1 00:00:00,000 --> 00:00:28,014 [music] 2 00:00:28,045 --> 00:00:31,674 Today, we're at Bletchley Park in honor of Alan Turing's 100th birthday. 3 00:00:31,674 --> 00:00:36,304 Bletchley Park, just north of London, in between Cambridge and Oxford, was 4 00:00:36,304 --> 00:00:40,165 considered by many as the birthplace of modern computer science. 5 00:00:40,165 --> 00:00:46,015 In 1938, again in anticipation of war, the Government Code and Cypher School through, 6 00:00:46,015 --> 00:00:50,040 in, in the main, their operational director a gentleman called Alastair 7 00:00:50,040 --> 00:00:55,014 Denniston, had drawn up a list. He had sent two people out to troll through the, 8 00:00:55,178 --> 00:00:59,753 people at Oxford and primarily Cambridge and to some extent Oxford and drew up a 9 00:00:59,753 --> 00:01:05,073 list of people who they approached who agreed in the event of war would report 10 00:01:05,073 --> 00:01:09,636 immediately to Bletchley park [inaudible] declared war on September third 1939. The 11 00:01:09,636 --> 00:01:14,758 following day, September fourth during and several others reported to Bletchley Park. 12 00:01:14,758 --> 00:01:20,705 As the requirement for more people was needed some, predominately a gentleman 13 00:01:20,751 --> 00:01:24,238 called Gordon Welchman, who had been on the initial list, he'd arrived the same 14 00:01:24,238 --> 00:01:28,879 day as Turing, he want back to Cambridge and he started recruiting all his best 15 00:01:28,879 --> 00:01:33,578 students and in effect what they created here was the world's first [inaudible], a 16 00:01:33,578 --> 00:01:38,339 secretive organization where there were no rules, eventually their main benefactor 17 00:01:38,339 --> 00:01:42,963 became the prime minister Winston Churchill and they persuaded Churchill 18 00:01:42,963 --> 00:01:48,659 that this place needed more resources. Churchill agreed, and he wrote a famous, a 19 00:01:48,659 --> 00:01:54,468 letter was written by Welchman, Turing and the two deputies to Churchill. 20 00:01:54,468 --> 00:01:57,641 And one of their number, a gentleman called [inaudible] actually delivered it in 21 00:01:57,672 --> 00:02:01,528 person to Downing Street. Churchill amazingly read the letter the same day it 22 00:02:01,528 --> 00:02:05,911 was delivered. He put a famous action to stay stamp on it, with a handwritten note 23 00:02:05,911 --> 00:02:10,311 to his chief of staff, a chief called General Ismay, which said expedite with 24 00:02:10,311 --> 00:02:14,711 extreme priority, and report to me when it is done. And really, from that point, 25 00:02:14,711 --> 00:02:19,430 September 1941 Bletchley Park got all the resources they needed. They threw, in 26 00:02:19,430 --> 00:02:24,310 effect, the smartest people together in Britain and said, here's a budget, this is 27 00:02:24,310 --> 00:02:29,077 the endgame and that's why they invented some of these technologies which probably 28 00:02:29,077 --> 00:02:33,492 wouldn't have been invented for years. ≫> In many ways, Bletchley Park was 29 00:02:33,492 --> 00:02:37,764 an early version of a multidisciplinary science center, much like CERN or NCSA is 30 00:02:37,764 --> 00:02:41,645 today. Many brilliant people, with different skills and backgrounds were 31 00:02:41,645 --> 00:02:46,724 brought together to solve difficult problems. The combination of the skills 32 00:02:46,724 --> 00:02:50,444 and collaborative environment, resulted not in just solving the problems of 33 00:02:50,444 --> 00:02:55,806 cryptography that they were facing. But in addition solved broader problems for all 34 00:02:55,806 --> 00:02:59,809 of computing and all of society. ≫> When the people arrived here, they knew 35 00:02:59,809 --> 00:03:05,969 when they arrived the Germans had taken a machine a machine which we tend to call 36 