Colossus & Bletchley Park - Computerphile

The Story of Colossus: The World's First Special Purpose Computer

Colossus was a computer built by the British during World War II, designed to crack German codes and communications. One of its creators, Tommy Flowers, had a vision for a new type of machine that could process information quickly and efficiently. At the time, electromechanical technology and relays were being used in bombs and other devices, but Flowers believed that a different approach was needed.

Flowers proposed building a computer using valves, which he thought would be faster and more reliable than existing technology. Despite initial skepticism from others, including senior military leaders who doubted the feasibility of his plan, Flowers persevered. He convinced Max Newman, a mathematician and engineer, to join him in developing the Colossus project. The project's success was crucial to the Allied war effort.

The development of Colossus was a remarkable story of innovation and perseverance. Flowers, an engineer by training, had worked in the research section at Dollis Hill in London before being recruited for the Colossus project. He brought with him his experience working with valves and his knowledge of electronics. Despite concerns about the reliability of valves, which were prone to failure if switched off, Flowers demonstrated their potential through testing and experimentation.

The first test of Colossus took place at Dollis Hill in December 1943. The machine was powered by a team of operators who worked around the clock to process information. The success of this initial test led to further development and deployment of Colossus at Bletchley Park, where it played a critical role in cracking German codes and communications.

Despite its importance, the existence of Colossus remained secret until many years after the war. This secrecy was necessary due to the sensitive nature of the information being processed by the machine. As a result, Flowers and his colleagues were not recognized for their contributions during their lifetimes. It wasn't until the 1980s that the story of Colossus began to be told, and even then, much of the information about the machine's development and deployment remained classified.

In recent years, the Freedom of Information Act has allowed researchers to access previously classified documents related to Colossus. These documents have revealed the remarkable story of Flowers and his team, who worked tirelessly to build and maintain the machine despite the secrecy surrounding their work. The story of Colossus is a testament to the power of innovation and collaboration in times of crisis.

The Development of ENIAC: A Comparison with Colossus

In 1946, an American electronic computer called ENIAC (Electronic Numerical Integrator and Computer) was developed at the University of Pennsylvania. While Colossus had been built two years earlier, its existence remained a secret due to the secrecy surrounding its development. The fact that ENIAC was widely recognized as the world's first special-purpose computer has led some to speculate that Colossus may have been overlooked or undervalued.

However, research has shown that Colossus was indeed the first electronic computer of its kind. While ENIAC was a massive machine, weighing over 27 tons and occupying an entire room, Colossus was significantly smaller and more compact. The comparison between these two machines highlights the ingenuity and resourcefulness of Tommy Flowers and his team.

Despite their contributions to the war effort, Flowers and his colleagues were not recognized for their work until many years after the war. This lack of recognition can be attributed to the secrecy surrounding Colossus's development and deployment. As a result, Flowers was not knighted or awarded other honors that might have been given to him if his work had been more widely acknowledged.

In recent years, however, there has been an effort to rectify this situation. The story of Colossus is now being told in museums and exhibitions around the world, and Flowers's contributions are being recognized for the first time. The development of Colossus is a testament to the power of innovation and collaboration during times of crisis.

The Legacy of Colossus

Today, the legacy of Colossus continues to inspire researchers and engineers around the world. The machine's success in cracking German codes and communications played a critical role in the Allied war effort, and its development marked an important milestone in the history of computer science.

Tommy Flowers and his team at Bletchley Park are now celebrated as pioneers in the field of computer science. Their work on Colossus paved the way for the development of modern computers, and their legacy continues to be felt today. The story of Colossus is a reminder of the power of innovation and collaboration during times of crisis, and it serves as an inspiration to researchers and engineers around the world.

