Here are some videos on YouTube...
This first one is particularly nice, showing the Nipkow disc getting up to speed, and the picture finally becoming recognizable.
http://www.youtube.com/watch?v=9DFcYRxFdTI
http://www.youtube.com/watch?v=2dmY43KeBuE
I also like this last one, as it gives a good idea that a program in 32 line format can be quite recognisable and entertaining...
http://www.youtube.com/watch?v=osF5gg6RKL4
The above were posted by Eckhard Etzold, whose site is at http://bs.cyty.com/menschen/e-etzold/ar ... ngdisc.htm