00:03:05,969 --> 00:03:10,080 Enigma. Enigma was a particularly a very [inaudible] encryption machine. That 37 00:03:10,080 --> 00:03:14,786 machine was modified from the commercial version. And it allowed them to encrypt 38 00:03:14,786 --> 00:03:18,939 messages. This was going to become a machine to be used for operational 39 00:03:18,955 --> 00:03:24,729 communications. Very short 200, 250 character messages. Hitler had conceived 40 00:03:24,729 --> 00:03:28,623 and his generals a type of warfare never seen before which became known as 41 00:03:28,623 --> 00:03:33,661 Blitzkrieg. Very fast movement 50 miles a day. Particularly when they invaded France 42 00:03:33,661 --> 00:03:36,059 and, and the latter stages of their invasion of Poland. You couldn't use 43 00:03:36,059 --> 00:03:41,236 fixed line communication. You needed to use wireless communications. Here was a device 44 00:03:41,236 --> 00:03:46,228 which was portable. Weight 25 pounds. Ran of a battery. You could encrypt messages 45 00:03:46,228 --> 00:03:50,009 and then in a separate process they could be sent using the fairly new technology of 46 00:03:50,009 --> 00:03:54,043 wireless radio. It was the Poles who were the first to recognize that the age of 47 00:03:54,043 --> 00:03:58,044 machine cryptography had arrived, and the sort of people who would be good at 48 00:03:58,044 --> 00:04:02,330 dealing with it were mathematicians. In fact, they even went so far as to put on a 49 00:04:02,330 --> 00:04:07,576 course on cryptography at the University of Poznan invited twenty or 30 young 50 00:04:07,576 --> 00:04:10,839 German-speaking mathematicians to enroll. It was a very difficult course and by the 51 00:04:10,839 --> 00:04:15,037 time the course was finished, there were really only three graduates who they 52 00:04:15,037 --> 00:04:19,017 recruited, their names were Marian Rajewski, Henry Zygalski and Jerzy 53 00:04:19,017 --> 00:04:23,402 Rozycki. And these three were the core of this team, and, they are the ones who 54 00:04:23,402 --> 00:04:27,271 really made the early breakthroughs. They convened a conference. At their secret 55 00:04:27,271 --> 00:04:32,416 headquarters. This was actually July 39. And at that conference, they gave the 56 00:04:32,416 --> 00:04:36,720 British everything, they revealed what they had done, they gave them a replica of 57 00:04:36,720 --> 00:04:41,133 the Enigma machine and all of their work. That information came back to Bletchley Park 58 00:04:41,133 --> 00:04:45,606 and once they were established in Bletchley Park, they then used the Polish 59 00:04:45,606 --> 00:04:49,856 method to break the Enigma machine. The Poles had actually built some machines 60 00:04:49,856 --> 00:04:53,830 themselves. One of which was called a Bomba. Now, that machine, the name 61 00:04:53,972 --> 00:04:57,879 apparently comes from a Polish ice cream dessert of the same name. So in effect, 62 00:04:57,879 --> 00:05:02,840 vanilla ice cream with chocolate sauces. Around it >> This machine was called 63 00:05:03,056 --> 00:05:09,087 in honor of what the Poles did. But the Poles' technique was based on a particular 64 00:05:09,087 --> 00:05:14,479 way that at that time the Germans enciphered their messages. They, at that 65 00:05:14,479 --> 00:05:19,283 point, were repeating the message header, and that was the attack which the Poles 66 00:05:19,283 --> 00:05:23,046 developed on it. They believed correctly that when, when the war would start, that 67 00:05:23,046 --> 00:05:28,334 the Germans would change the way, the way they were doing that and they called for 68 00:05:28,334 --> 00:05:33,838 help. They told Turing and the people here everything they have done, which we are 69 00:05:33,838 --> 00:05:38,996 and should be very grateful. But they also proved that it was possible. And that, I 70 00:05:38,996 --> 00:05:45,168 think was the spur that kicked the Brits into actually doing something about it. 71 00:05:45,168 --> 00:05:50,466 Now, Turing understood the weaknesses of the way they'd done it and developed a 72 00:05:50,466 --> 00:05:55,967 trip-based mechanism based on the fact that every military organization in the 73 00:05:55,967 --> 00:06:01,167 world cannot stop itself sending stereotyped messages. He even talked to a 74 00:06:01,167 --> 00:06:06,947 brilliant team of engineers led by Dr. Keene who told him roughly the speed that 75 00:06:06,947 --> 00:06:12,379 it would be possible to examine potential stops for. Between, between them, they 76 00:06:12,379 --> 00:06:17,904 then designed the, the machine called bomb which would look for that and do so in 77 00:06:17,904 --> 00:06:24,175 sensible time. Here is an , example where we have intercepted this message S N M K 78 00:06:24,175 --> 00:06:29,156 G. We're pretty sure that, that is, because this particular operator always 79 00:06:29,156 --> 00:06:33,446 did this, this is his morning weather forecast. So here we have the guessed 80 00:06:33,446 --> 00:06:38,188 German plain text [foreign] weather forecast and the two are lined up. At that 81 00:06:38,188 --> 00:06:43,724 point the Enigma's ability, or inability to encode a letter as itself is useful 82 00:06:43,724 --> 00:06:48,584 because you can make sure you've got no clashes here. And from these guest 83 00:06:48,584 --> 00:06:55,523 letters, we, the trip makers would derive a picture like this called a menu where, 84 00:06:55,523 --> 00:07:01,705 you'll notice that, that position starts at E here. G is encoded as E. So we have G 85 00:07:01,705 --> 00:07:08,278 going to E. It starts at P at the end here. E goes to V. This is reversible of 86 00:07:08,278 --> 00:07:15,043 course. We can describe this other way around. So here's E to V that's ZZG here. 87 00:07:15,043 --> 00:07:22,724 S is going to A. So, S is going to V, excuse me. So, here's another link. And 88 00:07:22,724 --> 00:07:28,540 eventually we can go all the way around, and we can close this loop. Like that. It 89 00:07:28,540 --> 00:07:33,558 was the closed loops that they were looking for. The operation of the bomb was 90 00:07:33,558 --> 00:07:38,912 simply that if there is a letter which you can feed in at this point. And which comes 91 00:07:38,912 --> 00:07:43,602 around though a string of one, two, three, four, five, six enigmas and comes back as 92 00:07:43,602 --> 00:07:48,788 that same letter, then it's possible the position of these wheels match the 93 00:07:48,788 --> 00:07:54,700 position of the wheels when Gunter started encoding his message on his enigma. It 94 00:07:54,700 --> 00:08:00,359 turned out to be a bit more picky about loops and menus than, perhaps they had 95 00:08:00,359 --> 00:08:06,145 hoped, although it worked. And at that point, Welchman added a completely left 96 00:08:06,145 --> 00:08:11,650 field master stroke called the diagonal board which I think is fair to say made, 97 00:08:11,650 --> 00:08:16,309 the difference between success and failure to Turing's original idea. And here lies 98 00:08:16,309 --> 00:08:21,171 three diagonal boards. That's one, that's the other. This is the third one, hiding 99 00:08:21,171 --> 00:08:26,380 in place where you can't see it. But can, can you see Z down to A? Okay? There's 100 00:08:26,380 --> 00:08:31,254 nothing connecting that to the machine. It's just bolted there for convenience. 