The Front-End (Part 2)

C
C       MAZE -  USES A VT100 TO WANDER AROUND.
C               THE VT100 MUST HAVE ADVANCED VIDEO OPTION.
C               ANSI VT100 ESCAPE SEQUENCES ARE USED.
C
C       WRITTEN BY DON MCLEAN
C       OF THE MACNEAL-SCHWENDLER CORP.
C
C       THE PURPOSE OF THIS PROGRAM WAS TO
C               1. LEARN SOMETHING ABOUT THE VT100 GRAPHICS.
C               2. KEEP MY KIDS BUSY ON WEEKENDS. WHILE I TRIED
C                  TO GET SOMETHING ELSE DONE.
C
C       USE OF THIS PROGRAM FOR ANY PURPOSE OTHER THAN FUN
C       IS PROHIBITED.
C
        IMPLICIT INTEGER*4 (A-Z)
C
C       MAZE DIMENSIONS
C       HMAX AND WMAX SHOULD NOT BE LARGER THAN 22 AND 80 RESP.
C
        PARAMETER HMAX=22, WMAX=80, DMAX=4
C
        DIMENSION SLEEP(2)
C
C       DIMENSION IS HMAX*WMAX*DMAX
        INTEGER*2  EXIT(HMAX*WMAX*DMAX), MAT(HMAX*WMAX*DMAX)
        INTEGER*2  LCOUNT(DMAX)
C
        BYTE CLEAR(2)
C
        CHARACTER*200 INPUT
C
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
C
C       CLEAR IS A VT100 RESET
C
        DATA CLEAR / 27, 'c' /
C
C       START - SEE IF AN OLD GAME IS TO BE USED.
C
        WRITE(6,10)
   10   FORMAT(' WELCOME TO MAZE')
C
   20   WRITE(6,30)
   30   FORMAT(' ARE YOU GOING TO PLAY A SAVED GAME? ',$)
        READ(5,40) NC,INPUT
   40   FORMAT(Q,A)
        IF(INDEX(INPUT(1:NC),'Y').NE.0) GO TO 120
        SAVE = 0
C
C       INPUT DIMENSION OF MAZE
C
   50   WRITE(6,60) HMAX
   60   FORMAT(' PLEASE INPUT HEIGHT OF MAZE - DEFAULT = ',I2,' ',$)
        READ(5,40) NC,INPUT
        READ(INPUT,70,ERR=50) HEIGHT
   70   FORMAT(BNI2)
        IF(HEIGHT.EQ.0) HEIGHT=HMAX
        IF(HEIGHT.LT.2) HEIGHT=2
        IF(HEIGHT.GT.HMAX) HEIGHT=HMAX
   80   WRITE(6,90) WMAX
   90   FORMAT(' PLEASE INPUT WIDTH  OF MAZE - DEFAULT = ',I2,' ',$)
        READ(5,40) NC,INPUT
        READ(INPUT,70,ERR=80) WIDTH
        IF(WIDTH.EQ.0) WIDTH = WMAX
        IF(WIDTH.LT.2) WIDTH=2
        IF(WIDTH.GT.WMAX) WIDTH=WMAX
  100   WRITE(6,110)
  110   FORMAT(' PLEASE INPUT DEPTH  OF MAZE - DEFAULT =  1 ',$)
        READ(5,40) NC,INPUT
        READ(INPUT,70,ERR=100) DEPTH
        IF(DEPTH.LE.0) DEPTH = 1
        IF(DEPTH.GT.DMAX) DEPTH = DMAX
        NTERMS = HEIGHT * WIDTH * DEPTH
C
C       GENERATE MAZE
C
        CALL MAZGEN(EXIT,LCOUNT,HEIGHT,WIDTH,DEPTH)
        GO TO 180
C
C       READ IN OLD MAZE
C
  120   WRITE(6,130)
  130   FORMAT(' INPUT SAVED FILE NAME ',$)
        READ(5,40) NC,INPUT
        OPEN(UNIT=7,NAME=INPUT(1:NC),STATUS='OLD',ERR=140,
        1 FORM='UNFORMATTED',READONLY)
        GO TO 160
C
  140   WRITE(6,150)
  150   FORMAT(' SAVE FILE NOT FOUND')
        GO TO 20
  160   READ(UNIT=7) HEIGHT,WIDTH,DEPTH,STARTH,STARTW,STARTD,
        1 ENDH,ENDW,ENDD
        NTERMS = HEIGHT * WIDTH * DEPTH
        READ(UNIT=7) (EXIT(I),I=1,NTERMS)
        READ(UNIT=7) (MAT (I),I=1,NTERMS)
        CLOSE(UNIT=7)
C
        WRITE(6,170)
  170   FORMAT( ' DO YOU WANT THE PATHS RESTORED? ',$)
        READ(5,40) NC,INPUT
        IF(INDEX(INPUT(1:NC),'Y').NE.0) SAVE=1
C       SPECIAL CASE TO PRINT ALL PATHS
        IF(INDEX(INPUT(1:NC),'YES SOLUTIONS').NE.0) GO TO 240
C
C       MAZE DESCRIPTION
C
  180   WRITE(6,190) HEIGHT,WIDTH,DEPTH
  190   FORMAT('0',' YOUR MAZE HAS A HEIGHT OF',I5,/,
        1  '             AND A WIDTH OF',I5,/,
        1  '            WITH A DEPTH OF',I5,//,
        2  '  THE DIRECTION COMMANDS FOR MAZE ARE SINGLE LETTERS',/,
        2  '    N(ORTH), U(P),    OR 8 IS UP',/,
        2  '    E(AST) , R(IGHT), OR 6 IS RIGHT',/,
        2  '    S(OUTH), D(OWN),  OR 2 IS DOWN',/,
        2  '    W(EST) , L(EFT),  OR 4 IS LEFT',/,
        2  '    I(N)   ,          OR 9 IS IN TO SCREEN',/,
        2  '    O(UT)  ,          OR 7 IS OUT OF SCREEN',/,
        2  '  OR YOU CAN USE THE ARROW KEYS FOR DIRECTIONS',/,
        3  '  THE COMMAND H(OME)    RETURNS YOUR POSITION TO "S" OR "O"',/,
        3  '  THE COMMAND Q(UIT)    ENDS THE GAME',/,
        3  '  THE COMMAND B(ELL)    MAKES THE TERMINAL BEEP (DEFAULT)',/,
        3  '  THE COMMAND M(UTE)    TURNS OFF TERMINAL BEEPING',/,
        3  '  THE COMMAND C(URRENT) PRINTS THE CURRENT LEVEL',/,
        3  '  AFTER A Q(UIT) COMMAND YOU GET A CHANCE TO SAVE THE GAME',/,
        4  '  YOU CAN MOVE ALONG BORDERS',//,
        4  '  PRESS RETURN TO START')
        READ(5,40) NC,INPUT
        NOBELL = 0
        IF(INPUT(1:6).EQ.'NOBELL') OFFBEL = 1
C
C       EXECUTE THE MAZE
C
        IF(SAVE.EQ.1) GO TO 210
        DO 200 I=1,NTERMS
  200   MAT(I)=0
C
  210   CALL MAZRUN(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
C
C       SAVE THE MAZE ON REQUEST
C
        WRITE(6,220)
  220   FORMAT(' DO YOU WANT TO SAVE THIS MAZE? ',$)
        READ(5,40) NC,INPUT
C
        IF(INDEX(INPUT(1:NC),'Y') .EQ.0) GO TO 260
        WRITE(6,230)
  230   FORMAT(' PLEASE INPUT FILE NAME ',$)
        READ(5,40) NC,INPUT
        OPEN(UNIT=7,NAME=INPUT(1:NC),STATUS='NEW',FORM='UNFORMATTED')
        WRITE(UNIT=7) HEIGHT,WIDTH,DEPTH,STARTH,STARTW,STARTD,
        1 ENDH,ENDW,ENDD
        WRITE(UNIT=7) (EXIT(I),I=1,NTERMS)
        WRITE(UNIT=7) (MAT (I),I=1,NTERMS)
        CLOSE(UNIT=7)
        GO TO 260
C
C       PRINT THE SOLUTION TO A MAZE
C
  240   WRITE(6,250) HEIGHT,WIDTH,DEPTH
  250   FORMAT('0',' YOUR MAZE HAS A HEIGHT OF',I5,/,
        1  '             AND A WIDTH OF',I5,/,
        1  '            WITH A DEPTH OF',I5,//,
        4  '  PRESS RETURN TO START')
        READ(5,40) NC,INPUT
C
C       PRINT MAZE
C
        CALL MAZSOL(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
C
C       CLEAR SCREEN AND WAIT 2 SECONDS
C
  260   CALL MAZOUT(CLEAR,2,1,24,1,0,0,0)
        CALL SYS$BINTIM( '0 ::02.00', SLEEP )
        CALL SYS$SCHDWK( , , SLEEP , )
        CALL SYS$HIBER
        STOP 'BYE FROM MAZE'
        END
 
        SUBROUTINE MAZGEN (  EXIT, LCOUNT, HEIGHT, WIDTH, DEPTH )
C
C       MAZGEN CREATES A MAZE IN EXIT
C
C       MAZE IS CREATED BY GOING FROM A START LOCATION IN A
C       RANDOM WALK
C       SQUARES MAY ONLY BE ENTERED ONCE BUT CAN HAVE MULTIPLE EXITS
C
C       MOVEMENT CONVENTION IS
C               1 - SOUTH OR DOWN
C               2 - EAST  OR RIGHT
