ack to line #"
1070 :
1080 rem statement input
1100 print "line";a;:i$="":input i$
1110 print er$:if i$="" then gosub 2500:goto 1070
1120 if i$="i" then 1540
1130 if i$="d" then 1580
1140 if i$="b" then q=0:goto 710
1150 :
1160 rem is 'i$' valid?
1180 b=0:i=len(i$)
1190 b=b+1:if b>bl then gosub 2500:goto 1070
1200 if left$(i$,b(b))<>b$(b) then 1190
1210 rem ....stmt #c
1220 c=c(b):if c>0 then 1260
1230 rem ....stmt type 0
1240 if i$=b$(b) then a$(a)=i$:q=0:goto 710
1250 goto 1370
1260 m$=right$(i$,i-b(b))
1270 gosub 2590
1280 j$=m$:j=len(j$):if c>1 then 1420
1290 rem ....stmt type 1
1300 if j=0 or j>2 then 1370
1310 n=asc(left$(j$,1))
1320 if n<48 or n>57 then 1370
1330 n=asc(right$(j$,1))
1340 if n<48 or n>57 then 1370
1350 n=val(j$):if b=8 and n<16 then 1460
1360 if b<>8 and n>0 then 1460
1370 gosub 2500:goto 1070
1420 if c>2 then 1480
1430 rem ....stmt type 2
1440 if j<>1 then 1370
1450 n=asc(j$):if n<33 or n>95 then 1370
1460 rem ....i$ is valid statement
1470 a$(a)=b$(b)+" "+j$:q=0:goto 710
1480 if c>3 then 1370
1490 rem ....stmt type 3
1500 if mid$(i$,5,1)=" " then 1520
1510 i$=left$(i$,4)+" "+mid$(i$,5)
1520 n=len(i$):if n<6 or n>15 then 1370
1530 a$(a)=i$:q=0:goto 710
1540 rem ....insert blank line
1550 for m=35 to a step -1
1560 a$(m+1)=a$(m):next m
1570 a$(a)="":q=0:goto 710
1580 rem ....delete line
1590 if a=36 then 1600
1595 for m=a to 35:a$(m)=a$(m+1):next
1600 a$(36)="":q=0:goto 710
1610 :
1620 rem begin execution
1640 x=1:y=1:rem initial position
1650 e=2:rem initial pen position
1660 h$="*":rem initial character
1670 l=6:rem initial color #
1680 poke 53280,5:rem border color
1690 print "[147]":gosub 2770:gosub 2710
1700 rem ....statement list
1710 for a=1 to al:a$=a$(a)
1720 if a$="" then 2330
1730 b=0
1740 b=b+1
1750 if left$(a$,b(b))<>b$(b) then 1740
1760 on b goto 1780,1850,1920,1990,2060,2100,2130,2170,2210,2290
1770 :
1780 rem ....right
1790 m$=right$(a$,len(a$)-b(b))
1800 gosub 2590:m=val(m$)
1810 for n=1 to m:gosub 2370
1820 x=x+1:if x=41 then x=1
1830 gosub 2710:next n:goto 2330
1840 :
1850 rem ....up
1860 m$=right$(a$,len(a$)-b(b))
1870 gosub 2590:m=val(m$)
1880 for n=1 to m:gosub 2370
1890 y=y-1:if y=0 then y=25
1900 gosub 2710:next n:goto 2330
1910 :
1920 rem ....down
1930 m$=right$(a$,len(a$)-b(b))
1940 gosub 2590:m=val(m$)
1950 for n=1 to m:gosub 2370
1960 y=y+1:if y=26 then y=1
1970 gosub 2710:next n:goto 2330
1980 :
1990 rem ....left
2000 m$=right$(a$,len(a$)-b(b))
2010 gosub 2590:m=val(m$)
2020 for n=1 to m:gosub 2370
2030 x=x-1:if x=0 then x=40
2040 gosub 2710:next n:goto 2330
2050 :
2060 rem ....pen up
2070 if e=0 then e=1
2080 goto 2330
2090 :
2100 rem ....pen down
2110 e=0:goto 2330
2120 :
2130 rem ....char
2140 h$=right$(a$,1):gosub 2770
2150 p=983+x+y*40:poke p,k
2152 gosub 2750:goto 2330
2160 :
2170 rem ....color
2180 l=val(mid$(a$,6)):p=983+x+y*40
2190 poke p+d,l:gosub 2750:goto 2330
2200 :
2210 rem ....text
2220 a$=mid$(a$,6):m=len(a$)
2225 x=x-1:if x=0 then x=40
2230 gosub 2370:j=k:for n=1 to m
2240 h$=mid$(a$,n,1):gosub 2770
2250 x=x+1:if x=41 then x=1
2260 gosub 2710:next n
2270 k=j:f=1:m=1:goto 1810
2280 :
2290 rem ....stop
2300 a$=""
2310 get a$:if a$="" then 2310
2320 goto 2330
2330 next a:q=0:goto 710
2340 :
2350 rem subroutines
2360 :
2370 rem ....erase previous point?
2380 if f=1 then f=0:return
2390 if e=1 then e=2:return
2400 if e=2 then poke p+d,v:poke p,w
2410 return
2420 :
2430 rem ....instruction input
2440 print ""
2450 print " press any key to ";
2460 print "continue":a$=""
2470 get a$:if a$="" then 2470
2480 print "[147]":return
2490 :
2500 rem ....error message
2510 print ,"[144]i don't understand that"
2520 gosub 2560:print er$
2530 print ,"please try again"
2540 gosub 2560:print er$:return
2550 :
2560 rem ....screen message delay
2570 for t=1 to 500:next t:return
2580 :
2590 rem ....truncate m$
2600 if m$="" then return
2610 m=asc(left$(m$,1))
2620 if m=32 then 2640
2630 if m<>160 then 2650
2640 m$=right$(m$,len(m$)-1):goto 2610
2650 if m$="" then return
2660 m=asc(right$(m$,1))
2670 if m=32 then 2690
2680 if m<>160 then return
2690 m$=left$(m$,len(m$)-1):goto 2650
2700 :
2710 rem ....poke screen character
2720 p=983+x+y*40
2730 v=peek(p+d):wl=w:w=peek(p)
2740 poke p+d,l:poke p,k
2750 for t=1 to tl:next t:return
2760 :
2770 rem ....calc screen display value
2780 h=asc(h$):if h<64 then k=h:return
2790 k=h-64:return
2800 :
2950 for c=1 to len(b$)
2960 print "[157]";mid$(b$,c,1);a$;
2970 gosub 2750:next c:return
3000 :
3002 rem fixed data
3004 :
3006 rem ....player instructions
3008 data "[144]hi, i'm elmer.","i'm a turtle.","let's play a game....."
3010 data "elmer is a tiny turtle who can draw and"
3012 data " write all over the screen if you give"
3014 data " him a list of simple instructions. "
3016 data " "
3018 data "first, enter either a line number on "
3020 data " the list, or 'new' to erase the whole"
3022 data " list, or 'e' to watch elmer follow "
3024 data " your instructions. "
3026 data " "
3028 data "if you entered a list line number, you "
3030 data " can then enter one of the instruc- "
3032 data " tions shown below the list. "
3033 data " "
3034 data "you can also delete or insert lines. "
3036 data " "
3037 data " "
3038 data " press any key to start playing...."
3040 data end
3110 :
3120 rem ....elmer instructions
3130 data right,1,up,1,down,1,left,1
3140 data pen up,0,pen down,0,char,2
3150 data color,1,text,3,stop,0
3160 data end