101 00:08:31,254 --> 00:08:35,485 The only connections to the machine are when you connect x into one of the 102 00:08:35,485 --> 00:08:39,906 enigmas. So, what'll happen is, when we turn the machine on, you'll see it , it 103 00:08:39,906 --> 00:08:45,342 will run up to speed, okay? The, the, the motor will be running, and the clutch will 104 00:08:45,342 --> 00:08:50,722 drop in. Then, we'll see the various carry mechanisms happening. Then when we stop 105 00:08:50,722 --> 00:08:56,424 the machine, you'll see it slow down. And then the clap shot's up. So, Tony, if 106 00:08:56,424 --> 00:09:15,157 you'd run it up for us please. That's going. It's going. Could you turn on 107 00:09:15,157 --> 00:09:33,747 [inaudible] hose please? Okay. Thank you.So, what you saw there was the middle 108 00:09:33,747 --> 00:09:40,346 carry, then we switched on carry home to make the slow carry work all the time. So, 109 00:09:40,346 --> 00:09:47,782 these bars are just pushing around all the drums. And you can see that all the 36 110 00:09:47,782 --> 00:09:53,760 Enigmas are just in step. They're all just turning and they are a resource. These are 111 00:09:53,760 --> 00:09:59,518 the very fast relays, the three banks or actually four for the chains due to the 112 00:09:59,518 --> 00:10:05,997 detection. Yeah. This is the control logic. Okay. And then these this is the 26 113 00:10:05,997 --> 00:10:11,374 bit register that notes a stop and then allows the machine to slow down before it 114 00:10:11,374 --> 00:10:16,407 stops the [inaudible]. That, our favorite statistic is the sheer amount of wire in 115 00:10:16,407 --> 00:10:21,451 the thing. We've lost count but it's somewhere between ten and twelve miles of 116 00:10:21,451 --> 00:10:25,523 wire in each one of these. ≫> Germans really, there was two main systems 117 00:10:25,523 --> 00:10:30,463 they were using. Enigma was their operational system. That was being used 118 00:10:30,463 --> 00:10:34,648 for all specific operational communications. Again, very short, maximum 119 00:10:34,648 --> 00:10:40,038 of 250 characters. Instructions, orders for Panzer division to move from one 120 00:10:40,038 --> 00:10:45,039 location to another or for a submarine to attack a convoy, an aircraft, to, during 121 00:10:45,039 --> 00:10:50,062 the Battle of Britain to attack specific targets. The Germans started to introduce, 122 00:10:50,062 --> 00:10:55,079 through probably 1941, a different system. The intercept service which Britain had 123 00:10:55,079 --> 00:11:00,282 put into place, to intercept these messages started hearing traffic which was 124 00:11:00,282 --> 00:11:04,983 clearly not Enigma traffic. Enigma traffic was Morse Code, easily identifiable. 125 00:11:05,192 --> 00:11:10,571 People can be trained fairly simply to transcribe, to listen to Morse Code and 126 00:11:10,571 --> 00:11:15,657 transcribe the letters. This was a totally different signal, it was not discernible, 127 00:11:15,657 --> 00:11:20,161 it was not transcribable, this was Adolf Hitler's communication channel, betw een 128 00:11:20,163 --> 00:11:25,173 his army generals. So, very long winded, communications, top secret, and so this 129 00:11:25,173 --> 00:11:29,781 was, an even more daunting task, arguably, then in England, because this encryption 130 00:11:29,781 --> 00:11:35,043 machine that was used with this system there were various ones of them Hitler 131 00:11:35,043 --> 00:11:40,351 referred to these as Geheimschreiber, his secret writers, several companies, Seimens 132 00:11:40,552 --> 00:11:45,087 that exists today, making, were making machine Hagland, but there was also the 133 00:11:45,087 --> 00:11:49,870 Lorenz company. And that was a primary machine particularly Lorenz Desk Set 42. 