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Gresham College: A history of computing in three parts

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Edited by Christopher Douce, Tuesday, 15 Oct 2019, 15:47

After a week and a half of continual exam and assignment marking, I was relieved to finally be able to turn my attention to other matters (and get out of my house).  I had an idle question: I wondered whether there were any professors or lecturers in London who shared an interest in the history of computing or technology.  Rather than trawling through university web pages (which was the first idea that crossed my mind), I decided to ask the internet, searching for the words, ‘history computing lecturer London’.

One name was clearly at the top of the list, but it was something else a bit lower down the search result that immediately attracted my attention.  It was a series of lectures entitled, ‘a history of computing in three parts’.  My first reactions were, ‘it’s probably too late’ and, ‘you’ve probably got to pay a lot of money to go along to this gig’.  All this computer history stuff that I’m interested in has to be folded into my day job which means that that it’s easier to justify time but a whole lot harder to justify expenses.

After reading the paragraph that described the event, I cast my eye back to the heading.  I realised that the date of the lecture was TODAY!  The very same day I had done my Google search, Thursday 31 October!  After a few more clicks I discovered that the event was also FREE!  Behold, it was a miracle!  I looked at my calendar; the lecture started at four in the afternoon and provided that I managed to sort out some admin stuff and have a meeting with a colleague, I would probably have enough time.

The only fly in the ointment was that it was all booked up; there were no tickets remaining.  Who knew that the history of computers was such a popular subject?  No matter.  I was looking reasonably smart – I would try to talk my way in.

Lecture 1: Pictures of computers

After a few false starts I managed to find my way to a place called Gresham College (website); navigating my way out of Chancery Lane tube proved to be quite tricky. It is only in retrospect that I realised that this was one of those places in London that I really ought to have known about.  I just know that people who I speak to about this event will chuckle, slap their thigh and say, ‘oh yes, Gresham College...’ and then will look at me as if I’m some kind of idiot if I said that I had visited there ‘by accident’.

I strode purposefully down a long alleyway and was confronted by a smartly dressed gentleman who obviously had an important role to play.  I began my attack: ‘I’m, erm, here for the lecture…’, and was swiftly gestured towards a flight of stairs without a word.   I felt deflated!  I was expecting to fight my way into the lecture!  I soon found myself in an anti-chamber filled with men (and women) in anoraks looking at a projector screen and noisily settled down to what was the first lecture by Martin Campbell-Kelly.

I joined the lecture at the point where people were being shown coloured photos of office equipment and pictures of steel filing cabinets.  The context was that computers are machines that allow us to process ever increasing amounts of data (and there’s a whole history of manual record keeping that we can easily overlook).  We were then told something about the history of the Rand Corporation followed by parts of the history of the computer company IBM.

On the subject of IBM, he mentioned someone called Eliot Noyes (Wikipedia).  Noyes was for IBM as Jonathan Ive (Wikipedia) is for Apple (if you’re into industrial design).  Martin mentioned that mainframe computers had a particular look; for a time there was a particular ‘design zeitgeist’.  I’ve made notes that Noyes used to look over catalogues from the Italian company Olivetti, and not only designed computers, but entire rooms.  We were shown photographs of various mock-ups. 

The creation of physical prototypes reminded me of some themes that are mentioned in a couple of design modules, either Design Essentials or Design for Engineers.  Martin also made reference to designer Norman Bel Geddes (Wikipedia).  He also showed us a whole host of other pictures of big machines, notably the ICL 2900 (Wikipedia) used in the Bankers’ Automated Clearing System (BACS).  (I have to confess being dragged into the depth of the Wikipedia page about that particular ICL computer.  Should I confess to such level of geekiness?  Probably not!)

Martin’s talk wasn’t really what I had expected but I found it pretty interesting (and it was a shame I missed the first quarter of it).  I was surprised by the detail that he provided about manual filing systems but I was also encouraged by the inclusion of information about designers.  The visual and industrial design aspect is an important part of computing history too.  Thinking back, one of my first computers had a very different aesthetic to the machines that I use today.  Function and fashion, combined with the wider perception of devices and machines are perspectives that are inexplicably linked.