In conclusion, the story of Colossus is a remarkable one, marked by innovation, perseverance, and collaboration. Despite the secrecy surrounding its development and deployment, the machine's legacy continues to inspire researchers and engineers today. The fact that Flowers was not recognized for his contributions during his lifetime is a testament to the challenges of working in a secretive environment, but it has also led to a renewed appreciation for his work and the importance of Colossus in the history of computer science.

"WEBVTTKind: captionsLanguage: enhere we are at Bletchley Park but in a part of The Bletchley Park site that's the national museum of computing in the UK and they've had the sense to have the sighting here for the rebuild of the Colossus machine that was as many of you know the big feature of Bletchley Park later on in the war because it was involved in helping to decrypt the Laurent Cipher which was a much much bigger challenge than even Enigma is there much to see yes there's quite a lot to see you got to remember this is arguably the world's very first uh electronic computer it really is largely electronic it uh relies on thermionic valves that's vacuum tubes to those of you in North America um so yes the the logic and the counting is done with vacuum tubes the feature though of computers of this era and it is a special purpose computer remember it's not general purpose and the one thing that was very difficult was to get them to have memory because memory hadn't been invented so the data that it has to analyze is actually on a five hole paper tape and you just have it spinning around at very high speed and if you miss a particular piece of data you have to wait for it to come around again so that tape that you see there is going at 5,000 characters per second let's get over there and have a look yep 5,000 characters per second roughly I think corresponds to 30 mph and it is absolutely amazing that it does not fly apart there is one problem of joining the ends of the tape and Phil over there who's the expert tells me that whereas in the second world war they used to use a Benzene based uh Bostic sort of glue health and safety won't permit that anymore and it's highly inflammable and so he's just been doing he tells me some experiments on what the best uh substitute would be for joining tape ends answer number one was that brown parcel tape which worked quite well answer number two which is just tried out I think is prit stick and prit stick just superb so there we are then continuous readout of data quite a high latency because if you miss something you've got to wait for it to come around again but all of the electronics here it's dedicated its special purpose it's recognizing patterns in the cipher text that came off the Lorent Cipher machine and once you specified whatever the patterns you're looking for it will do the automatic counting for you the Loren machine was basically an adapter that you could add on to a teleprinter we've heard all about Enigma which in many ways was a very low-level very labor intensive machine Hitler wanted something faster more personal more secure so the Lorent machine was used by the high command to talk to each other it was used by Hitler to give commands to his generals it was crucial roundabout D-Day to be able to decrypt the Lorent traffic because essentially it did show that Hitler had been taken in by an Allied plan to convince him that D-Day wasn't going to happen in Normandy but there was a whole how shall we say faint operation to say no no no let's try and con the Germans it's going to happen in Cal and they found out by decrypting Lawrence traffic using Colossus Mark 2 that yes Hitler had fallen for this deception and kept on C generals no no no you know it's not going to be in Normandy it's going to be in the padal that according to military people made a world of difference about the level of opposition they faced and how quickly the Advan across Germany could take place after D-Day Well what we'll find in more detail later on with all of these valves is this is why it really is thought of as one of the world's first special purpose valve driven computer Tommy flowers was its famous designer and people said to him at the time flowers what are you proposing what's wrong with electromechanical technology relays you know like in the bomb and basically Tommy said look for the job we have to do with a Lawrence Cipher it's not going to be fast enough I'll build it for you using valves and then people said but how many will you need flowers you know six valves a dozen he said 1,500 and here we have them and he was not afraid of valves he didn't mind how many he used people when they said to him but flowers come come come we all know about thionic valves they blow and they go bang and you have to replace them they're not reliable enough and he was basically a post office telecoms engineer and he said look I've worked in the research section I've LED it valves are fine so long as you never switch them off they they've got heaters in there of course and uh so long as maybe at you know when it's not working flat out you turn the heating voltage down but don't switch it off you will be surprised how reliable it can be and he was proved right it was tested