134 00:11:50,063 --> 00:11:55,114 That machine, and unlike Enigma that had three encryption wheels have twelve 135 00:11:55,116 --> 00:11:59,903 encryption wheels. They approached the post office research lab at Dulles Hill in 136 00:11:59,903 --> 00:12:04,923 London, a young engineer called Tommy Flowers went into the project he was in 137 00:12:04,923 --> 00:12:09,838 effect told, well, go ahead, if you can get approval. Flowers go back to the post 138 00:12:09,838 --> 00:12:15,838 office, got approval, put a small card team together, and in less than a year had 139 00:12:15,838 --> 00:12:20,050 a working prototype, quite a remarkable achievement. The first Colossus as this 140 00:12:20,050 --> 00:12:24,232 machine became known to mark one had 1,500 valves or vacuum tubes in it. And it, it 141 00:12:24,232 --> 00:12:27,901 brought in the Bletchley Park at work almost straightaway. The people here were 142 00:12:27,901 --> 00:12:32,776 convinced, they asked for a more powerful computer. Flowers had already anticipated 143 00:12:32,776 --> 00:12:36,981 this, he already had it in production. 2,500 valves in a era when no machine had 144 00:12:36,981 --> 00:12:41,821 more, that used valves had more than about fifteen, here was a machine with two and 145 00:12:41,821 --> 00:12:47,115 one-half thousand. Flowers was told that they needed the Mark too by June first 146 00:12:47,115 --> 00:12:51,577 1944 because there was a certain date in the diary. June 5,1944 was the schedule 147 00:12:51,577 --> 00:12:55,468 date for Operation Overlord D-day. They had actually ended up in June sixth 148 00:12:55,471 --> 00:13:00,069 because of bad weather Flowers delivered the mark, the first mark to the Bletchley 149 00:13:00,069 --> 00:13:04,070 Park on June first. They switch it on, it worked straightaway. They immediately 150 00:13:04,070 --> 00:13:08,075 started decrypting messages between the German high command, and much to their 151 00:13:08,075 --> 00:13:13,012 delight, delight, they discovered that all of the subterfuge about the D-Day landings 152 00:13:13,012 --> 00:13:17,033 had worked. Hitler believed that the main invasion was going to be at t he port in 153 00:13:17,033 --> 00:13:21,044 Calais not at Normandy. That intelligence was fed back to General Eisenhower at 154 00:13:21,044 --> 00:13:25,060 Allied Screen Command Headquarters, and there is reasonable evidence to conclude 155 00:13:25,060 --> 00:13:30,001 that D-Day might have not gone ahead on June sixth 1944 without the intelligence 156 00:13:30,001 --> 00:13:35,257 from Bletchley Park. ≫> This is the, Colossus computer at Bletchley Park. Now 157 00:13:35,257 --> 00:13:40,246 we're in [inaudible] of Bletchley Park, which was the, one of the first purpose 158 00:13:40,246 --> 00:13:45,250 built computers centers and some ten of these machines were installed here, 159 00:13:45,250 --> 00:13:51,233 starting in January of 1944. Now, in the years previously a new way of encrypting 160 00:13:51,233 --> 00:13:56,492 messages was discovered and it was being used in Germany and it was all high level 161 00:13:56,492 --> 00:14:01,808 messages between Hitler and his generals. And they were encrypted on a machine 162 00:14:01,808 --> 00:14:07,094 called the Lorentz machine. And it used teleprinter traffic teleprinter codes to 163 00:14:07,094 --> 00:14:12,257 actually transmit those messages. Now, by '43, it was taking some six hours sorry, 164 00:14:12,257 --> 00:14:16,655 six weeks to actually decode those messages, and decode those messages 165 00:14:16,655 --> 00:14:22,212 laboriously by hand. The problem with that is within six weeks the usefulness of the 166 00:14:22,212 --> 00:14:27,367 intelligence that you'd gained from those messages had obviously gone. So, that 167 00:14:27,367 --> 00:14:32,467 process needed to be speeded up. Now, some techniques had been tried from, some of 168 00:14:32,467 --> 00:14:37,795 the electronic techniques had been tried here at Bletchley Park. But this machine, 169 00:14:37,795 --> 00:14:42,889 when it was put into use in early '44, reduced that six week period to decode the 170 00:14:42,889 --> 00:14:47,669 message down to six hours and that's really just a phenomenal jump. The 171 00:14:47,669 --> 