After the lecture, it later dawned on me that I’ve actually read one of Martin’s books, ‘Computer: a history of the information machine’ which he co-authored with William Aspray.  It’s a pretty good read.  It covers a range of different strands; the pre-history, early electronic machines (such as the UNIVAC, which he touched on in his talk), before moving onto the emergence of the internet and software.  It’s tough to do everything but he has a good old go at it.

Lecture 2: Turing and his work

The second lecture of the day was by Professor Jonathan Bowen (website).  Jonathan talked about the life and work of Alan Turing (Wikipedia) and mentioned Alan Hodges’s scholarly biography, ‘the enigma of intelligence’. 

Jonathan spoke about three key areas of Turing’s work: his work that relates to the fundamentals of computer science, philosophical work relating to artificial intelligence and his later work on morphogenesis (which now has strong connections to the field of bioinformatics).  He mentioned his birth place, spoke about his PhD research which took place at Princeton University (with Alonzo Church being his doctoral supervisor), and also spoke about his work at Bletchley Park.  Other aspects of his life were touched on, such as his work in the National Physical Laboratory (NLP) in Teddington and his movement to the University of Manchester.  During his time in the NPL, he worked on the design of a computer which then became the Pilot Ace (Wikipedia).  When he was at Manchester, he was familiar with the Manchester Mark I computer (the world’s first stored program computer, and don’t let any American tell you otherwise).

What I liked about Jonathan’s talk was its breadth.  He covered many different aspects of Turing life in a very short space of time.  He also spoke of the ambiguity regarding his death, echoing what Hodges had written in his biography of Turing

At the end of his talk, we were directed to a set of web links that might be of interest to some.  Last year was the centenary of Turing’s birth, and there is a commemorative website that contains a whole host of different resources to celebrate this.  There is also a site that is maintained by his biographer, Alan Hodges (turing.org.uk).  Interestingly, we were also directed to an on-line archive of documents which can be accessed by computer scientists, historians or anyone else who might be interested.

Lecture 3: The grand narrative of the history of computing

The headline act of the night was Doron Swade.  I know of Doron’s work from the Science Museum where he headed up a project to construct a working version of Charles Babbage’s design for his Difference Engine number 2.  Babbage (for those who don’t know of him) is a Victorian inventor and raconteur whose lifelong quest was to build and design mechanical calculating machines.  During his life, he had a battle with his engineer, had the challenge of securing money for his ideas, travelled around Italy and hosted some famous parties (and did a whole lot more).

The title of Doran’s lecture was an intriguing and demanding one.  Could there really be a grand narrative about the history of computing?  If so, what elements or ingredients might it contain?  Doron told us that the history of computing is an emerging field and then posed a similar question: ‘what strings [the different] pieces together?’  He also reassured us that there was a clear narrative that appears to be emerging.

The narrative begins with methods for accounting and number systems, i.e. mechanisms to keep track of number.  We could consider the pre-history to comprise of artefacts such as tally sticks or physical devices that can be used to ‘relieve or replace mental calculation’.  This led to the emergence of mechanisms that used moving parts, such as an abacus and a slide rule.  The next ‘chapter’ would comprise of devices that embodied algorithms; their mechanisms carried out sequences or steps of calculations.  Here we have the work of Babbage and links to Hollerith (who was mentioned by Campbell-Kelly).

Doron then presented us with a challenge.  If we represent history in this way there is an implicit suggestion that there is a clear deterministic path from the past through to the present.  If I understand the point correctly, any narrative (or description of the past) is always going to be flawed, since there is so much more going on.  There could be situations in which nothing much happens.  A really interesting thought that Doron introduced was the idea of a ‘stored program’ being met with puzzlement and confusion, but this is an idea that distinctly defines what a computer is today.  (I haven’t made a word for word note of what Doron said, but this is something that has certainly stuck in my mind).

