SUBROUTINE RELEAS
C
C	THIS SUBROUTINE CONTROLS THE RELEASE OF NEW CENTIPEDES,
C	FLEAS, SPIDERS, AND SCORPIONS ONTO THE SCREEN.
C
      IMPLICIT INTEGER(A - Z)
      PARAMETER MAXCNT = 24
C SCREEN BOUNDARIES
      PARAMETER LMAR = 2, RMAR = 30, TMAR = 2, BMAR = 23, GMAR = 18
C DIRECTIONALS
      PARAMETER HALT = 0, UP = 1, DOWN = 2, LEFT = 4, RIGHT = 8
      PARAMETER UPL = 10, UPR = 9, DOWNL = 12, DOWNR = 11
C DISPLAYABLE CHARACTERS
	PARAMETER GUNCHR="166, CBODY="140, MSHCHR="146, BULCHR="170
	PARAMETER SPICHR="173, FLECHR="175, SCOCHR="142, PSNCHR="052
	PARAMETER CLHEAD="074, CRHEAD="076, CDHEAD="126
	PARAMETER SHFIN="17, SHFOUT="16, SPACE="40
C QIO FUNCTION CODES
	PARAMETER IOATA="1410, IOWVB="11000, SFSMC="2440
C
      INTEGER*4SCORE, FRESCO, TIMER, SEED, FLETIM, SPITIM, SCOTIM, CNTTI
     *M
      DIMENSION PRL(6), CX(MAXCNT, 12), CY(MAXCNT, 12)
      DIMENSION CLEN(MAXCNT), CDIR(MAXCNT), CRISE(MAXCNT), CBOT(MAXCNT)
      BYTE CNTBRD(BMAR, RMAR), MSHBRD(BMAR, RMAR), PSNBRD(BMAR, RMAR)
      COMMON/DIRCOM/DIRCOD, FIRCOD
      COMMON/CNTCOM/PRL, SCORE, TIMER, SEED, CX, CY, CLEN, CDIR, CRISE, 
     *CBOT, GUNX, GUNY, FRESCO, CNTBRD, MSHBRD, PSNBRD, BULACT, BULX, BU
     *LY, FLETIM, FLEACT, FLEX, FLEY, SPITIM, SPIACT, SPIX, SPIY, SPILR,
     * SCOTIM, SCOACT, SCOX, SCOY, SCODIR, GUNCNT, CNTTIM, BOARD, CNTWAV
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
      REAL X, RAN
      DATA ZONCNT/30/
C
C	CENTIPEDES (THE FIRST CENTIPEDE OF A BOARD IS RELEASED BY SUBROUTINE
C	'START'.  ALL CENTIPEDES AFTER THE FIRST ARE ONE SEGMENT LONG)
C
      IF (.NOT.(CNTTIM .GT. 0.AND.CNTTIM .LE. TIMER)) GOTO 2000
        X = RAN(SEED)
        RAND = X*2
        DO 2020 I = 1, MAXCNT
CSEARCH CENTIPEDE TABLE FOR EMPTY SLOT
          IF (.NOT.(CLEN(I) .NE. 0)) GOTO 2040
CTHIS SLOT IN USE
            GOTO 2020
2040      CONTINUE
          IF (.NOT.(CNTWAV .GT. 0)) GOTO 2060
CCENTIPEDE STARTS AT TOP OF SCREEN
            CX(I, 1) = TMAR
            GOTO 2070
2060      CONTINUE
CCENTIPEDE STARTS AT TOP OF PLAYERZONE
            CX(I, 1) = GMAR
2070      CONTINUE
CCENTIPEDE IS ONE SEGMENT LONG
          CLEN(I) = 1
CAND DESCENDING
          CRISE(I) = 1
          IF (.NOT.(RAND .EQ. 0)) GOTO 2080
CSTART AT RIGHT OR LEFT EDGE (RANDOM)
            CY(I, 1) = LMAR
            CDIR(I) = RIGHT
            GOTO 2090
2080      CONTINUE
            CY(I, 1) = RMAR
            CDIR(I) = LEFT
2090      CONTINUE
          IF (.NOT.(CDIR(I) .EQ. LEFT)) GOTO 2100
CDISPLAY IT
            CALL UVT100(CPP, CX(I, 1), CY(I, 1), CLHEAD)
            GOTO 2110
2100      CONTINUE
            CALL UVT100(CPP, CX(I, 1), CY(I, 1), CRHEAD)
2110      CONTINUE
          GOTO 2030
2020    CONTINUE
2030    CONTINUE
        IF (.NOT.(CNTWAV .GT. 0)) GOTO 2120
CRELEASE ANOTHER CENTIPEDE
          IF (.NOT.(SCORE .GT. 40000)) GOTO 2140
CFROM TOP OF SCREEN.
