SUBROUTINE NELLIE
      IMPLICIT INTEGER(A - Z)
C
C	THIS SUBROUTINE CONTROLS THE MOTION OF NELLIE.
C	NELLIE MOVES AT 83% OF TOP SPEED, AND MAKES DIRECTION-CHANGING
C	DECISIONS AT DECISION POINTS APPROXIMATELY HALF THE TIME.
C
C
C	VT100 DISPLAY CONTROL PARAMETER DEFINITIONS
C
CCURSOR POSITION REPORT
CCURSOR UP
CCURSOR DOWN
CCURSOR FORWARD
CCURSOR BACK
CDOUBLE WIDTH LINE
      PARAMETER CUP = 1, CUU = 2, CUD = 3, CUF = 4, CUB = 5, DECDWL = 6,
     * DECDHL = 7, DECRC = 8, DECSC = 9, DECSWL = 10, ED = 11, EL = 12, 
     *SGR = 13, NEL = 14, SCS = 15, SM = 16, RM = 17, ANSI = 18, CPP=19
C MAZE DIMENSIONS
      PARAMETER RMAR = 24, CMAR = 53
C BIT SETTINGS FOR DIRECTIONALS AND MSTATE TABLE
      PARAMETER HALT = 0, UP = 1, DOWN = 2, LEFT = 4, RIGHT = 8
	PARAMETER DOT=16, EGZ=32, TUNNEL=64, DECISN="200
	PARAMETER SHFIN="17, SHFOUT="16, SPACE="40
C DISPLAYABLE CHARACTERS
	PARAMETER PMAN="52, EGZCHR="146, DOTCHR="176, TUNCHR="137
C BOARD STATE
      PARAMETER GOOD = 1, BAD = 2, BLINK = 3, EATEN = 4
C QIO FUNCTION CODES
	PARAMETER IOWVB="11000
C
      INTEGER*4SCORE, TIMER, STATIM, LTIM, CTIM, FTIM, NTIM, FRUON, FRUO
     *FF
      INTEGER*2PRL(6), EATSCO(4), FRUSCO(6), FRUDSR(20), FRUDSC(20)
      BYTE LMAN(3), CMAN(3), FMAN(3), NMAN(3), EATCHR(4), FRUCHR(6)
      BYTE MSTATE(CMAR, RMAR), MOVE(24, 9), FRUTBL(20)
C COMMONS
      COMMON/MSTCOM/MSTATE
      COMMON/PACCOM/FDIR, NDIR, LDIR, CDIR, CYCLE, MOVE, SCORE, DOTCNT, 
     *COL, ROW, LCOL, LROW, CCOL, CROW, FCOL, FROW, NCOL, NROW, CYCTIM, 
     *TIMER, BOARD, STATE, STATIM, LTIM, CTIM, FTIM, NTIM, LPRISN, CPRIS
     *N, FPRISN, NPRISN, LPRISR, LPRISC, CPRISR, CPRISC, FPRISR, FPRISC,
     * NPRISR, NPRISC, RDOOR, CDOOR, PRITIM, GOODTM, BLNKTM, EATCNT, EAT
     *CHR, EATSCO, EXTRA, LMAN, CMAN, FMAN, NMAN, PACCNT, INIROW, INICOL
     *, GAMOVR, FRUIT, FRUTIM, FRULTH, FRUON, FRUOFF, FRUSCO, FRUCHR, FR
     *UCOL, FRUROW, FRUCNT, FRUDSR, FRUDSC, PRL, FRUTBL, PACDSC, PACDSR,
     * PACDSD, FRUBRD
C
C	TEST IF WE ARE IN PRISON
C
      OLDDIR = NDIR
      IF (.NOT.(NPRISN .EQ. 1)) GOTO 2000
CIF IN PRISON...
        IF (.NOT.(STATE .NE. BAD)) GOTO 2020
CDONT ESCAPE IF PACMAN IS
CEATING MONSTERS
          RETURN
2020    CONTINUE
        IF (.NOT.(NTIM+PRITIM .LE. TIMER)) GOTO 2040
CIF TIME TO GET OUT,
CERASE US FROM IN PRISON
          CALL UVT100(CPP, NPRISR, NPRISC, SPACE)
          NROW = RDOOR
          NCOL = CDOOR
CMOVE HIM TO PRISON DOOR
          CALL UVT100(CPP, NROW, NCOL, NMAN(STATE))
CNO LONGER IN PRISON
          NPRISN = 0
CNO MOTION YET
          NDIR = HALT
CNOT YET TIME TO GET OUT
          GOTO 2050
2040    CONTINUE
          RETURN
2050    CONTINUE
C
C	IF PACMAN IS IN AN EATING MOOD (STATE IS 'GOOD' OR 'BLINK'),
C	ALL MONSTERS MOVE AT 67% OF TOP SPEED. TEST FOR THIS CONDITION.