C               4 - NORTH OR UP
C               8 - WEST  OR LEFT
C              16 - IN  A LEVEL
C              32 - OUT A LEVEL
C
        IMPLICIT INTEGER*4 (A-Z)
C
        INTEGER*2  EXIT(HEIGHT,WIDTH,DEPTH), LCOUNT(DEPTH)
C
        DIMENSION XDIR(4), YDIR(4), IN(4), OUT(4)
C
        REAL  SEED
C
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
C
        DATA XDIR / 0, 1, 0,-1 /
        DATA YDIR / 1, 0,-1, 0 /
        DATA IN   / 4, 8, 1, 2 /
        DATA OUT  / 1, 2, 4, 8 /
C
C       INITIALIZE AND PICK START AND END POSITIONS
C
        SEED = FOR$SECNDS(0)
        H = HEIGHT
        W = WIDTH
        D = DEPTH
        NENTER = 1
        LMAX = H * W
        NMAX = LMAX * D
        DO 10 L=1,D
        LCOUNT(L) = 0
        DO 10 J=1,W
        DO 10 I=1,H
   10   EXIT (I,J,L) = 0
C
        STARTH = IRAN(SEED,1,H)
        STARTW = IRAN(SEED,1,W)
        STARTD = 1
   20   ENDH   = IRAN(SEED,1,H)
        ENDW   = IRAN(SEED,1,W)
        ENDD   = D
        IF(STARTH.EQ.ENDH.AND.STARTW.EQ.ENDW.AND.STARTD.EQ.ENDD)
        1 GO TO 20
        SY = STARTH
        SX = STARTW
        SD = STARTD
        LCOUNT(SD) = 1
C
C       START FILLING IN MAZE
C
   30   ODIR = 0
        Y = SY
        X = SX
        L = SD
   40   DIR = IRAN(SEED,1,4)
C       DO NOT GO BACK ON YOURSELF
        IF( ODIR .EQ. OUT(DIR) ) GO TO 40
C
C       TEND TO MAKE LONGER LINES WITH NLOOPS
C
        NLOOPS = IRAN(SEED,1,DIR)
        NCOUNT=0
   50   NY = YDIR(DIR) + Y
        NX = XDIR(DIR) + X
        IF(NY.LT.1.OR.NY.GT.H) GO TO 40
        IF(NX.LT.1.OR.NX.GT.W) GO TO 40
        IF( EXIT(NY,NX,L) .EQ. 0 ) GO TO 80
C
C       CHECK FOR DEAD END
C
        DO 60 I=1,4
        TY = Y + YDIR(I)
        TX = X + XDIR(I)
        IF(TY.LT.1.OR.TY.GT.H) GO TO 60
        IF(TX.LT.1.OR.TX.GT.W) GO TO 60
C       NOT DEAD END TRY AGAIN
        IF( EXIT(TY,TX,L) .NE. 0 ) GO TO 60
        GO TO 40
   60   CONTINUE
C
C       DEAD END RETURN TO START UNLESS ALL DIRECTIONS ARE TAKEN
C
        IF( Y.EQ.SY .AND. X.EQ. SX ) GO TO 70
        GO TO 30
C
C       ALL STARTS FROM THIS STARTING POSITION ARE TAKEN
C       PICK A NEW STARTING POSITIONS UNTIL MAZE IS FULL
C
   70   SY = IRAN(SEED,1,H)
        SX = IRAN(SEED,1,W)
        IF( EXIT(SY,SX,L) .EQ. 0 ) GO TO 70
        IF( SY.EQ.STARTH.AND.SX.EQ.STARTW.AND.L.EQ.STARTD) GO TO 70
        IF( SY.EQ.ENDH  .AND.SX.EQ.ENDW  .AND.L.EQ.ENDD) GO TO 70
        IF( SY.EQ.Y     .AND.SX.EQ.X   ) GO TO 70
C
C       FILL IN A LAYER AT A TIME
C
        IF(LCOUNT(L).NE.LMAX) GO TO 30
        SD = SD + 1
        EXIT(SY,SX, L) = IOR(EXIT(SY,SX, L),16)
        EXIT(SY,SX,SD) = IOR(EXIT(SY,SX,SD),32)
        NENTER = NENTER + 1
        LCOUNT(SD) = 1
        GO TO 30
C
C       DIRECTION TO GO FOUND
C       SET POSITION AS HAVING BEEN ENTERED AND
C       SET EXIT ARRAY TO DIRECTIONS INVOLVED
C
   80   ODIR = IN(DIR)
        EXIT(Y,X,L)   = IOR(EXIT(Y,X,L),OUT(DIR))
        EXIT(NY,NX,L) = IOR(EXIT(NY,NX,L),IN(DIR))
        NENTER = NENTER + 1
        LCOUNT(L) = LCOUNT(L)+1
C       THE WAY OUT - ALL POINTS USED
        IF( NENTER .EQ. NMAX ) GO TO 90
        Y = NY
        X = NX
C
C       ONLY ALLOW THE END LOCATION TO BE ENTERED ONCE
C
        IF(Y.EQ.ENDH.AND.X.EQ.ENDW.AND.L.EQ.ENDD) GO TO 30
        NCOUNT=NCOUNT+1
        IF(NCOUNT.LT.NLOOPS) GO TO 50
        GO TO 40
C
C       OUT
C
   90   CONTINUE
        RETURN
        END
 
        SUBROUTINE MAZOUT( STRING, L, XOFF, Y, X, BOLD, REVERS, BLINK )
C*****
C  OUTPUTS -STRING- OF LENGTH -L- BYTES WITH BYTE NUMBER -XOFF-
C  OF STRING LOCATED AT CURSER LOCATION -X-, -Y-.
C
C  BOLD, REVERS, BLINK ARE THE MODES TO OUTPUT THIS STRING
C*****
        IMPLICIT INTEGER*2 (A-Z)
C
        LOGICAL ANY
C
        CHARACTER*300 CC
C
        BYTE STRING(L), LINEOUT(300), CHAR(10), ESCAPE
C
        DATA CHAR/ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' /
        DATA ESCAPE/ 27 /, C1,C2,C3 / 0,0,0/
C
        EQUIVALENCE(CC,LINEOUT(1))
C
        NL     = X - XOFF + 1
        NR     = NL + L - 1
        LENGTH = L
        ISTART = 1
        NX     = X
        NY     = Y
C
C  READJUST STRING LIMITS TO BE WITHIN SCREEN.  IF STRING IS
C  COMPLETELY OUT OF SCREEN, THEN RETURN DOING NOTHING.
C
        IF( NY.LT.1 .OR. NY.GT.24 ) RETURN
        IF( NR.LT.1 .OR. NL.GT.132 ) RETURN
C
C  STRING (ALL OR PART) LIES IN THE SCREEN AREA.
C
        IF( NL .GE. 1 ) GO TO 10
        ISTART = 2 - NL
        NL     = 1
        LENGTH = LENGTH - ISTART + 1
C
   10 IF( NR .LE. 132 ) GO TO 20
        LENGTH = LENGTH - (NR-132)
        NR = 132
C
C  OK AT THIS POINT WE ARE GOING TO OUTPUT STRING(ISTART) THRU
C  STRING(ISTART+LENGTH-1) STARTING AT SCREEN LOCAT SCREEN ION (NL,NY)
C
C 20  LINEOUT(1) = ' '
   20 LINEOUT(1) = ESCAPE
        LINEOUT(2) = '['
        IOUT = 2
        COORD = NY
        DO 40 I = 1,2
        ANY = .FALSE.
        DO 30 J = 1,3
        N = MOD( COORD/10**(3-J), 10 )
        IF( N.EQ.0 .AND. .NOT.ANY ) GO TO 30
        ANY = .TRUE.
        IOUT = IOUT + 1
        LINEOUT(IOUT) = CHAR(N+1)
   30 CONTINUE
        IOUT = IOUT + 1
        LINEOUT(IOUT) = ';'
        COORD = NL
   40 CONTINUE
        LINEOUT(IOUT) = 'H'
C
C  CHECK MODES AGAINST CURRENT MODES AND OUTPUT APPROPRIATE
C  MODE INDICATORS.
C
        IF( C1.NE.0 .AND.   BOLD.EQ.0 ) GO TO 80
        IF( C2.NE.0 .AND. REVERS.EQ.0 ) GO TO 80
        IF( C3.NE.0 .AND.  BLINK.EQ.0 ) GO TO 80
        IF( C1.EQ.BOLD .AND. C2.EQ.REVERS .AND. C3.EQ.BLINK )GO TO 120
C
C  OK SIMPLY ADD OUTPUT MODES
C
        LINEOUT(IOUT+1) = ESCAPE
        LINEOUT(IOUT+2) = '['
        IOUT = IOUT + 2
C
        IF( C1.EQ.BOLD   ) GO TO 50
        LINEOUT(IOUT+1) = '1'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
        C1   = BOLD
C
   50 IF( C2 .EQ. REVERS ) GO TO 60
        LINEOUT(IOUT+1) = '7'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
        C2 = REVERS
C
   60 IF( C3 .EQ. BLINK ) GO TO 70
        LINEOUT(IOUT+1) = '5'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
        C3 = BLINK
C
   70 LINEOUT(IOUT) = 'm'
        GO TO 120
C
C  SOME OR ALL OF CURRENT MODES ARE NOT DESIRED, THUS
C  MUST DO A NORMAL FOLLOWED BY A RESET OF MODES DESIRED.
