anchor.diff:            record = record + 1
             read( 10, rec = record, iostat = ierr ) (img(i), i = 1,bytes )
             if ( ierr .ne. 0 ) then
  -             exit
  +              read_img = .false.
  +              return
             endif
   
             do i = 1,bytes
  
positive.code:               read( 10, rec = record ) (img(b), b = 1,bytes )
                first  = 1
            else
                exit
            endif
        enddo
  
  
negative.code: 
            if (ierr .ne. 0) then
                read_img = .false.
                return
            endif
  
            if (ver(1:1) .ne. '#' ) then
                read_img = .false.
                return
            endif
        enddo
  
  