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Day out to the National Museum of Computing, Bletchley.

What a day at The National Museum of Computing at Bletchley. Just on the outskirts of Milton Keynes, we have all heard of Bletchley Park and the quest to decipher the German Enigma coding during World War Two. For me, it was across the car park in the army huts that housed the National Museum of Computing where the big story was hiding, and for some reason, one that is somewhat untold.


flickrSLiDR/ Bletchley Park Album

The story starts at Capel-le-Ferne, Kent

In the first part of the museum I was surprised to see the name of the village in Kent where I went to primary school. Capel-le-Ferne was a lofty inhospitable place set between the Dover and Folkestone cliffs. (It was there where I fell in love with the tenor saxophone and developed my hate for swede). It was one of a series of coastal gun batteries and signal centres in the South East. People worked there on the look out and listen out for German bombers, and they would direct messages via telephone or teleprinter to the air base in nearby Hawkinge to launch the Spitfires and Hurricans to attack. I came across this story on the web by Dalma Flanders about her time in the WAAF’s Intelligence Service and she was stationed in Capel living with a civilian family. Dalma listened in, deciphered code, and passed on messages. She spoke German and later was trained in Dutch.

The German codes always had a strict pattern and they were never particularly difficult to break.

Over to Bletchley, Berkshire

At Bletchley Park was another signal centre but on a different scale. The Bletchley Park old house was where short messages were received and decoded. The man in the museum likened these Bletchley codes to WW2 Tweets. In the buildings that are now part of the National Museum of Computing it was quite a different matter, and entire German plans and strategy documents of up to 10,000 characters were received and ultimately decoded.

Initially, attempts at decoding were all done by hand with equal teams of men and women working around the clock to listen in, record and translate two-tone signals. These were strategic documents relayed between German army officers and Hitler, and unlike Enigma where the nature of the coding machine was understood before the war, the German mechanisms for scrambling these long documents was totally unknown. Hence, the process started in 1939 and it wasn’t until 1944 where the first breakthrough was made.

How did it all work? The two-tone signals were manually turned into a visual trace and then converted to what looked like ticker-tape made of sequences of five holes. The tape was just a visual representation of the code – there was additional activity to decipher these codes. Ultimately, machines would be designed to read these tapes and do the deciphering, and manual conversation from audio signal to message could take from 6 to 8 weeks, by which time the information was possibly no longer valuable.

Bill Tutte and the Code Breakers

We may all be familiar with the brilliance of Alan Turing breaking the Enigma Code, but Bill Tutte was formidable in breaking what was known as the Lorenz Cipher. Imagine, hours and hours of audio signal, miles of paper ticker tape, and how the brain power of Bill and other mathematicians not just began to decipher, but design a replica of the Lorenz Cipher machine used to scramble the code by the Germans is  quite unfathomable. But there was a break through in 1944. The German signaller sending the message made a mistake and had to resend. Second time around he included abbreviations and shortened words. Not only did the vigilant decoders spot a duplicate message, they realised that each new message had a “starter” phrase, and they could then look out for these. This reminds me of DNA code, where there are short snippets of code announcing the start of the important message or information.

From these vague clues, Bill and his team broke the entire code. Now they could do it, they needed to try and be faster.

The Birth of Computers and Tommy Flowers

Tommy Flowers was an electronic engineer who worked at the GPO (General Post Office). The GPO then went on to form British Telecom and the Post Office as we know it today – if anyone remembers the yellow GPO vans and the red Post Office vans? Here my understanding of the electronics fails me, but Tommy ultimately designed a computational machine, using valves, that could read and decode the ticker tape at a much faster speed. Based on binary data and simple logic, the early computers were born. I’m sure I do injustice to what is a great and elegant story. (Images of Colossus, the first computer, and the tape can be seen in the Flickr gallery at the top of the page).

The Destruction of Colossus!

