REM Advent of Code 2022: Day 6, part 1 and 2
REM Written in Applesoft BASIC

 5  HOME 
 10 A = 1000
 20 R = 0
 50  PRINT  CHR$ (4),"OPEN INPUT"
 60  PRINT  CHR$ (4),"READ INPUT"
 70  ONERR  GOTO 900
 100  PRINT "INITIALIZING COMMUNICATION SYSTEM";
 105 A = 350
 110  FOR I = 0 TO 6
 120  GOSUB 1000
 130  PRINT ".";
 140  NEXT I
 150  PRINT 
 200  PRINT "OPENING SIGNAL DATASTREAM";
 210  FOR I = 0 TO 6
 220  GOSUB 1000
 230  PRINT ".";
 240  NEXT I
 250  PRINT 
 260  PRINT 
 300  PRINT "SCANNING FOR START-OF-PACKET MARKER:"
 310  HTAB 1
 320  VTAB 8
 330  PRINT "||||";
 340  HTAB 1
 350  VTAB 10
 360  PRINT "||||";
 400  HTAB 1
 410  VTAB 9
 420  PRINT S$;
 430  IF  LEN (S$) >  = 4 GOTO 500
 440  GET C$
 450 S$ = C$ + S$
 455  IF  LEN (S$) > 40 THEN S$ =  MID$ (S$,1,40)
 460 A = 80
 470  GOSUB 1000
 475 R = R + 1
 480  GOTO 400
 500  HTAB 1
 510  VTAB 7
 530  IF  MID$ (S$,1,1) =  MID$ (S$,2,1) THEN  PRINT "/\  ";: GOTO 600
 540  IF  MID$ (S$,1,1) =  MID$ (S$,3,1) THEN  PRINT "/-\ ";: GOTO 600
 550  IF  MID$ (S$,1,1) =  MID$ (S$,4,1) THEN  PRINT "/--\";: GOTO 600
 560  IF  MID$ (S$,2,1) =  MID$ (S$,3,1) THEN  PRINT " /\ ";: GOTO 600
 570  IF  MID$ (S$,2,1) =  MID$ (S$,4,1) THEN  PRINT " /-\";: GOTO 600
 580  IF  MID$ (S$,3,1) =  MID$ (S$,4,1) THEN  PRINT "  /\";: GOTO 600
 590  PRINT "    ";
 595  GOTO 700
 600  GOTO 440
 620  VTAB 14
 700  HTAB 1
 710  VTAB 13
 715 A = 1300
 720  PRINT "MARKER FOUND AT INDEX ";R;"."
 725  GOSUB 1000
 730  PRINT 
 740  PRINT "ENGAGING FULL-SPEED SEARCH FOR START-OF-MESSAGE MARKER:"
 750  GOSUB 1000
 760  GOTO 2000
 900  PRINT  CHR$ (4),"CLOSE"
 910  END 
 1000  FOR Z = 0 TO A: NEXT Z
 1010  RETURN 
 2000  HTAB 1
 2010  VTAB 19
 2020  PRINT "||||||||||||||";
 2030  HTAB 1
 2040  VTAB 21
 2050  PRINT "||||||||||||||";
 2060  PRINT  CHR$ (4),"CLOSE"
 2070  PRINT  CHR$ (4),"OPEN INPUT"
 2080  PRINT  CHR$ (4),"READ INPUT"
 2090 S$ = "":R = 0
 2095 M = 0
 2100  HTAB 1
 2110  VTAB 20
 2120  PRINT S$;
 2130  GET C$
 2140 S$ = C$ + S$
 2145 R = R + 1
 2150  IF  LEN (S$) < 14 GOTO 2100
 2160  IF  LEN (S$) > 40 THEN S$ =  MID$ (S$,1,40)
 2170  IF M > 0 THEN M = M - 1: GOTO 2100
 2190 I = 1
 2200 M = 0
 2210  FOR J = I + 1 TO 14
 2220  IF  MID$ (S$,I,1) =  MID$ (S$,J,1) THEN M = J:J = 14
 2230  NEXT J
 2240  IF M <  > 0 GOTO 2300
 2250 I = I + 1
 2260  IF I < 14 GOTO 2200
 2270  GOTO 2400
 2300  HTAB I
 2310  VTAB 18
 2314  PRINT "              ";
 2318  HTAB I
 2320  FOR J = I TO M
 2330  PRINT "-";
 2340  NEXT J
 2345 M = 14 - M
 2350  GOTO 2100
 2400  HTAB 1
 2410  VTAB 23
 2420  PRINT "MESSAGE FOUND AT INDEX ";R"."
 2425  GOSUB 1000
 2430  GOTO 900