out at Tommy's own place dollis Hill in late 43 I think it's been established it was on 8th of December 1943 dollis Hill testing moved to actuallyy Park here in early 1944 and uh came into action pretty soon thereafter this is a replica is it this is a replica yes as a result I think of the Freedom of Information Act in America it was possible to get hold eventually I think of a complete set of drawings wasn't flowers very much an unsung hero yes he did suffer because first of all people wouldn't believe him then when he did deliver of course he was a hero but was effectively felt that he would would never get his Just Desserts of of Fame and and all that because of the secrecy it's hard to believe now how Ultra Ultra Ultra secret this was and uh I think it was very hard for Tommy when later on I think it was about 1946 there was an American electronic special purpose computer came along called eniac which calculated Gunnery trajectories now of course since nobody knew anything about Colossus this has been widely reported as the world's first special purpose computer with valves this was 2 years earlier than Inc but nobody could say a word about it not a word and I think a lot of people at Bletchley still felt at the end of the war that frankly Tommy flowers Max Newman who was the head of the Newry here which was in charge of all this and the guy who made the real one of the real initial analyses that enable Clos to be build built chat called Bill Tut they should all have been knighted um they weren't they got various sort of awards and so on the only good spin I can put on this as to why they weren't honored more is the secrecy again I can just imagine the whiteall civil servants say look if we start nighting all these people they're going to start asking questions the public why there's flowers superb engineer but why an idol why you know and don't forget this was in an era up until about fairly recently where the whole idea was that this should be kept secret for ever they didn't want it ever to come out or I think Winston J's compromise was something like a 100 years could you imagine having to wait until 2045 or 2044 for this to be made available anyway Common Sense has now prevailed I'm glad to say and it's a wonderful thing to behold it really is flowers said one of the best days of my life was seeing all these clever people Alan churing Max Newman Bill Tut all of them with their mouths dropping open saying flowers what have you done and I think you said the worst bit after that was this is wonderful this is so quick now we can really get working um flowers we' like four more of these preferably in two months time and I don't think people said get real in early 1944 but that was the sentiment effectively 0 2 1 and so on and the important thing about this is by doing this we're going to get a huge list of norts all in a row and that is very easily compressed by Huffman encodinghere we are at Bletchley Park but in a part of The Bletchley Park site that's the national museum of computing in the UK and they've had the sense to have the sighting here for the rebuild of the Colossus machine that was as many of you know the big feature of Bletchley Park later on in the war because it was involved in helping to decrypt the Laurent Cipher which was a much much bigger challenge than even Enigma is there much to see yes there's quite a lot to see you got to remember this is arguably the world's very first uh electronic computer it really is largely electronic it uh relies on thermionic valves that's vacuum tubes to those of you in North America um so yes the the logic and the counting is done with vacuum tubes the feature though of computers of this era and it is a special purpose computer remember it's not general purpose and the one thing that was very difficult was to get them to have memory because memory hadn't been invented so the data that it has to analyze is actually on a five hole paper tape and you just have it spinning around at very high speed and if you miss a particular piece of data you have to wait for it to come around again so that tape that you see there is going at 5,000 characters per second let's get over there and have a look yep 5,000 characters per second roughly I think corresponds to 30 mph and it is absolutely amazing that it does not fly apart there is one problem of joining the ends of the tape and Phil over there who's the expert tells me that whereas in the second world war they used to use a Benzene based uh Bostic sort of glue health and safety won't permit that anymore and it's highly inflammable and so he's just been doing he tells me some experiments on what the best uh substitute would be for joining tape ends answer number one was that brown parcel tape which worked quite well answer number two which is just tried out I think is prit stick and prit stick just superb so there we are then continuous readout of data quite a high latency because if you miss something you've got to wait for it to come around again but all of the electronics here it's dedicated its special purpose it's recognizing patterns in the cipher text that came off the Lorent Cipher machine and once you specified whatever the patterns you're looking for it will do the automatic counting for you the Loren