Below was an early iteration of Colossus in what was known as the Tunny (Tuna) Room. The machine went through several iterations and when it began successfully decoding German strategic plans in 1944, it started to have a big impact on the direction of the war and crucially saved lives – on both sides. For  vital manoeuvres such as Normandy, the machine helped keep tabs on advancing German troops, and the crucial decision to bring the event forward was made.

Tunny Room Computer
Tunny Room early Colossus. Animated GIF – you may need to click on the GIF to see it animate in it’s full glory!

A later machine – Colossus Mark II advanced the code breaking process and is housed in the Colossus Room at the Museum. Understandably, after the war all traces of the machines were destroyed. Many years later, permission was given to write a book, and a series of photographs within it prompted people who had worked on the machine to come forward. They set forth in 2002 to rebuild it from plans and photographs, and in 2013 the final – operational – machine was complete. The task was made simpler by the fact all the parts were standard issue GPO components. I personally think the rebuild of the machine is as remarkable and as fascinating as building it in the first place.

Colossus Oscilloscope
Colossus Oscilloscope – an animated GIF that you may need to click on to view in a new window. Oh, go on, you know you want too!









What Next for Computers?

The National Museum of Computing, and its truly brilliant and enthusiastic staff, go on to tell the tale of the history of computing. Early computers were introduced into banking and insurance, and another notable example belonged to a chicken farmer to provide data and perform calculations on the flock and egg production. The gentleman in the room proudly tells us that all the machines in “his” room are operational still today!

In other areas of the museum, the notion of equal opportunities continued, with men and women playing vital roles during the war and then in the development of these machines afterward. The construction of what I think were memory blocks the size of a toaster was by female embroiderers and lace makers who had the dexterity and the patience to weave the wire into the intricate designs required.

Over to the Dekatron!

By this point in the museum I was totally enthralled by the beauty of the machines. The electronics and processes are visualised through flashing lights – all meaning something I guess, and enabling the engineers to monitor the process of the code reading and deciphering, and also to pin-point faults.

The Dekatron has a name straight out of science fiction was another calculating machine with a beautiful array of flashing lights and accompanying sounds. The operator here was clearly at one with the machine and knew every nuance of it. Each valve rotated in a position from 1 to 9 to process a series of calculations. The rest is beyond my comprehension and is best left to the imagination.

Dekatron. Click to see the animated GIF.










Milton Keynes Best Kept Secret!

It seemed ironic that a museum of computing did not provide you with devices and ear phones, and there were no whizzy multimedia exhibits that you find in other museums. NO! It was much better than that because of the stories told by the amazing people who worked in the museum. I am convinced each was in love completely with his computer.

One of the fascinating stories was that during the war and until quite recently the story and importance of Bletchley Park was completely confidential. The museum guide told the story of canteen staff who during the war were specially chosen and maintained confidentially of any conversations that may have overheard. And the canteen was open 24 hours a day, so that is a fair amount of chatter!

When I posted these photographs on Facebook I heard from a fellow saxophone player who grew up in Bletchley and actually worked in the same canteen in the 1960s. Incredibly even then he had no idea what went on there, and neither did the people in the town of Bletchley. It was years later when it opened as a museum that he realised the significance of where he had worked. Here is what Graham said – and believe me he WOULD chat to anyone and is actually a lecturer in  computing today.

Yes we lived just round the corner and people said it was to do with the Diplomatic Wireless Service  … whatever that was.   I must have worked in the canteen in the summer of 1967 or 68.  It was outside the perimeter fence and they came out for lunch.  I did a lot of clearing tables and so I chatted to everyone,  but no one ever discussed anything about what went on inside.

It was really top secret. No one in the canteen ever told me what they did and I never spoke to anyone who knew what went on there. I was amazed when I visited it with my brother a few years ago.

The old house was owned by some old geeser before the war who had some sort of issue with my great grandfather.  Whenever  his name was mentioned ( the secondary modern school was named aftter him) thing went quiet.  However, my parents were really close friends with his chauffeur’s daughter.

This was another world.