C
   80 LINEOUT(IOUT+1) = ESCAPE
        LINEOUT(IOUT+2) = '['
        LINEOUT(IOUT+3) = '0'
        LINEOUT(IOUT+4) = ';'
        IOUT = IOUT + 4
C
        IF( BOLD .EQ. 0 ) GO TO 90
        LINEOUT(IOUT+1) = '1'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
C
   90 C1 = BOLD
        IF( REVERS .EQ. 0 ) GO TO 100
        LINEOUT(IOUT+1) = '7'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
C
  100 C2 = REVERS
        IF( BLINK .EQ. 0 ) GO TO 110
        LINEOUT(IOUT+1) = '5'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
C
  110 C3 = BLINK
        LINEOUT(IOUT) = 'm'
C*****
C  OUTPUT THE STRING WITH ITS LEADER
C*****
  120 DO 130 I = 1,LENGTH
        LINEOUT(IOUT+I) = STRING(ISTART+I-1)
  130 CONTINUE
        IOUT = IOUT + LENGTH
C*****
C  BACK UP CURSER ONE LINE IF AT LINE 24
C*****
        IF( NY .NE. 24 ) GO TO 140
        LINEOUT(IOUT+1) = ESCAPE
        LINEOUT(IOUT+2) = 'M'
        IOUT = IOUT + 2
C*****
C  NOW READY TO OUTPUT THE STRING.
C*****
  140 RC = LIB$PUT_OUTPUT( CC(1:IOUT) )
        RETURN
        END
        FUNCTION IRAN( SEED, I, J )
C*****
C  RETURNS A RANDOM NUMBER IN THE RANGE OF I THRU J.
C  SEED IS UPDATED AND THUS A VARIABLE MUST BE SENT.
C*****
        REAL MTH$RANDOM
        FN = J - I + 1
        IRAN = I + IFIX( FN * MTH$RANDOM(SEED) )
        RETURN
        END
 
        SUBROUTINE MAZRUN(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
C
C       MAZRUN USES THE EXIT ARRAY TO CONTROL MAZE MOVEMENT
C                       MAT  ARRAY CONTAINS WHERE YOU HAVE BEEN
C
        IMPLICIT INTEGER*4 (A-Z)
C
        INTEGER*2 EXIT(HEIGHT,WIDTH,DEPTH)
        INTEGER*2 MAT (HEIGHT,WIDTH,DEPTH), ADD, MOVE(4,4)
C
        DIMENSION XDIR(4), YDIR(4), OUT(6), SLEEP(2)
C
        BYTE START(28),BELL,DEAD,LR132(10)
        BYTE SET(16)
        BYTE SCROL(8)
C
        CHARACTER*200 INPUT
        CHARACTER*10  NAME
        CHARACTER*6   PORT
C
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
C
        DATA XDIR / 0, 1, 0,-1 /
        DATA YDIR / 1, 0,-1, 0 /
        DATA OUT  / 1, 2, 4, 8, 16, 32 /
        DATA BELL / 7 /
C
C       ESCAPE SEQUENCES TO
C       ANSI MODE, ERASE SCREEN, ATTRIBUTES OFF, SCREEN NORMAL,
C       WRAP OFF, 80 COL., AND SPECIAL GRAPHICS
C
        DATA START/ 27,'<',27,'[','2','J',27,'[','0','m',27,'[','?',
     1    '5','l',27,'[','?','7','l',  27,'[','?','3','l',27,'(','0'/
C
C       GRAPHICS CHARACTERS TO USE FOR DRAWING LINES
C
        DATA SET/' ', ' ', 'l', ' ', 'k', 'q', 'w', ' ',
     1     'x', 'm', 't', 'j', 'u', 'v', 'n', 97 /
C
C       ESCAPE SEQUENCE TO SET 132 CHARACTER LINE MODE
C
        DATA LR132 / 27,'[','?','3','h' , 27,'[','?','5','h' /
C
C       SET SCROLLING REGION TO LAST TWO LINES (23-24)
C
        DATA SCROL / 27,'[','2','3',';','2','4','r' /
        DATA DEAD / 97 /
        DATA MOVE / 9, 5,-1, 3
        1        ,10, 6, 3,-1
        2        ,-1,12, 9,10
        3        ,12,-1, 5, 6 /
C
C       SET UP FOR QIO FROM TERMINAL
C
        STATUS = SYS$TRNLOG( 'SYS$INPUT' ,, NAME ,,, )
        PORT = NAME( 5:10 )
        STATUS = SYS$ASSIGN( PORT, CHAN ,, )
        IF( STATUS.NE.1 ) RETURN
        READ = 49
        NOECHO = 64
        CVLOW = 256
C
C       CLEAR SCREEN AND SHOW START AND END OF MAZE
C
        CALL MAZOUT( START(1), 28, 1, 1,1, 0,0,0)
        IF(WIDTH.GT.80) CALL MAZOUT(LR132,10,1,1,1,0,0,0)
        CALL MAZOUT(SCROL,8,1,23,1,0,0,0)
        LOOP = 0
        SOVER = 0
C
C       BORDER
C
   10   CONTINUE
        Y = STARTH
        X = STARTW
        L = STARTD
   20   CONTINUE
        CALL MAZOUT(START(3),4,1,1,1,0,0,0)
        DO 40 I=1,HEIGHT
        CALL MAZOUT(' ',1,1, I,1     ,0,1,0)
        CALL MAZOUT(' ',1,1, I,WIDTH,0,1,0)
        IF(I.NE.1.AND.I.NE.HEIGHT) GO TO 40
        DO 30 J=2,WIDTH-1
        CALL MAZOUT(' ',1,1, I,J     ,0,1,0)
   30   CONTINUE
   40   CONTINUE
C
C       SHOW CURRENT STATUS OF MAZE SOLUTION
C
        DO 50 J=1,WIDTH
        DO 50 I=1,HEIGHT
        IF(IAND(EXIT(I,J,L),16).NE.0) CALL MAZOUT('O',1,1,I,J,1,1,1)
        IF(MAT(I,J,L).EQ.0) GO TO 50
        IF(MAT(I,J,L).GT.0.AND.MAT(I,J,L).LT.16)
        1 CALL MAZOUT(SET(MAT(I,J,L)),1,1,I,J,1,1,0)
        IF(MAT(I,J,L).LT.0) CALL MAZOUT('~',1,1,I,J,1,1,0)
        IF(MAT(I,J,L).EQ.64) CALL MAZOUT(SET(16),1,1,I,J,1,1,0)
        IF(MAT(I,J,L).GT.15.AND.MAT(I,J,L).LT.32)
        1 CALL MAZOUT('O',1,1,I,J,1,1,0)
        IF(MAT(I,J,L).GT.31.AND.MAT(I,J,L).LT.64)
        1 CALL MAZOUT('O',1,1,I,J,1,1,1)
   50   CONTINUE
        IF(LOOP.NE.0) CALL MAZOUT('O',1,1,Y,X,0,1,0)
        IF(L.EQ.ENDD) CALL MAZOUT( 'E',1,1,ENDH,ENDW,1,1,1)
        IF(L.EQ.STARTD) CALL MAZOUT( 'S',1,1,STARTH,STARTW,1,1,1)
        HOMEH = Y
        HOMEW = X
   60   DEADE = 0
        ODIR = 0
C
C       READ INPUT AND MOVE AS REQUESTED
C
        ESC = 0
        OPT =  READ + NOECHO + CVLOW
   70   CALL MAZOUT(' ',1,1,24,1,0,0,0)
C
        STATUS = SYS$QIOW( , %VAL(CHAN), %VAL(OPT),,,,
        1       %VAL(%LOC(INPUT)), %VAL(1),,,, )
        IF( STATUS .NE. 1 ) RETURN
C
   80   FORMAT(Q,A)
        IF( ESC .EQ. 1 ) GO TO 140
        IF(ICHAR(INPUT(1:1)) .EQ. 27 ) GO TO 130
        IF(INPUT(1:1) .EQ.'Q') RETURN
        IF(INPUT(1:1) .EQ.'B') GO TO 90
        IF(INPUT(1:1) .EQ.'M') GO TO 100
        IF(INPUT(1:1) .EQ.'C' ) GO TO 110
        IF(INPUT(1:1).NE.'H') GO TO 160
        IF(Y.EQ.HOMEH.AND.X.EQ.HOMEW) GO TO 60
        SOVER=1
        ADD = -1
        GO TO 220
   90   NOBELL = 0
        GO TO 70
  100   NOBELL = 1
        GO TO 70
  110   WRITE(6,120) L
  120   FORMAT( ' CURRENT LEVEL IS ',I2)
        GO TO 70
  130   ESC = 1
        GO TO 70
  140   IF(INPUT(1:1) .EQ. '[' ) GO TO 70
        GO TO 170
  150   SOVER = 0
