[GreenKeys] Re: WW II-Era Computers

[Don Robert House]

Craig,

Thank you very much for sharing this information.  Are images of the  
now working Colossus available on-line?
A video clip would be really impressive!

Best,
Don
K9TTY

On 12 Oct 2007, at 1:27 AM, Craig Sawyers wrote:

...Bletchely Park was using 10 Colossus computers by the end of the  
war to decrypt messages between Hitler's field
commanders and the Berlin bunker.  These used a combination of 2000  
valves (vacuum tubes) and a tape loop that passed the encrypted text  
past a bank of photocells at 60 miles an hour and 5000 characters per  
second.  It took up to 6 hours to calculate the wheel settings of the  
12 rotor Lorenz SZ42 cipher machine.

One Colossus Mk II has been rebuilt at Bletchley by Tony Sale over  
the last 13 years, and works every day for 8 hours, and breaks test  
encrypted messages in 6 hours - the same length of time it takes a  
Pentium PC to break the same message.

Craig