Another interesting point is that a serial narrative naturally excludes the parallel.  There is also an issue of reflexivity (to nick a posh word that I learnt from the social sciences); there is a relationship between history making machines and machines making history.  Linearity, it is argued, does a disservice.  One way to get over the challenge of linearity is to draw upon the stories of people.  These thoughts reminded me of a talk by Tilly Blyth, current keeper of technologies at the science museum, about the forthcoming ‘information age’ gallery.  Tilly also emphasised the importance of personal narratives and also cautioned about viewing history as a deterministic process.

One of the highlights of Doran’s talk was his ‘river diagram’ of the ‘history of computing’ (my ‘quotes’ at this point, since I don’t think I made a note of a ‘heading’).  Obviously, a picture is much better, but I’ll have a go at describing it succinctly. 

In essence, the grand narrative comprises of a bunch of different threads.  One thread that runs through it all is the history of calculation.  There is another thread about the history of communication.  In the middle, these threads are linked by ‘tributaries’ which relate to the subjects of automatic computation and information management.  These lead to another (current) thread of study which is entitled ‘electronic information age’.  I also made a note of a fabulous turn of phrase.  The current electronic information age emerged from the ‘fusion chamber of solid state physics’. Another bit of the diagram relates to different ways in which calculation or computation could be realised: mechanical, electromechanical or electronic. 

I also made a quick note of what were considered to be the core ideas in computing: mechanical processes, digital logic, algorithms, systems architecture, software and universality (I’m not sure what this means, though) and the internal stored program.  A narrative, it was argued, comes from a splicing together of different threads.

Returning to Babbage, Doran said that ‘[he] burst out of nowhere and confounds us with schemes that are unprecedented’; proposing mechanical calculating machines the size of rooms.  Doran also spoke about Ada Lovelace’s description of Babbage’s designs of his Analytical Engine, a machine that embodies many of the core ideas that are used in computing today: ‘a fetch execute cycle, transfer of memory form the processor, programmable, automatic execution, separation of program and memory’.

Doran ends with a question: ‘to what extent did this [Babbage’s work] influence modern computing?’  The answer is, ‘probably, not very much…’ (my quotes this time, rather than Doran’s), since many of Babbage’s discoveries and inventions were rediscovered and re-implemented as computing devices were realised in different forms, moving from the mechanical to the electrical.  Doran argued that perhaps because there is so much congruence between the different approaches, the ideas that have been rediscovered and re-implemented may well be really important and fundamental to the subject of computation.  To paraphrase from Doran’s book, Babbage isn’t so much a ‘great grandfather’ of computing, more of a ‘great uncle’.

Reflections

For me, Doron’s talk tied together aspects of the earlier talks.  Martin spoke about the history of information management and touched upon the electromechanical world of computing.  By describing the work of Turing, Jonathan spoke about and connected to the history of automatic computation.  One of the challenges that I’ve been grappling with is that there is so much history that is fundamentally interesting.  I’m interested in learning more, but it remains difficult to know which parts of a bigger picture to focus on. 

What I personally got from the day was a confirmation that my interest in related subjects such as communication technologies and the use, development and deployment of software (and algorithms) do indeed form an important piece of a ‘grand narrative’ in the history of computing and information technology.  Whilst I instinctively knew this to be true, Doran’s river diagram, for me, drew together different influences and connections in a very clear and obvious way.

Before heading home, I grabbed a brochure that had the title, ‘free public lectures’, vowing that I would have a good look  though it to see what else was going on.  After saying a few goodbyes to people I left the basement room and walked up a flight of stairs.  In the intervening hours, it had become dark; time had passed and I hadn’t really noticed.  When I reached the street I reached into by inside pocket for my smartphone to see if I had any messages.  A light was flashing.  I didn’t have any messages but I had a few alerts.  A theoretical Turing machine rendered into a physical device was alerting me to a comedy night that was to take place later on that week.  This was also a gentle reminder about how subtly technology had become entwined with my life.  Was I reliant on this little device?  That was a whole other question.

When I was heading home I asked myself, ‘how come I never knew this Gresham college place existed?’  Perhaps it is only one of those places that you hear about if you’re ‘in the know’.  London, for me, is gradually revealing some of its secrets.