        Y = HOMEH
        X = HOMEW
        GO TO 60
C
C       FIND DIRECTION TO GO
C
  160   DIR = 0
        IF(ICHAR(INPUT(1:1)).EQ.27) GO TO 170
        IF(INPUT(1:1).EQ.'S'.OR.INPUT(1:1).EQ.'D') DIR=1
        IF(INPUT(1:1).EQ.'E'.OR.INPUT(1:1).EQ.'R') DIR=2
        IF(INPUT(1:1).EQ.'N'.OR.INPUT(1:1).EQ.'U') DIR=3
        IF(INPUT(1:1).EQ.'W'.OR.INPUT(1:1).EQ.'L') DIR=4
        IF(INPUT(1:1).EQ.'2') DIR=1
        IF(INPUT(1:1).EQ.'6') DIR=2
        IF(INPUT(1:1).EQ.'8') DIR=3
        IF(INPUT(1:1).EQ.'4') DIR=4
        IF(INPUT(1:1).EQ.'I'.OR.INPUT(1:1).EQ.'9') DIR=5
        IF(INPUT(1:1).EQ.'O'.OR.INPUT(1:1).EQ.'7') DIR=6
        GO TO 180
C
C       CHECK ARROW KEYS ( DID NOT HAVE TIME TO MAKE THIS WORK )
C
  170   IF(INPUT(1:1).EQ.'A') DIR=3
        IF(INPUT(1:1).EQ.'B') DIR=1
        IF(INPUT(1:1).EQ.'C') DIR=2
        IF(INPUT(1:1).EQ.'D') DIR=4
        ESC = 0
  180   IF(DIR.NE.0) GO TO 200
C
C       COMMAND NOT RECOGNIZED
C
        WRITE(6,190)
  190   FORMAT(' TRY AGAIN ')
        GO TO 70
C
C       SEE IF DIRECTION IS LEGAL
C
  200   IF( IAND(EXIT(Y,X,L),OUT(DIR)) .NE. 0 ) GO TO 210
        IF(NOBELL .NE. 0 ) GO TO 70
        CALL MAZOUT( BELL ,1,1, 24,1, 0,0,0 )
        GO TO 70
C
C       MOVE KEEP MOVEMENT ARRAY MAT UP TO DATE
C
  210   IF(Y.EQ.STARTH.AND.X.EQ.STARTW.AND.L.EQ.STARTD) GO TO 230
        IF(DEADE.EQ.1) GO TO 230
        ADD = OUT(DIR)
        IF(ODIR.NE.0.AND.DIR.LT.5) ADD = MOVE(ODIR,DIR)
        IF(ODIR.EQ.0) ADD = 0
  220   IF(MAT(Y,X,L).EQ.-1) MAT(Y,X,L) = 0
        IF(ADD.EQ.-1 .AND. MAT(Y,X,L).EQ.0 ) MAT(Y,X,L) = ADD
        IF(ADD.NE.-1) MAT(Y,X,L) = IOR(MAT(Y,X,L),ADD)
        IF(MAT(Y,X,L).GT.0.AND.MAT(Y,X,L).LT.16)
        1 CALL MAZOUT(SET(MAT(Y,X,L)),1,1,Y,X,1,1,0)
        IF(MAT(Y,X,L).LT.0) CALL MAZOUT( '~' ,1,1,Y,X,1,1,0)
  230   IF(SOVER.EQ.1) GO TO 150
        IF( DIR.LT.5 ) GO TO 240
C
C       CHANGE LEVELS
C
        IF( DIR.EQ.5 ) L = L+1
        IF( DIR.EQ.6 ) L = L-1
        MAT(Y,X,L) = OUT(DIR)
        LOOP = LOOP + 1
        GO TO 20
  240   Y = Y + YDIR(DIR)
        X = X + XDIR(DIR)
        IF(Y.EQ.STARTH.AND.X.EQ.STARTW.AND.L.EQ.STARTD) GO TO 70
        IF(MAT(Y,X,L).LT.16) CALL MAZOUT('{',1,1,Y,X,0,1,1)
        DEADE = 0
        ODIR = DIR
        IF(Y.EQ.ENDH.AND.X.EQ.ENDW.AND.L.EQ.ENDD) GO TO 270
C
C       CHECK FOR DEAD END
C
        DO 250 I=1,6
        IF( EXIT(Y,X,L) .EQ. OUT(I) ) GO TO 260
  250   CONTINUE
        GO TO 70
C
C       DEAD END
C
  260   CALL MAZOUT(DEAD,1,1,Y,X,0,0,0)
        MAT(Y,X,L) = 64
        DEADE = 1
        GO TO 70
  270   CONTINUE
C
C       SUCCESS - END FOUND
C
        DO 290 I=1,6
        J=MOD(I,2)
        CALL MAZOUT('E',1,1,ENDH,ENDW,1,J,1)
        CALL MAZOUT(' ',1,1,24,1,0,J,1)
        WRITE(6,280)
  280   FORMAT(' SUCCESS SUCCESS SUCCESS' )
        CALL SYS$BINTIM( '0 ::00.50', SLEEP )
        CALL SYS$SCHDWK( , , SLEEP , )
        CALL SYS$HIBER
  290   CONTINUE
        RETURN
        END
 
        SUBROUTINE MAZSOL(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
C
C       MAZSOL SHOWS ALL POSSIABLE PATHS IN MAZE
C
        IMPLICIT INTEGER*4 (A-Z)
C
        INTEGER*2 EXIT(HEIGHT,WIDTH,DEPTH)
        INTEGER*2 MAT (HEIGHT,WIDTH,DEPTH), ADD, MOVE(4,4)
        DIMENSION XDIR(4), YDIR(4), OUT(4), SLEEP(2)
C
        BYTE START(28),BELL,DEAD,LR132(10)
        BYTE SET(16)
        BYTE SCROL(8)
C
        CHARACTER*200 INPUT
C
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
C
        DATA XDIR / 0, 1, 0,-1 /
        DATA YDIR / 1, 0,-1, 0 /
        DATA OUT  / 1, 2, 4, 8 /
        DATA BELL / 7 /
        DATA START/ 27,'<',27,'[','2','J',27,'[','0','m',27,'[','?',
     1    '5','l',27,'[','?','7','l',  27,'[','?','3','l',27,'(','0'/
        DATA SET/' ', ' ', 'l', ' ', 'k', 'q', 'w', ' ',
     1     'x', 'm', 't', 'j', 'u', 'v', 'n', 97 /
        DATA LR132 / 27,'[','?','3','h' , 27,'[','?','5','h' /
        DATA SCROL / 27,'[','2','3',';','2','4','r' /
        DATA DEAD / 97 /
        DATA MOVE / 0, 3, 9, 5
        1        , 3, 0,10, 6
        2        , 9,10, 0,12
        3        , 5, 6,12, 0 /
C
C       CLEAR SCREEN AND SHOW START AND END OF MAZE
C
        CALL MAZOUT( START(1), 28, 1, 1,1, 0,0,0)
        IF(WIDTH.GT.80) CALL MAZOUT(LR132,10,1,1,1,0,0,0)
        CALL MAZOUT(SCROL,8,1,23,1,0,0,0)
C
C       BORDER
C
        DO 70 L = 1,DEPTH
        IF(L.EQ.ENDD) CALL MAZOUT( 'E',1,1,ENDH,ENDW,1,1,1)
        IF(L.EQ.STARTD) CALL MAZOUT( 'S',1,1,STARTH,STARTW,1,1,1)
C
C       LOOP OVER MAZE
C
        DO 40 X=1,WIDTH
        DO 40 Y=1,HEIGHT
        MAT(Y,X,L) = 0
        IF(Y.EQ.STARTH.AND.X.EQ.STARTW.AND.L.EQ.STARTD) GO TO 40
        IF(Y.EQ.ENDH  .AND.X.EQ.ENDW  .AND.L.EQ.ENDD) GO TO 40
C
C       CHECK FOR DEAD END
C
        DO 20 ODIR=1,4
        IF( EXIT(Y,X,L) .EQ. OUT(ODIR) ) GO TO 30
        IF( IAND(EXIT(Y,X,L),OUT(ODIR)) .EQ. 0 ) GO TO 20
        DO 10 DIR=1,4
        IF(DIR.EQ.ODIR) GO TO 10
        IF( IAND(EXIT(Y,X,L),OUT(DIR)) .EQ. 0 ) GO TO 10
        ADD = MOVE(ODIR,DIR)
        MAT(Y,X,L) = IOR(MAT(Y,X,L),ADD)
   10   CONTINUE
   20   CONTINUE
        IF(EXIT(Y,X,L).LT.16) CALL MAZOUT(SET(MAT(Y,X,L)),1,1,Y,X,1,1,0)
        IF(IAND(EXIT(Y,X,L),16).NE.0) CALL MAZOUT('O',1,1,Y,X,1,1,1)
        IF(IAND(EXIT(Y,X,L),32).NE.0) CALL MAZOUT('O',1,1,Y,X,1,1,0)
        GO TO 40
C
C       DEAD END
C
   30   CALL MAZOUT(DEAD,1,1,Y,X,0,0,0)
   40   CONTINUE
C
C       SUCCESS - END FOUND
C
        CALL MAZOUT(' ',1,1,24,1,0,0,0)
        WRITE(6,50)
   50   FORMAT('  PRESS RETURN TO CONTINUE OR FINISH')
        READ(5,60) NC,INPUT
   60   FORMAT(Q,A)
   70   CONTINUE
        RETURN
        END

//
//      MAZE -  USES A VT100 TO WANDER AROUND.