machine was basically an adapter that you could add on to a teleprinter we've heard all about Enigma which in many ways was a very low-level very labor intensive machine Hitler wanted something faster more personal more secure so the Lorent machine was used by the high command to talk to each other it was used by Hitler to give commands to his generals it was crucial roundabout D-Day to be able to decrypt the Lorent traffic because essentially it did show that Hitler had been taken in by an Allied plan to convince him that D-Day wasn't going to happen in Normandy but there was a whole how shall we say faint operation to say no no no let's try and con the Germans it's going to happen in Cal and they found out by decrypting Lawrence traffic using Colossus Mark 2 that yes Hitler had fallen for this deception and kept on C generals no no no you know it's not going to be in Normandy it's going to be in the padal that according to military people made a world of difference about the level of opposition they faced and how quickly the Advan across Germany could take place after D-Day Well what we'll find in more detail later on with all of these valves is this is why it really is thought of as one of the world's first special purpose valve driven computer Tommy flowers was its famous designer and people said to him at the time flowers what are you proposing what's wrong with electromechanical technology relays you know like in the bomb and basically Tommy said look for the job we have to do with a Lawrence Cipher it's not going to be fast enough I'll build it for you using valves and then people said but how many will you need flowers you know six valves a dozen he said 1,500 and here we have them and he was not afraid of valves he didn't mind how many he used people when they said to him but flowers come come come we all know about thionic valves they blow and they go bang and you have to replace them they're not reliable enough and he was basically a post office telecoms engineer and he said look I've worked in the research section I've LED it valves are fine so long as you never switch them off they they've got heaters in there of course and uh so long as maybe at you know when it's not working flat out you turn the heating voltage down but don't switch it off you will be surprised how reliable it can be and he was proved right it was tested out at Tommy's own place dollis Hill in late 43 I think it's been established it was on 8th of December 1943 dollis Hill testing moved to actuallyy Park here in early 1944 and uh came into action pretty soon thereafter this is a replica is it this is a replica yes as a result I think of the Freedom of Information Act in America it was possible to get hold eventually I think of a complete set of drawings wasn't flowers very much an unsung hero yes he did suffer because first of all people wouldn't believe him then when he did deliver of course he was a hero but was effectively felt that he would would never get his Just Desserts of of Fame and and all that because of the secrecy it's hard to believe now how Ultra Ultra Ultra secret this was and uh I think it was very hard for Tommy when later on I think it was about 1946 there was an American electronic special purpose computer came along called eniac which calculated Gunnery trajectories now of course since nobody knew anything about Colossus this has been widely reported as the world's first special purpose computer with valves this was 2 years earlier than Inc but nobody could say a word about it not a word and I think a lot of people at Bletchley still felt at the end of the war that frankly Tommy flowers Max Newman who was the head of the Newry here which was in charge of all this and the guy who made the real one of the real initial analyses that enable Clos to be build built chat called Bill Tut they should all have been knighted um they weren't they got various sort of awards and so on the only good spin I can put on this as to why they weren't honored more is the secrecy again I can just imagine the whiteall civil servants say look if we start nighting all these people they're going to start asking questions the public why there's flowers superb engineer but why an idol why you know and don't forget this was in an era up until about fairly recently where the whole idea was that this should be kept secret for ever they didn't want it ever to come out or I think Winston J's compromise was something like a 100 years could you imagine having to wait until 2045 or 2044 for this to be made available anyway Common Sense has now prevailed I'm glad to say and it's a wonderful thing to behold it really is flowers said one of the best days of my life was seeing all these clever people Alan churing Max Newman Bill Tut all of them with their mouths dropping open saying flowers what have you done and I think you said the worst bit after that was this is wonderful this is so quick now we can really get working um flowers we' like four more of these preferably in two months time and I don't think people said get real in early 1944 but that was the sentiment effectively 0 2 1 and so on and the important thing about this is by doing this we're going to get a huge list of norts all in a row and that is very easily compressed by Huffman encoding\n"