7   'nports' = number of boundary port sections
  1     'kdport' = port orientation (1=N, 2=S, 3=E, 4=W)
 64     'ifport' = first i-index
 277    'ilport' = last  i-index (=ifport for east/west port)
 697     'jfport' = first j-index
 697     'jlport' = last  j-index (=jfport for north/south port)
  1     'kdport' = port orientation (1=N, 2=S, 3=E, 4=W)
 356     'ifport' = first i-index
 790    'ilport' = last  i-index (=ifport for east/west port)
 697     'jfport' = first j-index
 697     'jlport' = last  j-index (=jfport for north/south port)
  1     'kdport' = port orientation (1=N, 2=S, 3=E, 4=W)
 816     'ifport' = first i-index
 920    'ilport' = last  i-index (=ifport for east/west port)
 697     'jfport' = first j-index
 697     'jlport' = last  j-index (=jfport for north/south port)
  2     'kdport' = port orientation (1=N, 2=S, 3=E, 4=W)
 2     'ifport' = first i-index
 920    'ilport' = last  i-index (=ifport for east/west port)
 2     'jfport' = first j-index
 2     'jlport' = last  j-index (=jfport for north/south port)
  3     'kdport' = port orientation (1=N, 2=S, 3=E, 4=W)
 921    'ifport' = first i-index
 921    'ilport' = last  i-index (=ifport for east/west port)
  2     'jfport' = first j-index
 696    'jlport' = last  j-index (=jfport for north/south port)
  4     'kdport' = port orientation (1=N, 2=S, 3=E, 4=W)
 2    'ifport' = first i-index
 2    'ilport' = last  i-index (=ifport for east/west port)
  2     'jfport' = first j-index
 256    'jlport' = last  j-index (=jfport for north/south port)
  4     'kdport' = port orientation (1=N, 2=S, 3=E, 4=W)
 2    'ifport' = first i-index
 2    'ilport' = last  i-index (=ifport for east/west port)
 287     'jfport' = first j-index
 406    'jlport' = last  j-index (=jfport for north/south port)