//              THE VT100 MUST HAVE ADVANCED VIDEO OPTION.
//              ANSI VT100 ESCAPE SEQUENCES ARE USED.
//
//      WRITTEN BY DON MCLEAN
//      OF THE MACNEAL-SCHWENDLER CORP.
//
//      THE PURPOSE OF THIS PROGRAM WAS TO
//              1. LEARN SOMETHING ABOUT THE VT100 GRAPHICS.
//              2. KEEP MY KIDS BUSY ON WEEKENDS. WHILE I TRIED
//                 TO GET SOMETHING ELSE DONE.
//
//      USE OF THIS PROGRAM FOR ANY PURPOSE OTHER THAN FUN
//      IS PROHIBITED.
//
        IMPLICIT INTEGER*4 (A-Z)
//
//      MAZE DIMENSIONS
//      HMAX AND WMAX SHOULD NOT BE LARGER THAN 22 AND 80 RESP.
//
        PARAMETER HMAX=22, WMAX=80, DMAX=4
//
        DIMENSION SLEEP(2)
//
//      DIMENSION IS HMAX*WMAX*DMAX
        INTEGER*2  EXIT(HMAX*WMAX*DMAX), MAT(HMAX*WMAX*DMAX)
        INTEGER*2  LCOUNT(DMAX)
//
        BYTE CLEAR(2)
//
        CHARACTER*200 INPUT
//
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
//
//      CLEAR IS A VT100 RESET
//
        DATA CLEAR / 27, 'c' /
//
//      START - SEE IF AN OLD GAME IS TO BE USED.
//
        WRITE(6,10)
   10   FORMAT(' WELCOME TO MAZE')
//
   20   WRITE(6,30)
   30   FORMAT(' ARE YOU GOING TO PLAY A SAVED GAME? ',$)
        READ(5,40) NC,INPUT
   40   FORMAT(Q,A)
        IF(INDEX(INPUT(1:NC),'Y').NE.0) GO TO 120
        SAVE = 0
//
//      INPUT DIMENSION OF MAZE
//
   50   WRITE(6,60) HMAX
   60   FORMAT(' PLEASE INPUT HEIGHT OF MAZE - DEFAULT = ',I2,' ',$)
        READ(5,40) NC,INPUT
        READ(INPUT,70,ERR=50) HEIGHT
   70   FORMAT(BNI2)
        IF(HEIGHT.EQ.0) HEIGHT=HMAX
        IF(HEIGHT.LT.2) HEIGHT=2
        IF(HEIGHT.GT.HMAX) HEIGHT=HMAX
   80   WRITE(6,90) WMAX
   90   FORMAT(' PLEASE INPUT WIDTH  OF MAZE - DEFAULT = ',I2,' ',$)
        READ(5,40) NC,INPUT
        READ(INPUT,70,ERR=80) WIDTH
        IF(WIDTH.EQ.0) WIDTH = WMAX
        IF(WIDTH.LT.2) WIDTH=2
        IF(WIDTH.GT.WMAX) WIDTH=WMAX
  100   WRITE(6,110)
  110   FORMAT(' PLEASE INPUT DEPTH  OF MAZE - DEFAULT =  1 ',$)
        READ(5,40) NC,INPUT
        READ(INPUT,70,ERR=100) DEPTH
        IF(DEPTH.LE.0) DEPTH = 1
        IF(DEPTH.GT.DMAX) DEPTH = DMAX
        NTERMS = HEIGHT * WIDTH * DEPTH
//
//      GENERATE MAZE
//
        CALL MAZGEN(EXIT,LCOUNT,HEIGHT,WIDTH,DEPTH)
        GO TO 180
//
//      READ IN OLD MAZE
//
  120   WRITE(6,130)
  130   FORMAT(' INPUT SAVED FILE NAME ',$)
        READ(5,40) NC,INPUT
        OPEN(UNIT=7,NAME=INPUT(1:NC),STATUS='OLD',ERR=140,FORM='UNFORMATTED',READONLY)
        GO TO 160
//
  140   WRITE(6,150)
  150   FORMAT(' SAVE FILE NOT FOUND')
        GO TO 20
  160   READ(UNIT=7) HEIGHT,WIDTH,DEPTH,STARTH,STARTW,STARTD,ENDH,ENDW,ENDD
        NTERMS = HEIGHT * WIDTH * DEPTH
        READ(UNIT=7) (EXIT(I),I=1,NTERMS)
        READ(UNIT=7) (MAT (I),I=1,NTERMS)
        CLOSE(UNIT=7)
//
        WRITE(6,170)
  170   FORMAT( ' DO YOU WANT THE PATHS RESTORED? ',$)
        READ(5,40) NC,INPUT
        IF(INDEX(INPUT(1:NC),'Y').NE.0) SAVE=1
//      SPECIAL CASE TO PRINT ALL PATHS
        IF(INDEX(INPUT(1:NC),'YES SOLUTIONS').NE.0) GO TO 240
//
//      MAZE DESCRIPTION
//
  180   WRITE(6,190) HEIGHT,WIDTH,DEPTH
  190   FORMAT('0',' YOUR MAZE HAS A HEIGHT OF',I5,/,'             AND A WIDTH OF',I5,/,'            WITH A DEPTH OF',I5,//,'  THE DIRECTION COMMANDS FOR MAZE ARE SINGLE LETTERS',/,'    N(ORTH), U(P),    OR 8 IS UP',/,'    E(AST) , R(IGHT), OR 6 IS RIGHT',/,'    S(OUTH), D(OWN),  OR 2 IS DOWN',/,'    W(EST) , L(EFT),  OR 4 IS LEFT',/,'    I(N)   ,          OR 9 IS IN TO SCREEN',/,'    O(UT)  ,          OR 7 IS OUT OF SCREEN',/,'  OR YOU CAN USE THE ARROW KEYS FOR DIRECTIONS',/,'  THE COMMAND H(OME)    RETURNS YOUR POSITION TO "S" OR "O"',/,'  THE COMMAND Q(UIT)    ENDS THE GAME',/,'  THE COMMAND B(ELL)    MAKES THE TERMINAL BEEP (DEFAULT)',/,'  THE COMMAND M(UTE)    TURNS OFF TERMINAL BEEPING',/,'  THE COMMAND C(URRENT) PRINTS THE CURRENT LEVEL',/,'  AFTER A Q(UIT) COMMAND YOU GET A CHANCE TO SAVE THE GAME',/,'  YOU CAN MOVE ALONG BORDERS',//,'  PRESS RETURN TO START')
        READ(5,40) NC,INPUT
        NOBELL = 0
        IF(INPUT(1:6).EQ.'NOBELL') OFFBEL = 1
//
//      EXECUTE THE MAZE
//
        IF(SAVE.EQ.1) GO TO 210
        DO 200 I=1,NTERMS
  200   MAT(I)=0
//
  210   CALL MAZRUN(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
//
//      SAVE THE MAZE ON REQUEST
//
        WRITE(6,220)
  220   FORMAT(' DO YOU WANT TO SAVE THIS MAZE? ',$)
        READ(5,40) NC,INPUT
//
        IF(INDEX(INPUT(1:NC),'Y') .EQ.0) GO TO 260
        WRITE(6,230)
  230   FORMAT(' PLEASE INPUT FILE NAME ',$)
        READ(5,40) NC,INPUT
        OPEN(UNIT=7,NAME=INPUT(1:NC),STATUS='NEW',FORM='UNFORMATTED')
        WRITE(UNIT=7) HEIGHT,WIDTH,DEPTH,STARTH,STARTW,STARTD,ENDH,ENDW,ENDD
        WRITE(UNIT=7) (EXIT(I),I=1,NTERMS)
        WRITE(UNIT=7) (MAT (I),I=1,NTERMS)
        CLOSE(UNIT=7)
        GO TO 260
//
//      PRINT THE SOLUTION TO A MAZE
//
  240   WRITE(6,250) HEIGHT,WIDTH,DEPTH
  250   FORMAT('0',' YOUR MAZE HAS A HEIGHT OF',I5,/,'             AND A WIDTH OF',I5,/,'            WITH A DEPTH OF',I5,//,'  PRESS RETURN TO START')
        READ(5,40) NC,INPUT
//
//      PRINT MAZE
//
        CALL MAZSOL(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
//
//      CLEAR SCREEN AND WAIT 2 SECONDS
//
  260   CALL MAZOUT(CLEAR,2,1,24,1,0,0,0)
        CALL SYS$BINTIM( '0 ::02.00', SLEEP )
        CALL SYS$SCHDWK( , , SLEEP , )
        CALL SYS$HIBER
        STOP 'BYE FROM MAZE'
        END
 
        SUBROUTINE MAZGEN (  EXIT, LCOUNT, HEIGHT, WIDTH, DEPTH )
//
//      MAZGEN CREATES A MAZE IN EXIT
//
//      MAZE IS CREATED BY GOING FROM A START LOCATION IN A
//      RANDOM WALK
//      SQUARES MAY ONLY BE ENTERED ONCE BUT CAN HAVE MULTIPLE EXITS
//
//      MOVEMENT CONVENTION IS
//              1 - SOUTH OR DOWN
//              2 - EAST  OR RIGHT
//              4 - NORTH OR UP
//              8 - WEST  OR LEFT
//             16 - IN  A LEVEL
//             32 - OUT A LEVEL
//
        IMPLICIT INTEGER*4 (A-Z)
//
        INTEGER*2  EXIT(HEIGHT,WIDTH,DEPTH), LCOUNT(DEPTH)
