Sorry it has been a while coming but I have just finished part two of
NFB 101. I found I could not describe it properly without diagrams and
proper equations so I had to resort to using a word processor and
converting the result into a pdf, all of which took time. So point your
browser here: http://www.ianbell.ukfsn.org/data/nfb101.pdf
to download it.
Cheers
Ian