What was Colossus and why a virtual one?

Colossus was the name of a series of computers developed by British codebreakers in 1943-1945 to help in the cryptanalysis of the Lorenz cipher. After the war, the Colossus computers were destroyed and all plans and information was required to be incinerated.

In 1992, Tony Sale and his team began the ambitious task of rebuilding a working Colossus from scraps of information and a few photos - they succeeded and you can see this running for real at The National Museum of Computing in Bletchley Park.

Tony Sale also wrote a virtual version of this amazing machine in 2001, but it's real tricky to get running as it was written for a very old version of Internet Explorer.

See www.codesandciphers.co.uk if you want to give it a go.

To honour his memory and to make sure this code and it's story was not lost, I have rewritten from scratch a new Virtual Colossus using current browsers based on his original logic engine code. My hope is that more people will get to know this incredible story about the first computer.