//
        DIMENSION XDIR(4), YDIR(4), IN(4), OUT(4)
//
        REAL  SEED
//
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
//
        DATA XDIR / 0, 1, 0,-1 /
        DATA YDIR / 1, 0,-1, 0 /
        DATA IN   / 4, 8, 1, 2 /
        DATA OUT  / 1, 2, 4, 8 /
//
//      INITIALIZE AND PICK START AND END POSITIONS
//
        SEED = FOR$SECNDS(0)
        H = HEIGHT
        W = WIDTH
        D = DEPTH
        NENTER = 1
        LMAX = H * W
        NMAX = LMAX * D
        DO 10 L=1,D
        LCOUNT(L) = 0
        DO 10 J=1,W
        DO 10 I=1,H
   10   EXIT (I,J,L) = 0
//
        STARTH = IRAN(SEED,1,H)
        STARTW = IRAN(SEED,1,W)
        STARTD = 1
   20   ENDH   = IRAN(SEED,1,H)
        ENDW   = IRAN(SEED,1,W)
        ENDD   = D
        IF(STARTH.EQ.ENDH.AND.STARTW.EQ.ENDW.AND.STARTD.EQ.ENDD)GO TO 20
        SY = STARTH
        SX = STARTW
        SD = STARTD
        LCOUNT(SD) = 1
//
//      START FILLING IN MAZE
//
   30   ODIR = 0
        Y = SY
        X = SX
        L = SD
   40   DIR = IRAN(SEED,1,4)
//      DO NOT GO BACK ON YOURSELF
        IF( ODIR .EQ. OUT(DIR) ) GO TO 40
//
//      TEND TO MAKE LONGER LINES WITH NLOOPS
//
        NLOOPS = IRAN(SEED,1,DIR)
        NCOUNT=0
   50   NY = YDIR(DIR) + Y
        NX = XDIR(DIR) + X
        IF(NY.LT.1.OR.NY.GT.H) GO TO 40
        IF(NX.LT.1.OR.NX.GT.W) GO TO 40
        IF( EXIT(NY,NX,L) .EQ. 0 ) GO TO 80
//
//      CHECK FOR DEAD END
//
        DO 60 I=1,4
        TY = Y + YDIR(I)
        TX = X + XDIR(I)
        IF(TY.LT.1.OR.TY.GT.H) GO TO 60
        IF(TX.LT.1.OR.TX.GT.W) GO TO 60
//      NOT DEAD END TRY AGAIN
        IF( EXIT(TY,TX,L) .NE. 0 ) GO TO 60
        GO TO 40
   60   CONTINUE
//
//      DEAD END RETURN TO START UNLESS ALL DIRECTIONS ARE TAKEN
//
        IF( Y.EQ.SY .AND. X.EQ. SX ) GO TO 70
        GO TO 30
//
//      ALL STARTS FROM THIS STARTING POSITION ARE TAKEN
//      PICK A NEW STARTING POSITIONS UNTIL MAZE IS FULL
//
   70   SY = IRAN(SEED,1,H)
        SX = IRAN(SEED,1,W)
        IF( EXIT(SY,SX,L) .EQ. 0 ) GO TO 70
        IF( SY.EQ.STARTH.AND.SX.EQ.STARTW.AND.L.EQ.STARTD) GO TO 70
        IF( SY.EQ.ENDH  .AND.SX.EQ.ENDW  .AND.L.EQ.ENDD) GO TO 70
        IF( SY.EQ.Y     .AND.SX.EQ.X   ) GO TO 70
//
//      FILL IN A LAYER AT A TIME
//
        IF(LCOUNT(L).NE.LMAX) GO TO 30
        SD = SD + 1
        EXIT(SY,SX, L) = IOR(EXIT(SY,SX, L),16)
        EXIT(SY,SX,SD) = IOR(EXIT(SY,SX,SD),32)
        NENTER = NENTER + 1
        LCOUNT(SD) = 1
        GO TO 30
//
//      DIRECTION TO GO FOUND
//      SET POSITION AS HAVING BEEN ENTERED AND
//      SET EXIT ARRAY TO DIRECTIONS INVOLVED
//
   80   ODIR = IN(DIR)
        EXIT(Y,X,L)   = IOR(EXIT(Y,X,L),OUT(DIR))
        EXIT(NY,NX,L) = IOR(EXIT(NY,NX,L),IN(DIR))
        NENTER = NENTER + 1
        LCOUNT(L) = LCOUNT(L)+1
//      THE WAY OUT - ALL POINTS USED
        IF( NENTER .EQ. NMAX ) GO TO 90
        Y = NY
        X = NX
//
//      ONLY ALLOW THE END LOCATION TO BE ENTERED ONCE
//
        IF(Y.EQ.ENDH.AND.X.EQ.ENDW.AND.L.EQ.ENDD) GO TO 30
        NCOUNT=NCOUNT+1
        IF(NCOUNT.LT.NLOOPS) GO TO 50
        GO TO 40
//
//      OUT
//
   90   CONTINUE
        RETURN
        END
 
        SUBROUTINE MAZOUT( STRING, L, XOFF, Y, X, BOLD, REVERS, BLINK )
//*****
//  OUTPUTS -STRING- OF LENGTH -L- BYTES WITH BYTE NUMBER -XOFF-
//  OF STRING LOCATED AT CURSER LOCATION -X-, -Y-.
//
//  BOLD, REVERS, BLINK ARE THE MODES TO OUTPUT THIS STRING
//*****
        IMPLICIT INTEGER*2 (A-Z)
//
        LOGICAL ANY
//
        CHARACTER*300 CC
//
        BYTE STRING(L), LINEOUT(300), CHAR(10), ESCAPE
//
        DATA CHAR/ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' /
        DATA ESCAPE/ 27 /, C1,C2,C3 / 0,0,0/
//
        EQUIVALENCE(CC,LINEOUT(1))
//
        NL     = X - XOFF + 1
        NR     = NL + L - 1
        LENGTH = L
        ISTART = 1
        NX     = X
        NY     = Y
//
//  READJUST STRING LIMITS TO BE WITHIN SCREEN.  IF STRING IS
//  COMPLETELY OUT OF SCREEN, THEN RETURN DOING NOTHING.
//
        IF( NY.LT.1 .OR. NY.GT.24 ) RETURN
        IF( NR.LT.1 .OR. NL.GT.132 ) RETURN
//
//  STRING (ALL OR PART) LIES IN THE SCREEN AREA.
//
        IF( NL .GE. 1 ) GO TO 10
        ISTART = 2 - NL
        NL     = 1
        LENGTH = LENGTH - ISTART + 1
//
   10 IF( NR .LE. 132 ) GO TO 20
        LENGTH = LENGTH - (NR-132)
        NR = 132
//
//  OK AT THIS POINT WE ARE GOING TO OUTPUT STRING(ISTART) THRU
//  STRING(ISTART+LENGTH-1) STARTING AT SCREEN LOCAT SCREEN ION (NL,NY)
//
// 20  LINEOUT(1) = ' '
   20 LINEOUT(1) = ESCAPE
        LINEOUT(2) = '['
        IOUT = 2
        COORD = NY
        DO 40 I = 1,2
        ANY = .FALSE.
        DO 30 J = 1,3
        N = MOD( COORD/10**(3-J), 10 )
        IF( N.EQ.0 .AND. .NOT.ANY ) GO TO 30
        ANY = .TRUE.
        IOUT = IOUT + 1
        LINEOUT(IOUT) = CHAR(N+1)
   30 CONTINUE
        IOUT = IOUT + 1
        LINEOUT(IOUT) = ';'
        COORD = NL
   40 CONTINUE
        LINEOUT(IOUT) = 'H'
//
//  CHECK MODES AGAINST CURRENT MODES AND OUTPUT APPROPRIATE
//  MODE INDICATORS.
//
        IF( C1.NE.0 .AND.   BOLD.EQ.0 ) GO TO 80
        IF( C2.NE.0 .AND. REVERS.EQ.0 ) GO TO 80
        IF( C3.NE.0 .AND.  BLINK.EQ.0 ) GO TO 80
        IF( C1.EQ.BOLD .AND. C2.EQ.REVERS .AND. C3.EQ.BLINK )GO TO 120
//
//  OK SIMPLY ADD OUTPUT MODES
//
        LINEOUT(IOUT+1) = ESCAPE
        LINEOUT(IOUT+2) = '['
        IOUT = IOUT + 2
//
        IF( C1.EQ.BOLD   ) GO TO 50
        LINEOUT(IOUT+1) = '1'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
        C1   = BOLD
//
   50 IF( C2 .EQ. REVERS ) GO TO 60
        LINEOUT(IOUT+1) = '7'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
        C2 = REVERS
//
   60 IF( C3 .EQ. BLINK ) GO TO 70
        LINEOUT(IOUT+1) = '5'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
        C3 = BLINK
//
   70 LINEOUT(IOUT) = 'm'
        GO TO 120
//
//  SOME OR ALL OF CURRENT MODES ARE NOT DESIRED, THUS
//  MUST DO A NORMAL FOLLOWED BY A RESET OF MODES DESIRED.