C
2000  CONTINUE
      IF (.NOT.(STATE .NE. BAD.AND.MOVE(CYCLE, 9) .EQ. 0)) GOTO 2060
        NDIR = OLDDIR
        RETURN
C
C	IF THIS IS A TUNNEL LOCATION, TEST IF MOTION ALLOWED THIS CYCLE
C
2060  CONTINUE
      IF (.NOT.(TSTBIT(MSTATE(NCOL, NROW), TUNNEL) .EQ. 1)) GOTO 2080
        IF (.NOT.(MOVE(CYCLE, 3) .EQ. 0)) GOTO 2100
          NDIR = OLDDIR
          RETURN
2100    CONTINUE
C
C	ELSE IF THIS IS A DECISION BIT, CALL DECIDE TO DETERMINE DIRECTION
C	TO GO. (ONLY DO THIS IF ON SAME ROW OR COLUMN, OR, FOR FIRST TWO
C	BOARDS, 50% OF THE TIME, OR FOR THE NEXT TWO BOARDS, 75% OF THE
C	TIME, OR FOR LATER BOARDS, 92% OF THE TIME).
C
        GOTO 2090
2080  CONTINUE
      IF (.NOT.(TSTBIT(MSTATE(NCOL, NROW), DECISN) .EQ. 1)) GOTO 2120
        IF (.NOT.(NCOL .EQ. COL.OR.NROW .EQ. ROW)) GOTO 2140
          CALL DECIDE(NCOL, NROW, NDIR)
          GOTO 2150
2140    CONTINUE
        IF (.NOT.(BOARD .LT. 3.AND.MOVE(CYCLE, 3) .EQ. 0)) GOTO 2160
          CALL DECIDE(NCOL, NROW, NDIR)
          GOTO 2150
2160    CONTINUE
        IF (.NOT.(BOARD .GT. 2.AND.BOARD .LT. 5.AND.MOVE(CYCLE, 6) .EQ. 
     *1)) GOTO 2180
          CALL DECIDE(NCOL, NROW, NDIR)
          GOTO 2150
2180    CONTINUE
        IF (.NOT.(BOARD .GT. 4.AND.MOVE(CYCLE, 5) .EQ. 1)) GOTO 2200
          CALL DECIDE(NCOL, NROW, NDIR)
2200    CONTINUE
2150    CONTINUE
C
C	IF WE HAVE RUN INTO A WALL, FIND A NEW DIRECTION
C
2120  CONTINUE
2090  CONTINUE
      IF (.NOT.(TSTBIT(MSTATE(NCOL, NROW), NDIR) .EQ. 0)) GOTO 2220
        CALL WALL(NCOL, NROW, NDIR)
C
C	IF MOTION IS PROHIBITED THIS CYCLE, RESET OLD DIRECTION AND RETURN
C
2220  CONTINUE
      IF (.NOT.(MOVE(CYCLE, NDIR) .EQ. 0.OR.MOVE(CYCLE, 7) .EQ. 0)) GOTO
     * 2240
        NDIR = OLDDIR
        RETURN
C
C	ALL READY TO MOVE
C
2240  CONTINUE
CCURSOR TO CURRENT LOCATION

      IF (.NOT.(TSTBIT(MSTATE(NCOL, NROW), DOT) .EQ. 1)) GOTO 2260
        CALL UVT100(CPP, NROW, NCOL, DOTCHR)
CREWRITE DOT
        GOTO 2270
2260  CONTINUE
      IF (.NOT.(TSTBIT(MSTATE(NCOL, NROW), EGZ) .EQ. 1)) GOTO 2280
        CALL UVT100(CPP, NROW, NCOL, EGZCHR)
CREWRITE ENERGIZER
        GOTO 2270
2280  CONTINUE
      IF (.NOT.(FRUIT .EQ. 1.AND.NCOL .EQ. FRUCOL.AND.NROW .EQ. FRUROW))
     * GOTO 2300
        CALL UVT100(CPP, NROW, NCOL, FRUCHR(BOARD))
CREWRITE FRUIT
        GOTO 2270
2300  CONTINUE
        CALL UVT100(CPP, NROW, NCOL, SPACE)
CREWRITE SPACE
2270  CONTINUE
      IF (.NOT.(NDIR .EQ. LEFT)) GOTO 2320
        NCOL = NCOL - 1
        GOTO 2330
2320  CONTINUE
      IF (.NOT.(NDIR .EQ. UP)) GOTO 2340
        NROW = NROW - 1
        GOTO 2330
2340  CONTINUE
      IF (.NOT.(NDIR .EQ. RIGHT)) GOTO 2360
        NCOL = NCOL + 1
        GOTO 2330
2360  CONTINUE
      IF (.NOT.(NDIR .EQ. DOWN)) GOTO 2380
        NROW = NROW + 1
2380  CONTINUE
2330  CONTINUE
      IF (.NOT.(NCOL .GT. CMAR)) GOTO 2400
        NCOL = 1
        GOTO 2410
2400  CONTINUE
      IF (.NOT.(NCOL .LT. 1)) GOTO 2420
        NCOL = CMAR
2420  CONTINUE
2410  CONTINUE
      IF (.NOT.(NROW .GT. RMAR)) GOTO 2440
        NROW = 1
        GOTO 2450
2440  CONTINUE
      IF (.NOT.(NROW .LT. 1)) GOTO 2460
        NROW = RMAR
2460  CONTINUE
2450  CONTINUE
      CALL UVT100(CPP, NROW, NCOL, NMAN(STATE))
CTEST FOR COLLISION
      CALL COLIDE
      RETURN
      END