10 CLS
20 PRINT "COORDINATE PLOT" 
30 PRINT 
40 DIM X(100),Y(100) 
50 PRINT "X-AXIS: LEFT ENDPOINT, RIGHT ENDPOINT, INCREMENT"; 
60 INPUT A1, A2, A3 
70 PRINT "Y-AXIS: LOWER ENDPOINT, UPPER ENDPOINT, INCREMENT"; 
80 INPUT B1,B2,B3
90 B2=(B2-B1)/B3
100 IF B2<=60 THEN 130  
110 PRINT "Y-RANGE TOO LARGE" 
120 GOTO 70   
130 PRINT "NUMBER OF POINTS TO BE PLOTTED"; 
140 INPUT N 
150 IF N=0 THEN 1080 
160 IF N<=99 THEN 190  
170 PRINT "TOO MANY POINTS" 
180 GOTO 130  
190 FOR I=1 TO N 
200 IF I>1 THEN 230  
210 PRINT "COORDINATES OF POINT ";I; 
220 GOTO 240  
230 PRINT "               POINT ";I; 
240 INPUT X(I), Y(I) 
250 X(I)=INT((X(I)-A1)/A3+.5)
260 Y(I)=INT((Y(I)-B1)/B3+.5)
270 NEXT I 
280 Y(N+1)=INT(B2+.5)+1
290 X(N+1)=INT((A2-A1)/A3+.5)+1
300 PRINT 
310 PRINT "INTERSECTION OF AXES AT (";A1;",";B1;")"
320 PRINT 
330 FOR J=1 TO N 
340 FOR I=1 TO N-J 
350 A=X(I)
360 B=Y(I)
370 C=X(I+1) 
380 D=Y(I+1) 
390 IF A<C THEN 440  
400 X(I)=C
410 Y(I)=D 
420 X(I+1)=A 
430 Y(I+1)=B  
440 NEXT I 
450 NEXT J 
460 T=1 
470 FOR P=0 TO N-1 
480 IF X(P+1)>=0 THEN 500  
490 NEXT P 
500 FOR I=0 TO INT((A2-A1)/A3+.5) 
510 T=T+P 
520 P=0 
530 IF T>N THEN 550  
540 IF X(T)=I THEN 600  
550 IF I=0 THEN 580  
560 PRINT "*"; 
570 GOTO 1050 
580 S=N+1 
590 GOTO 930  
600 FOR L=T TO N 
610 IF X(L)>X(T) THEN 630
620 P=P+1
630 NEXT L 
640 IF P=1 THEN 740  
650 FOR J=1 TO P 
660 FOR L=1 TO P-J 
670 D=Y(T+L-1)
680 B=Y(T+L) 
690 IF D<=B THEN 720  
700 Y(T+L-1)=B 
710 Y(T+L)=D 
720 NEXT L 
730 NEXT J 
740 FOR L=0 TO P-1 
750 Z=Y(T+L) 
760 IF Z>=0 THEN 780  
770 NEXT L 
780 IF I=0 THEN 920  
790 IF Z=0 THEN 810  
800 PRINT "*"; 
810 IF L=P-1 THEN 880  
820 FOR J=L TO P-1 
830 IF Z>B2 THEN 1050 
840 IF Y(T+J)=Z THEN 870  
850 PRINT TAB(1+Z);"+";
860 Z=Y(T+J) 
870 NEXT J 
880 IF Z<0 THEN 1050 
890 IF Z>B2 THEN 1050 
900 PRINT TAB(1+Z);"+"; 
910 GOTO 1050 
920 S=T+L
930 FOR J=0 TO B2 
940 IF Y(S)<>J THEN 1020 
950 PRINT "+"; 
960 FOR K=S TO T+P-1 
970 IF Y(K)=Y(S) THEN 1000 
980 S=K 
990 GOTO 1030 
1000 NEXT K
1010 GOTO 1030 
1020 PRINT "*"; 
1030 NEXT J 
1040 PRINT "Y"; 
1050 PRINT 
1060 NEXT I 
1070 PRINT "X" 
1080 END