//
   80 LINEOUT(IOUT+1) = ESCAPE
        LINEOUT(IOUT+2) = '['
        LINEOUT(IOUT+3) = '0'
        LINEOUT(IOUT+4) = ';'
        IOUT = IOUT + 4
//
        IF( BOLD .EQ. 0 ) GO TO 90
        LINEOUT(IOUT+1) = '1'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
//
   90 C1 = BOLD
        IF( REVERS .EQ. 0 ) GO TO 100
        LINEOUT(IOUT+1) = '7'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
//
  100 C2 = REVERS
        IF( BLINK .EQ. 0 ) GO TO 110
        LINEOUT(IOUT+1) = '5'
        LINEOUT(IOUT+2) = ';'
        IOUT = IOUT + 2
//
  110 C3 = BLINK
        LINEOUT(IOUT) = 'm'
//*****
//  OUTPUT THE STRING WITH ITS LEADER
//*****
  120 DO 130 I = 1,LENGTH
        LINEOUT(IOUT+I) = STRING(ISTART+I-1)
  130 CONTINUE
        IOUT = IOUT + LENGTH
//*****
//  BACK UP CURSER ONE LINE IF AT LINE 24
//*****
        IF( NY .NE. 24 ) GO TO 140
        LINEOUT(IOUT+1) = ESCAPE
        LINEOUT(IOUT+2) = 'M'
        IOUT = IOUT + 2
//*****
//  NOW READY TO OUTPUT THE STRING.
//*****
  140 RC = LIB$PUT_OUTPUT( CC(1:IOUT) )
        RETURN
        END
        FUNCTION IRAN( SEED, I, J )
//*****
//  RETURNS A RANDOM NUMBER IN THE RANGE OF I THRU J.
//  SEED IS UPDATED AND THUS A VARIABLE MUST BE SENT.
//*****
        REAL MTH$RANDOM
        FN = J - I + 1
        IRAN = I + IFIX( FN * MTH$RANDOM(SEED) )
        RETURN
        END
 
        SUBROUTINE MAZRUN(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
//
//      MAZRUN USES THE EXIT ARRAY TO CONTROL MAZE MOVEMENT
//                      MAT  ARRAY CONTAINS WHERE YOU HAVE BEEN
//
        IMPLICIT INTEGER*4 (A-Z)
//
        INTEGER*2 EXIT(HEIGHT,WIDTH,DEPTH)
        INTEGER*2 MAT (HEIGHT,WIDTH,DEPTH), ADD, MOVE(4,4)
//
        DIMENSION XDIR(4), YDIR(4), OUT(6), SLEEP(2)
//
        BYTE START(28),BELL,DEAD,LR132(10)
        BYTE SET(16)
        BYTE SCROL(8)
//
        CHARACTER*200 INPUT
        CHARACTER*10  NAME
        CHARACTER*6   PORT
//
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
//
        DATA XDIR / 0, 1, 0,-1 /
        DATA YDIR / 1, 0,-1, 0 /
        DATA OUT  / 1, 2, 4, 8, 16, 32 /
        DATA BELL / 7 /
//
//      ESCAPE SEQUENCES TO
//      ANSI MODE, ERASE SCREEN, ATTRIBUTES OFF, SCREEN NORMAL,
//      WRAP OFF, 80 COL., AND SPECIAL GRAPHICS
//
        DATA START/ 27,'<',27,'[','2','J',27,'[','0','m',27,'[','?','5','l',27,'[','?','7','l',  27,'[','?','3','l',27,'(','0'/
//
//      GRAPHICS CHARACTERS TO USE FOR DRAWING LINES
//
        DATA SET/' ', ' ', 'l', ' ', 'k', 'q', 'w', ' ','x', 'm', 't', 'j', 'u', 'v', 'n', 97 /
//
//      ESCAPE SEQUENCE TO SET 132 CHARACTER LINE MODE
//
        DATA LR132 / 27,'[','?','3','h' , 27,'[','?','5','h' /
//
//      SET SCROLLING REGION TO LAST TWO LINES (23-24)
//
        DATA SCROL / 27,'[','2','3',';','2','4','r' /
        DATA DEAD / 97 /
        DATA MOVE / 9, 5,-1, 3,10, 6, 3,-1,-1,12, 9,10,12,-1, 5, 6 /
//
//      SET UP FOR QIO FROM TERMINAL
//
        STATUS = SYS$TRNLOG( 'SYS$INPUT' ,, NAME ,,, )
        PORT = NAME( 5:10 )
        STATUS = SYS$ASSIGN( PORT, CHAN ,, )
        IF( STATUS.NE.1 ) RETURN
        READ = 49
        NOECHO = 64
        CVLOW = 256
//
//      CLEAR SCREEN AND SHOW START AND END OF MAZE
//
        CALL MAZOUT( START(1), 28, 1, 1,1, 0,0,0)
        IF(WIDTH.GT.80) CALL MAZOUT(LR132,10,1,1,1,0,0,0)
        CALL MAZOUT(SCROL,8,1,23,1,0,0,0)
        LOOP = 0
        SOVER = 0
//
//      BORDER
//
   10   CONTINUE
        Y = STARTH
        X = STARTW
        L = STARTD
   20   CONTINUE
        CALL MAZOUT(START(3),4,1,1,1,0,0,0)
        DO 40 I=1,HEIGHT
        CALL MAZOUT(' ',1,1, I,1     ,0,1,0)
        CALL MAZOUT(' ',1,1, I,WIDTH,0,1,0)
        IF(I.NE.1.AND.I.NE.HEIGHT) GO TO 40
        DO 30 J=2,WIDTH-1
        CALL MAZOUT(' ',1,1, I,J     ,0,1,0)
   30   CONTINUE
   40   CONTINUE
//
//      SHOW CURRENT STATUS OF MAZE SOLUTION
//
        DO 50 J=1,WIDTH
        DO 50 I=1,HEIGHT
        IF(IAND(EXIT(I,J,L),16).NE.0) CALL MAZOUT('O',1,1,I,J,1,1,1)
        IF(MAT(I,J,L).EQ.0) GO TO 50
        IF(MAT(I,J,L).GT.0.AND.MAT(I,J,L).LT.16)CALL MAZOUT(SET(MAT(I,J,L)),1,1,I,J,1,1,0)
        IF(MAT(I,J,L).LT.0) CALL MAZOUT('~',1,1,I,J,1,1,0)
        IF(MAT(I,J,L).EQ.64) CALL MAZOUT(SET(16),1,1,I,J,1,1,0)
        IF(MAT(I,J,L).GT.15.AND.MAT(I,J,L).LT.32)CALL MAZOUT('O',1,1,I,J,1,1,0)
        IF(MAT(I,J,L).GT.31.AND.MAT(I,J,L).LT.64)CALL MAZOUT('O',1,1,I,J,1,1,1)
   50   CONTINUE
        IF(LOOP.NE.0) CALL MAZOUT('O',1,1,Y,X,0,1,0)
        IF(L.EQ.ENDD) CALL MAZOUT( 'E',1,1,ENDH,ENDW,1,1,1)
        IF(L.EQ.STARTD) CALL MAZOUT( 'S',1,1,STARTH,STARTW,1,1,1)
        HOMEH = Y
        HOMEW = X
   60   DEADE = 0
        ODIR = 0
//
//      READ INPUT AND MOVE AS REQUESTED
//
        ESC = 0
        OPT =  READ + NOECHO + CVLOW
   70   CALL MAZOUT(' ',1,1,24,1,0,0,0)
//
        STATUS = SYS$QIOW( , %VAL(CHAN), %VAL(OPT),,,,%VAL(%LOC(INPUT)), %VAL(1),,,, )
        IF( STATUS .NE. 1 ) RETURN
//
   80   FORMAT(Q,A)
        IF( ESC .EQ. 1 ) GO TO 140
        IF(ICHAR(INPUT(1:1)) .EQ. 27 ) GO TO 130
        IF(INPUT(1:1) .EQ.'Q') RETURN
        IF(INPUT(1:1) .EQ.'B') GO TO 90
        IF(INPUT(1:1) .EQ.'M') GO TO 100
        IF(INPUT(1:1) .EQ.'C' ) GO TO 110
        IF(INPUT(1:1).NE.'H') GO TO 160
        IF(Y.EQ.HOMEH.AND.X.EQ.HOMEW) GO TO 60
        SOVER=1
        ADD = -1
        GO TO 220
   90   NOBELL = 0
        GO TO 70
  100   NOBELL = 1
        GO TO 70
  110   WRITE(6,120) L
  120   FORMAT( ' CURRENT LEVEL IS ',I2)
        GO TO 70
  130   ESC = 1
        GO TO 70
  140   IF(INPUT(1:1) .EQ. '[' ) GO TO 70
        GO TO 170
