The Cipher Machines and Cryptology website has detailed information and free accurate software simulations of the WW2 German Enigma and U.S. M-209, the Cold War U.S. TSEC/KL-7 and Swiss Hagelin CX-52. The website also covers various other crypto machines and manual ciphering systems, an extensive description of one-time pad systems, numbers stations, the Enigma Challenge, Crypto Box challenge, papers on cryptology,  and much more.

In order to preserve all information, there's also the
Lagacy Edition and the website is also archive by the Internet Archive.

Cipher Machines and Cryptology
 Historical and Technical Information about Crypto Machines, Cryptology and Free Software Simulations
© Dirk Rijmenants 2004 - 2020