10 ' AMAZIN -- DRAW A MAZE UP TO 14 BY 21
  20 ' EDUSYSTEM 50 REFACTORING BY RENAUD FIVET
  90 DEF FNR(R)=INT(RND(1)*R+1)
 100 RANDOMIZE
 110 DIM V(13,20)
 120 PRINT "WHAT ARE YOUR WIDTH AND LENGTH";\ INPUT H,V
 122 PRINT
 130 IF H<2 THEN 132\ IF H>14 THEN 132
 131 IF V<2 THEN 132\ IF V<=21 THEN 150
 132 PRINT "MEANINGLESS DIMENSIONS, TRY AGAIN"
 140 PRINT
 141 GOTO 120
 150 PRINT
 151 PRINT
 160 ' PICK ENTRY CELL ON TOP ROW AND DRAW UPPER WALL
 161 C=H*V        ' COUNT OF CELLS LEFT TO FILL
 162 R=FNR(H)-1   ' R,0 TOP ENTRY CELL COORD
 163 H=H-1\ V=V-1 ' COORD IN 0..H,0..V
 170 FOR I=0 TO H
 171  IF I=R THEN 174
 172   PRINT ":--";
 173   GOTO 175
 174  PRINT ":  ";
 175 NEXT I
 185 PRINT ":"
 187 ' PICK EXIT CELL ON BOTTOM ROW AS CURRENT
 190 R=FNR(H+1)-1\ S=V ' R,S CURRENT CELL COORD
 192 V(R,S)=2
 193 GOTO 999
 209 ' SCAN FOR NEXT POSITION TO CHECK
 210 R=R+1
 215 IF R<=H THEN 250
 220  R=0\ S=S+1
 225  IF S<=V THEN 250
 230   S=0
 250 IF V(R,S)=0 THEN 210
 255 ' CHECK FOR ADJACENT UNMARKED CELLS AND PICK ONE AT RANDOM
 260 T=1
 261 IF R=0 THEN 262\ IF V(R-1,S)<>0 THEN 262\ T=T+1 ' L
 262 IF S=0 THEN 263\ IF V(R,S-1)<>0 THEN 263\ T=T+2 ' U
 263 IF R=H THEN 264\ IF V(R+1,S)<>0 THEN 264\ T=T+4 ' R
 264 IF S=V THEN 265\ IF V(R,S+1)<>0 THEN 265\ T=T+8 ' D
 265 '           0,  L,  U, LU,  R, LR, UR,LUR,  D, LD, UD,LUD, RD,LRD,URD,LURD
 300 ON T GOTO 210,790,820,370,860,450,590,310,910,500,640,350,710,430,570
 310 ON FNR(3) GOTO 790,820,860 ' LUR
 350 ON FNR(3) GOTO 790,820,910 ' LUD
 370 ON FNR(2) GOTO 790,820     ' LU
 430 ON FNR(3) GOTO 790,860,910 ' LRD
 450 ON FNR(2) GOTO 790,860     ' LR
 500 ON FNR(2) GOTO 790,910     ' LD
 570 ON FNR(3) GOTO 820,860,910 ' URD
 590 ON FNR(2) GOTO 820,860     ' UR
 640 ON FNR(2) GOTO 820,910     ' UD
 710 ON FNR(2) GOTO 860,910     ' RD
 720 '
 790 ' REMOVE LEFT WALL
 800 R=R-1\ V(R,S)=3\ GOTO 999
 820 ' REMOVE UP WALL
 830 S=S-1\ V(R,S)=2\ GOTO 999
 860 ' REMOVE RIGHT WALL
 870 V(R,S)=V(R,S)+2\ R=R+1\ GOTO 998
 910 ' REMOVE DOWN WALL
 922 V(R,S)=V(R,S)+1\ S=S+1
 998 V(R,S)=1
 999 C=C-1\ IF C>0 THEN 260 ' LOOP WHILE C
1000 ' DRAW MAZE
1010 FOR J=0 TO V
1011  PRINT "I";
1012  FOR I=0 TO H
1013   IF V(I,J)<3 THEN 1030
1020    PRINT "   ";
1021    GOTO 1040
1030    PRINT "  I";
1040  NEXT I
1041  PRINT
1043  FOR I=0 TO H
1045  IF V(I,J)<=1 THEN 1060
1050   IF V(I,J)=3 THEN 1060
1051    PRINT ":  ";
1052    GOTO 1070
1060    PRINT ":--";
1070  NEXT I
1071  PRINT ":"
1072 NEXT J
1073 END