SUBROUTINE JR4FM (XL,YL,SIDEX,SIDEY,NITER,CR,CI,COL,MCPAX,MCPAY)
C
C     COPYRIGHT (C) 1985-1992 BY ART MATRIX.  ALL RIGHTS RESERVED.
C
      IMPLICIT REAL*8 (A-H,O-Z)
C
      INTEGER*2   COL(0:MCPAX,0:MCPAY)
      INTEGER*4   PENP(0:3),PENN(0:3)
C
      COMPLEX*16  Z,A,AZ,B,C,CMCC,D,ALPHA
C
         DATA  PENP/1, 2, 3, 4/
         DATA  PENN/9,10,11,12/
C
C***********************************************************************
C***********************************************************************
C
      CALL DRVID ('FM      ',102,2,1,13)
C
C***********************************************************************
C***********************************************************************
C
      C       =   DCMPLX(CR,CI)
C
      CMCC    =   C - C*C
C
      A       =   (2 - C)/CMCC
      B       =  -(CMCC + 1)/CMCC
C
      ALPHA   =   1/(  C*C * (B + B + B*B/A) * (2*A*C + B) )
      ESC   =   4/ABS(ALPHA)
      ESC   =   ESC *ESC
      EPS  =   .000001/ESC
C
C***********************************************************************
C***********************************************************************
C
      DO 2000 IY = 0,MCPAY
C
         Y = YL + (IY*SIDEY)/MCPAY
C
         CALL SHOWIY (10,IY,Y)
C
         DO 1000 IX = 0,MCPAX
C
            X = XL + (IX*SIDEX)/MCPAX
C
C***********************************************************************
C***********************************************************************
C
      DER  =   1.0
      Z    =   DCMPLX(X,Y)
      Z    =   1/(A*Z*Z + B*Z + 1)
      Z    =   1/(A*Z*Z + B*Z + 1)
      Z    =   1/(A*Z*Z + B*Z + 1)
      Z    =   1/(A*Z*Z + B*Z + 1)
C
      DO 400 I = 5,NITER
C
         AZ   =  A*Z
         Z    =  1/(AZ*Z + B*Z + 1)
C
         IF (DREAL(Z)*DREAL(Z) + IMAG(Z)*IMAG(Z) .GT. ESC ) GOTO 200
C
         D    =   (2*AZ + B)*Z*Z
         DER  =   DER*(DREAL(D)*DREAL(D) + IMAG(D)*IMAG(D))
         IF (DER .LT. EPS) GOTO 300
C
400   CONTINUE
C
      COL(IX,IY) = 7
      GOTO 1000
C
200   IF (IMAG(ALPHA*Z) .LE. 0) THEN
         COL(IX,IY) = PENP(MOD(I,4)) + 13*I
         GOTO 1000
      ELSE
         COL(IX,IY) = PENN(MOD(I,4)) + 13*I
         GOTO 1000
      ENDIF
C
300   COL(IX,IY) = 13*I
      GOTO 1000
C
C***********************************************************************
C***********************************************************************
C
1000     CONTINUE

2000  CONTINUE
C
      RETURN
      END