00:14:53,136 machines, the messages themselves were received at various intercept stations 172 00:14:53,136 --> 00:14:59,418 around the country and were punched onto paper tape. Now, there are two paper tapes 173 00:14:59,418 --> 00:15:05,769 on the machine here at the moment, one that we are running and one which is ready 174 00:15:05,769 --> 00:15:11,324 for the next run. Now this tape, there are two here, I'll take one. Each row across 175 00:15:11,324 --> 00:15:17,112 the tape, are punched by poles, and each of those is an alphanumeric character. And 176 00:15:17,112 --> 00:15:23,240 that's the encrypted message that was received, and being punched on the tape. 177 00:15:23,240 --> 00:15:28,271 Now although Colossus has, all the elements of a modern, electronic co 178 00:15:28,271 --> 00:15:33,994 mputer, it doesn't have the memory that's, we expect in a stored program computer. 179 00:15:33,994 --> 00:15:39,934 Now what happens is that tape that message, some 5,000 characters in that 180 00:15:39,934 --> 00:15:45,680 message is actually formed in a loop and is read over here is a series of 181 00:15:45,680 --> 00:15:52,240 photoelectric sensors and lights and each character is read and 5,000 characters per 182 00:15:52,240 --> 00:15:58,109 second are read. Now each clunk of the machine you can hear there is another 183 00:15:58,109 --> 00:16:04,585 5,000 characters being read into the machine. So we are reading that same 5,000 184 00:16:04,585 --> 00:16:10,521 characters each time. This is the Control panel of the Colossus computer, so its 185 00:16:10,521 --> 00:16:15,960 this side of the machine that we are actually we runs during wartime we are 186 00:16:15,960 --> 00:16:22,253 actually using. Now I can set up the particular algorithm I want to test, and 187 00:16:22,253 --> 00:16:27,659 routines I want to test, using these control panels. And each clunk of the 188 00:16:27,659 --> 00:16:34,012 machine at the moment is another state where we're actually trying a, a new 189 00:16:34,012 --> 00:16:37,003 algorithm and repeating that algorithm on that repeating 5000 characters. The 190 00:16:37,003 --> 00:16:45,069 results that the machine detects are presented here. Now, we're doing a 191 00:16:45,069 --> 00:16:51,876 statistical analysis of that encrypted tape. Now the machine would run for some 192 00:16:51,876 --> 00:16:59,922 six hours. There are 2,500 valves in this machine. You can't see that many from the 193 00:16:59,922 --> 00:17:07,369 front, but once we go between the racks of the machines, you get an idea of the 194 00:17:07,369 --> 00:17:14,483 scale. 2,500 valves, each valve has a heater, a hot wire heater in the center of 195 00:17:14,483 --> 00:17:22,409 the valve, and operates at about 2-300 volts DC. Now five and a half 2500 valves, 196 00:17:22,409 --> 00:17:28,689 plus the power supply is generates over eight kilowatts of, uses over eight 197 00:17:28,694 --> 00:17:35,990 kilowatts of electricity. And by this point, when we're standing in between the 198 00:17:35,990 --> 00:17:43,571 racks, you can feel the heat coming off of these racks. Colossus is a combination of 199 00:17:43,571 --> 00:17:51,247 electronics, and we can see the rack, the electronics here, and these valves chassis 200 00:17:51,247 --> 00:17:58,186 members, and also electro-mechanical, switch gear. So there are banks of relay 201 00:17:58,186 --> 00:18:04,127 panels here. These big single motion detectors are a sort of motorized switch 202 00:18:04,127 --> 00:18:09,862 that will actually spin around. There's banks of those in the machine. The 203 00:18:09,862 --> 00:18:15,574 technology is equipment that was well know n for the British Post Office. This 204 00:18:15,574 --> 00:18:21,071 machine was designed by a chap called Tommy Flowers. And Tommy Flowers is an 205 00:18:21,071 --> 