anchor.diff:                 NZZ = NZ
                  EXIT
               ENDIF
  -        END DO       
  -        
  +        END DO
  +
           ! Increment atom count in appropriate grid square and the total
           INC(NXX,NYY,NZZ) = INC(NXX,NYY,NZZ) + 1
  -        ISUM = ISUM + 1        
  -        
  +        ISUM = ISUM + 1
  +
       END IF
   
   END DO
  
positive.code: 
      READ(PDBFIL, ATMFMT, IOSTAT=IERR) ATOM, AANAM, RESNUM, X
      IF (IERR .LT. 0) EXIT
      
      IF (ATOM .EQ. "ATOM") THEN
          NATOMM = NATOMM + 1
          XMA = MAX(XMA, X(1))
  
negative.code:     READ(5,*) XMI, YMI, ZMI
  ENDIF
  
  RADIS = BOX/2.0
  
  ! Two passes are made through the protein file.
  ! 1. Gets statistics including volume and number of residues
  