CZONCNT IS USED TO TIME RELEASES
            ZONCNT = 10
            GOTO 2150
2140      CONTINUE
          IF (.NOT.(SCORE .GT. 30000)) GOTO 2160
CBASED ON THE PLAYER'S SCORE.
CWHEN ALL CENTIPEDES OF THIS BOARD
            ZONCNT = 15
            GOTO 2150
2160      CONTINUE
          IF (.NOT.(SCORE .GT. 20000)) GOTO 2180
CHAVE BEEN RELEASED AND REACHED BOTTOM
COF PLAYER'S ZONE, NEW ONES ARE
            ZONCNT = 20
            GOTO 2150
2180      CONTINUE
          IF (.NOT.(SCORE .GT. 10000)) GOTO 2200
CRELEASED FROM THE TOP OF THE ZONE.
            ZONCNT = 25
            GOTO 2150
2200      CONTINUE
            ZONCNT = 30
2150      CONTINUE
CCNTWAV IS THE NUMBER OF CENTIPEDES
          CNTWAV = CNTWAV - 1
          IF (.NOT.(CNTWAV .GT. 0)) GOTO 2220
CLEFT TO BE RELEASED FROM SCREEN TOP.
            CNTTIM = TIMER + (ZONCNT - 5)
            GOTO 2230
2220      CONTINUE
CLAST CENTIPEDE FROM TOP OF SCREEN
            CNTTIM = 0
2230      CONTINUE
          GOTO 2130
2120    CONTINUE
CALL CENTIPEDES HAVE BEEN RELEASED.
          IF (.NOT.(ZONCNT .GT. 0)) GOTO 2240
CCALCULATE RELEASE TIME FOR NEXT
CCENTIPEDE IN PLAYER'S ZONE.
            ZONCNT = ZONCNT - 1
2240      CONTINUE
          CNTTIM = TIMER + ((ZONCNT/5 + 1)*10)
2130    CONTINUE
C
C	FLEA
C
2000  CONTINUE
      IF (.NOT.(FLETIM .GT. 0.AND.FLEACT .EQ. 0.AND.FLETIM .LE. TIMER)) 
     *GOTO 2260
        X = RAN(SEED)
CSTART AT TOP OF SCREEN
        FLEX = TMAR
CRANDOM COLUMN
        FLEY = (X*(RMAR - LMAR + 1)) + LMAR
        FLEACT = 1
CDISPLAY HIM
        CALL UVT100(CPP, FLEX, FLEY, FLECHR)
C
C	SPIDER
C
2260  CONTINUE
      IF (.NOT.(SPITIM .GT. 0.AND.SPIACT .EQ. 0.AND.SPITIM .LE. TIMER)) 
     *GOTO 2280
        X = RAN(SEED)
        RAND = X*2
        SPIX = GMAR
        IF (.NOT.(RAND .EQ. 0)) GOTO 2300
CMOVES RIGHT TO LEFT OR LEFT TO RIGHT
C(RANDOM)
          SPIY = LMAR
          SPILR = RIGHT
          GOTO 2310
2300    CONTINUE
          SPIY = RMAR
          SPILR = LEFT
2310    CONTINUE
        SPIACT = 1
CDISPLAY HIM
        CALL UVT100(CPP, SPIX, SPIY, SPICHR)
C
C	SCORPION
C
2280  CONTINUE
      IF (.NOT.(SCOTIM .GT. 0.AND.SCOACT .EQ. 0.AND.SCOTIM .LE. TIMER)) 
     *GOTO 2320
        X = RAN(SEED)
CSCORPION APPEARS ON TOP TEN ROWS
        SCOX = (X*9) + TMAR + 1
C(EXCEPT NOT ON VERY TOP ROW)
        X = RAN(SEED)
        RAND = X*2
        IF (.NOT.(RAND .EQ. 0)) GOTO 2340
CMOVES RIGHT TO LEFT OR LEFT TO RIGHT
C(RANDOM)
          SCOY = LMAR
          SCODIR = RIGHT
          GOTO 2350
2340    CONTINUE
          SCOY = RMAR
          SCODIR = LEFT
2350    CONTINUE
CDISPLAY HIM
        CALL UVT100(CPP, SCOX, SCOY, SCOCHR)
        SCOACT = 1
2320  CONTINUE
      RETURN
      END