I've also maintained a bit of an amateur interest in cryptography. While I understand a bit about modern ciphers such as DES, IDEAL and RC4, I find it more fun to play with older cryptosystems. When Simon Singh published his book The Code Book, I decided to work through the Cipher Challenge at the back. While I didn't win the $10,000 prize, I did manage to crack 7 out of 10 ciphers, including the Playfair, ADGVX cipher and the German Enigma machine (which took the most work and was the most fun). I still am fascinated by old crypto machines. My friend Jeff actually owns an M209 field cipher machine, which I dug up a simulator for out of the old Version 6 Unix distribution.
Anyway, while scanning
sci.crypt, I ran accross this interesting link to a paper simulation of the 3 rotor German Enigma machine. If
I had this while I was debugging my simulator, it probably would have shaved several weeks off my efforts. Much thanks to Michael Koss, who is a collector
of crypto machines, and to John Malley for putting some of the photos of his collection up on the net. I'm completely jealous.
I've always been interested in robotics (particularly of the amateur variety) and
in the past few days I've discovered some excellent links. Slashdot ran an
article recently that highlighted the Legway, a lego version
of the Segway, built using the RCX controller from a Lego Mindstorms kit. It's an
awesome achievement, and very, very spiffy. David Anderson has an incredible home built robot called nBot, which is a
self balancing two wheeled robot. His page is great, with links to a lot of great pictures, video and details about implementation. He also has a nice machine shot where he manufactures these cool robot parts. Truly inspirational.
Larry Barello has a nice page describing his Gyrobot which has a similar control mechanism. Very nice indeed. This page links to a number of MPEG movies of JOE, a self balancing radio controlled robot. They also have a nice paper describing the
implementation and I'm told it's a subset of their thesis work, which is unfortunately in Italian.
Cool, cool stuff.