program readplds

      parameter (width=720, height = 340)

      character*1 lrec(width)

      integer col, row, rlen, snow(width,height), x, y

C     record length is specified in words not bytes
      rlen = width / 4

C     open file
      open(unit=1, file='mthly_snow_198012.plds.new', 
     1     form='unformatted', access='direct', recl=rlen)

C     read header and display
      read(1) lrec
      write(*,*) lrec

      do row = 1, height
        read(1) lrec

        do col = 1, width
          value = ichar(lrec(col))
          if (value .lt. 0) value = value + 256
          snow(col, row) = value
        end do

      end do

      close(1)

C     query grid
 100  continue
      print *, 'enter x y from rdpix'
      read *, x, y
      col = x + 1
      row = height - y
      print '(a,i4,a,i4,a,i4)', 
     1     'col=', col, ', row=', row, ', value=', snow(col,row)
      goto 100

      end