00:18:27,292 engineer at the, research center in London for the British post office. Tommy was 206 00:18:27,292 --> 00:18:33,171 asked to look at the problem of how to automate this task, this manual task. And 207 00:18:33,171 --> 00:18:38,101 Tommy came up with the idea of using electronics to do this. At the time, the 208 00:18:38,101 --> 00:18:42,261 idea of using more than half a dozen valves in any circuit. Which is 209 00:18:42,261 --> 00:18:47,459 [inaudible] simply poo pooed. Valves had a bad reputation. People had valves in their 210 00:18:47,459 --> 00:18:52,494 radios at home. They failed when they switched the radios on. So the idea of 211 00:18:52,494 --> 00:18:58,569 using 2500 which is simply phenomenal. But Tommy understood that it's probably, it's 212 00:18:58,569 --> 00:19:03,446 almost certainly the thermal shock that kills valves in the first place. So, if 213 00:19:03,446 --> 00:19:08,112 you leave the machine on and don't subject it to that shock, you won't have a 214 00:19:08,112 --> 00:19:13,652 problem. Now all of the ten Colloseus machines here at Bletchley Park were left 215 00:19:13,652 --> 00:19:20,336 on permanently. The machines are operated by Wrens in three shifts throughout 216 00:19:20,336 --> 00:19:26,002 the day. We, have to be seen equally careful. This is obviously, this is a 217 00:19:26,002 --> 00:19:31,048 replica of the machine, itself. But the same problems apply. We need to be, 218 00:19:31,048 --> 00:19:37,067 careful in bringing the supply voltages up gradually, so we don't suffer from thermal 219 00:19:37,067 --> 00:19:43,047 shock, and in the same way in shutting the machine down. Tommy had the idea of 220 00:19:43,047 --> 00:19:49,059 generating the key, cuz it's a key that we're comparing with that encrypted type, 221 00:19:49,059 --> 00:19:55,042 generating that key electronically, and these counters here, they're called the 222 00:19:55,042 --> 00:20:00,292 souratron rings, souratron valves, actually holds that, that count. Now we 223 00:20:00,292 --> 00:20:06,086 describe Colossus' not having a memory, we're saying not, not having a memory in 224 00:20:06,086 --> 00:20:12,375 the sense that, modern computers have a, have a memory that's common for data and 225 00:20:12,375 --> 00:20:18,357 for programs. Well, the program here. Set on those control panels at the front and 226 00:20:18,357 --> 00:20:24,211 that's switch, switch and plug programmed, much like say, its contemporary ENIAC 227 00:20:24,211 --> 00:20:29,420 machine. But these machines, these valves at the back do act as a store, in the 228 00:20:29,420 --> 00:20:35,172 sense of counters, and they're actually counting the score that we're actually 229 00:20:35,172 --> 00:20:40,970 getting. Each pass through the algorithm. We, we can see at the back here well, 230 00:20:40,970 --> 00:20:46,636 certainly some of the modern technology. I suspect the wartime guys that were 231 00:20:46,636 --> 00:20:51,610 building and debugging these machines. I've given anything for a little 232 00:20:51,610 --> 00:20:57,036 [inaudible] and let alone a logic analyzer. If I look into the machine down 233 00:20:57,036 --> 00:21:03,031 here back, you can see the projected image that's coming off the tape. And that's 234 00:21:03,031 --> 00:21:08,266 shining onto five photo sensitive valves. And it's those valves that are actually 235 00:21:08,266 --> 00:21:13,772 reeling the 5,000 characters every second. The paper tape was used well into the 236 00:21:13,772 --> 00:21:19,354 1960's and 70's. At this speed it was simply phenomenal and hadn't really been 237 00:21:19,354 --> 00:21:25,398 thought of before. And our original museum director Tony Sale wanted to rebuild the 238 00:21:25,398 --> 00:21:30,953 Colossus and build a replica that was a machine. This was some twenty years ago. 239 