  150   SOVER = 0
        Y = HOMEH
        X = HOMEW
        GO TO 60
//
//      FIND DIRECTION TO GO
//
  160   DIR = 0
        IF(ICHAR(INPUT(1:1)).EQ.27) GO TO 170
        IF(INPUT(1:1).EQ.'S'.OR.INPUT(1:1).EQ.'D') DIR=1
        IF(INPUT(1:1).EQ.'E'.OR.INPUT(1:1).EQ.'R') DIR=2
        IF(INPUT(1:1).EQ.'N'.OR.INPUT(1:1).EQ.'U') DIR=3
        IF(INPUT(1:1).EQ.'W'.OR.INPUT(1:1).EQ.'L') DIR=4
        IF(INPUT(1:1).EQ.'2') DIR=1
        IF(INPUT(1:1).EQ.'6') DIR=2
        IF(INPUT(1:1).EQ.'8') DIR=3
        IF(INPUT(1:1).EQ.'4') DIR=4
        IF(INPUT(1:1).EQ.'I'.OR.INPUT(1:1).EQ.'9') DIR=5
        IF(INPUT(1:1).EQ.'O'.OR.INPUT(1:1).EQ.'7') DIR=6
        GO TO 180
//
//      CHECK ARROW KEYS ( DID NOT HAVE TIME TO MAKE THIS WORK )
//
  170   IF(INPUT(1:1).EQ.'A') DIR=3
        IF(INPUT(1:1).EQ.'B') DIR=1
        IF(INPUT(1:1).EQ.'C') DIR=2
        IF(INPUT(1:1).EQ.'D') DIR=4
        ESC = 0
  180   IF(DIR.NE.0) GO TO 200
//
//      COMMAND NOT RECOGNIZED
//
        WRITE(6,190)
  190   FORMAT(' TRY AGAIN ')
        GO TO 70
//
//      SEE IF DIRECTION IS LEGAL
//
  200   IF( IAND(EXIT(Y,X,L),OUT(DIR)) .NE. 0 ) GO TO 210
        IF(NOBELL .NE. 0 ) GO TO 70
        CALL MAZOUT( BELL ,1,1, 24,1, 0,0,0 )
        GO TO 70
//
//      MOVE KEEP MOVEMENT ARRAY MAT UP TO DATE
//
  210   IF(Y.EQ.STARTH.AND.X.EQ.STARTW.AND.L.EQ.STARTD) GO TO 230
        IF(DEADE.EQ.1) GO TO 230
        ADD = OUT(DIR)
        IF(ODIR.NE.0.AND.DIR.LT.5) ADD = MOVE(ODIR,DIR)
        IF(ODIR.EQ.0) ADD = 0
  220   IF(MAT(Y,X,L).EQ.-1) MAT(Y,X,L) = 0
        IF(ADD.EQ.-1 .AND. MAT(Y,X,L).EQ.0 ) MAT(Y,X,L) = ADD
        IF(ADD.NE.-1) MAT(Y,X,L) = IOR(MAT(Y,X,L),ADD)
        IF(MAT(Y,X,L).GT.0.AND.MAT(Y,X,L).LT.16)CALL MAZOUT(SET(MAT(Y,X,L)),1,1,Y,X,1,1,0)
        IF(MAT(Y,X,L).LT.0) CALL MAZOUT( '~' ,1,1,Y,X,1,1,0)
  230   IF(SOVER.EQ.1) GO TO 150
        IF( DIR.LT.5 ) GO TO 240
//
//      CHANGE LEVELS
//
        IF( DIR.EQ.5 ) L = L+1
        IF( DIR.EQ.6 ) L = L-1
        MAT(Y,X,L) = OUT(DIR)
        LOOP = LOOP + 1
        GO TO 20
  240   Y = Y + YDIR(DIR)
        X = X + XDIR(DIR)
        IF(Y.EQ.STARTH.AND.X.EQ.STARTW.AND.L.EQ.STARTD) GO TO 70
        IF(MAT(Y,X,L).LT.16) CALL MAZOUT('{',1,1,Y,X,0,1,1)
        DEADE = 0
        ODIR = DIR
        IF(Y.EQ.ENDH.AND.X.EQ.ENDW.AND.L.EQ.ENDD) GO TO 270
//
//      CHECK FOR DEAD END
//
        DO 250 I=1,6
        IF( EXIT(Y,X,L) .EQ. OUT(I) ) GO TO 260
  250   CONTINUE
        GO TO 70
//
//      DEAD END
//
  260   CALL MAZOUT(DEAD,1,1,Y,X,0,0,0)
        MAT(Y,X,L) = 64
        DEADE = 1
        GO TO 70
  270   CONTINUE
//
//      SUCCESS - END FOUND
//
        DO 290 I=1,6
        J=MOD(I,2)
        CALL MAZOUT('E',1,1,ENDH,ENDW,1,J,1)
        CALL MAZOUT(' ',1,1,24,1,0,J,1)
        WRITE(6,280)
  280   FORMAT(' SUCCESS SUCCESS SUCCESS' )
        CALL SYS$BINTIM( '0 ::00.50', SLEEP )
        CALL SYS$SCHDWK( , , SLEEP , )
        CALL SYS$HIBER
  290   CONTINUE
        RETURN
        END
 
        SUBROUTINE MAZSOL(EXIT,MAT,HEIGHT,WIDTH,DEPTH)
//
//      MAZSOL SHOWS ALL POSSIABLE PATHS IN MAZE
//
        IMPLICIT INTEGER*4 (A-Z)
//
        INTEGER*2 EXIT(HEIGHT,WIDTH,DEPTH)
        INTEGER*2 MAT (HEIGHT,WIDTH,DEPTH), ADD, MOVE(4,4)
        DIMENSION XDIR(4), YDIR(4), OUT(4), SLEEP(2)
//
        BYTE START(28),BELL,DEAD,LR132(10)
        BYTE SET(16)
        BYTE SCROL(8)
//
        CHARACTER*200 INPUT
//
        COMMON /MAZECM/ STARTH,STARTW,STARTD,ENDH,ENDW,ENDD,NOBELL
//
        DATA XDIR / 0, 1, 0,-1 /
        DATA YDIR / 1, 0,-1, 0 /
        DATA OUT  / 1, 2, 4, 8 /
        DATA BELL / 7 /
        DATA START/ 27,'<',27,'[','2','J',27,'[','0','m',27,'[','?','5','l',27,'[','?','7','l',  27,'[','?','3','l',27,'(','0'/
        DATA SET/' ', ' ', 'l', ' ', 'k', 'q', 'w', ' ','x', 'm', 't', 'j', 'u', 'v', 'n', 97 /
        DATA LR132 / 27,'[','?','3','h' , 27,'[','?','5','h' /
        DATA SCROL / 27,'[','2','3',';','2','4','r' /
        DATA DEAD / 97 /
        DATA MOVE / 0, 3, 9, 5, 3, 0,10, 6, 9,10, 0,12, 5, 6,12, 0 /
//
//      CLEAR SCREEN AND SHOW START AND END OF MAZE
//
        CALL MAZOUT( START(1), 28, 1, 1,1, 0,0,0)
        IF(WIDTH.GT.80) CALL MAZOUT(LR132,10,1,1,1,0,0,0)
        CALL MAZOUT(SCROL,8,1,23,1,0,0,0)
//
//      BORDER
//
        DO 70 L = 1,DEPTH
        IF(L.EQ.ENDD) CALL MAZOUT( 'E',1,1,ENDH,ENDW,1,1,1)
        IF(L.EQ.STARTD) CALL MAZOUT( 'S',1,1,STARTH,STARTW,1,1,1)
//
//      LOOP OVER MAZE
//
        DO 40 X=1,WIDTH
        DO 40 Y=1,HEIGHT
        MAT(Y,X,L) = 0
        IF(Y.EQ.STARTH.AND.X.EQ.STARTW.AND.L.EQ.STARTD) GO TO 40
        IF(Y.EQ.ENDH  .AND.X.EQ.ENDW  .AND.L.EQ.ENDD) GO TO 40
//
//      CHECK FOR DEAD END
//
        DO 20 ODIR=1,4
        IF( EXIT(Y,X,L) .EQ. OUT(ODIR) ) GO TO 30
        IF( IAND(EXIT(Y,X,L),OUT(ODIR)) .EQ. 0 ) GO TO 20
        DO 10 DIR=1,4
        IF(DIR.EQ.ODIR) GO TO 10
        IF( IAND(EXIT(Y,X,L),OUT(DIR)) .EQ. 0 ) GO TO 10
        ADD = MOVE(ODIR,DIR)
        MAT(Y,X,L) = IOR(MAT(Y,X,L),ADD)
   10   CONTINUE
   20   CONTINUE
        IF(EXIT(Y,X,L).LT.16) CALL MAZOUT(SET(MAT(Y,X,L)),1,1,Y,X,1,1,0)
        IF(IAND(EXIT(Y,X,L),16).NE.0) CALL MAZOUT('O',1,1,Y,X,1,1,1)
        IF(IAND(EXIT(Y,X,L),32).NE.0) CALL MAZOUT('O',1,1,Y,X,1,1,0)
        GO TO 40
//
//      DEAD END
//
   30   CALL MAZOUT(DEAD,1,1,Y,X,0,0,0)
   40   CONTINUE
//
//      SUCCESS - END FOUND
//
        CALL MAZOUT(' ',1,1,24,1,0,0,0)
        WRITE(6,50)
   50   FORMAT('  PRESS RETURN TO CONTINUE OR FINISH')
        READ(5,60) NC,INPUT
   60   FORMAT(Q,A)
   70   CONTINUE
        RETURN
        END