00:21:30,953 --> 00:21:35,334 There is very little information out there, there are a few pictures that are 240 00:21:35,334 --> 00:21:40,696 attached, possibly illegally. A few scraps of circuit diagrams, and just the memories 241 00:21:40,696 --> 00:21:45,362 of some of the original pioneers who worked on the machine. And when Tony 242 00:21:45,362 --> 00:21:49,691 started the plant, Tommy Flowers was still alive and remember he was able to draw 243 00:21:49,691 --> 00:21:53,549 circuits. [inaudible] finding the parts as well. But the important thing is the 244 00:21:53,549 --> 00:21:58,760 machine was designed by a post office engineer at the time. An engineer that was 245 00:21:58,760 --> 00:22:03,980 used to designing systems for telephone switching. So, a lot of the components 246 00:22:03,980 --> 00:22:09,866 here, everything from the relay banks, to the switches, to the power supplies, were 247 00:22:09,866 --> 00:22:15,785 common to British post offices in the pre-war period. So, when Tony then wants 248 00:22:15,785 --> 00:22:21,438 to find the components to rebuild the replica, he's lucky in the sense that the 249 00:22:21,438 --> 00:22:26,619 last of those exchanges are being decommissioned from post offices around 250 00:22:26,619 --> 00:22:31,874 the country. Tony was therefore able to really sort of back up a pickup truck. At 251 00:22:31,874 --> 00:22:36,924 the back of the exchange and take away all of those components and dismantle all 252 00:22:36,924 --> 00:22:41,665 those components. And they are, they were absolutely perfect. And it was just that 253 00:22:41,665 --> 00:22:45,930 timing. It really couldn't have been better. ≫> So, Allen Turing actually 254 00:22:45,930 --> 00:22:50,115 left Bletchley Park after about three and a half years. His involvement really 255 00:22:50,428 --> 00:22:54,786 finished. He went to the United States. Turing became, was not actually involved 256 00:22:54,786 --> 00:22:59,908 in the development of Colossus. Some of the statistical work that he did was used 257 00:22:59,908 --> 00:23:04,444 by the people. Pri-, predominately Bill [unknown], who was the guy who actually 258 00:23:04,444 --> 00:23:09,990 constructed Lorentz machine quite remarkably a remarkable feat indeed Jerry 259 00:23:09,990 --> 00:23:14,351 even got into things like speech scrambling systems and went to the United 260 00:23:14,351 --> 00:23:18,505 States and was involved in other projects so he wasn't really involved in Colossus. 261 00:23:18,660 --> 00:23:22,913 At the end of the war Jerry went to work for the National Physics Laboratory, again 262 00:23:22,913 --> 00:23:27,179 pursuing these sort of ideas and then of course he ended up in the University of 263 00:23:27,179 --> 00:23:31,707 Manchester where March Newman, who had run the department where the Colossus 264 00:23:31,707 --> 00:23:36,121 computers had been located. But Newport also ended up as the head of mathematics 265 00:23:36,121 --> 00:23:40,801 and obviously then at that point Jerry became involved in the very early computer 266 00:23:40,801 --> 00:23:46,845 developments in Britain Gordon Weitzman immigrated to the United States at the end 267 00:23:46,845 --> 00:23:51,820 of the war. In 1948 he immigrated to the United States and became involved in many 268 00:23:51,820 --> 00:23:56,510 of the early American Community Developments Project. World Wind Welchman 269 00:23:56,510 --> 00:24:01,419 worked at MIT and he taught the first course in computer science at MIT. So 270 00:24:01,419 --> 00:24:06,391 Turing then was involved with things like The Manchester Baby and the Frankie Mark 271 00:24:06,391 --> 00:24:11,029 one and the nearly computing developments I guess this is well known of course, 272 00:24:11,029 --> 00:24:50,046 Touring tragically committed suicide in 1940, 1954. [music]