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Breaking Enigma and the legacy of Alan Turing in Code Breaking, City University, London

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Edited by Christopher Douce, Friday, 18 May 2018, 09:08

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As soon as I received an email advertising a public lecture at City University by Processor David Stupples on 17 April about the life and legacy of Alan Turing, a couple of weeks after finishing reading Alan Hodge's biography, I knew I had to make the time to come along.  This blog is a summary of some aspects of the event, accompanied by a set of thoughts that the lecture inspired.  I should add that I'm neither a mathematician and nor a cryptographer, but the story of code breaking and the history of Bletchley Park (and how it came to be) is one that has and continues to fascinate me.

David Stupples is professor of systems and cryptography at City University.  His lecture is one of a series of lectures that are given at City, but this one coincides with the centenary of Alan's birth.  The lecture also celebrates the creation of the City University Centre for Cybersecurity Sciences (City University website).

David's lecture began at the end, beginning briefly with Alan Turing's death in 1954, before moving onto a number of subjects which relate to cryptography, the breaking of the enigma code, stories about daring plots to capture code books and then concluding by speaking briefly about Alan Turing's legacy.

Before I attempt to summarise (to the best of my abilities) some of the points that David spoke about during his lecture, he also mentioned an interesting connection between City University and the centre of wartime code breaking at Bletchley Park (website).  David mentioned a former faculty member, Arnold Lynch.  Apparently Arnold worked with electrical engineer Tommy Flowers (Wikipedia), helping to design a fast input device to the Colossus machines that were designed with help from the post office research station (Wikipedia) at Dollis Hill, London.  The work centred on the reading of paper tape loops using light as opposed to mechanics.  Colossus, Bletchley Park and Turing are intrinsically linked, but as far as I understand they are different stories.  They are linked through cryptography, which is a subject that David introduces.

Cryptography

What is cryptography?  In essence, it is study that is concerned with the hiding and writing of secret messages.  David began by introducing us all to the Caesar cipher (Wikipedia), a simple 'monoalphabetic substitution cipher'.  Simply put, you take one letter and replace it with another.  Such ciphers are easy to crack because you can eventually figure out which letter is which by looking at the structure of messages and also the frequency of individual letters.

A more sophisticated approach is to encode groups of letters (bigrams or trigrams) as a single code.  This method, we were told, dates back to Napoleonic times.  We were then introduced to the beginnings of the theory of Enigma codes through the Vigenère cipher (Wikipedia), which I had never heard of before.

David added an interesting aside, saying that this cipher was attacked by Lord Byron's daughter, Ada, Countess of Lovelace.  Ada is also known for her work with the Victorian computing pioneer, Charles Babbage, who proposed, designed and partially built different computing engines: the analytical engine and the difference engine.

Returning to the subject in hand, one approach to encrypt a message is to use a book of codes.  A character (or group of characters) are matched with an entry in a code book, which then have a precise meaning.  Using the technical phrases: there is ciphertext (the message that you can't read), and then the plaintext (the message that you can).

One of the biggest challenges is getting these code books to the people who need to read the messages, and this is one of the biggest challenges that need to be overcome.  David hinted at the mysterious but practical notion of asymmetric keys  (Wikipedia), mentioning their application of number theory.

The Enigma and Codebreaking

One of the most interesting parts of David's talk was his description of the different types of Enigma machine that were deployed; different parts of the German military used different variants.  An Enigma machine comprises of plug boards (which I understand to be a character substitution mechanism) along with a number of rotors, and a reflector which passes a signal back through each of the rotors.  These elements, in combination with each other, create cryptographic combinations in numbers that are quite literally astronomical and unimaginable.  Different machines would have slightly different configurations and different numbers of rotors.  The greater the numbers of rotors, the more 'secure' the code.

Another added complexity was that Enigma operators can also use code books.  Code books in combination with plug boards in combination with rotors which have all been used to encrypt messages in another language presents a problem that feel as if it should be impossible to solve.

So, how was it possible to break the Enigma, to recover plain text from cipher text? I have to confess when it came to following some of the detail, I became a little lost.  Understanding codes and ciphers, how they work and their weaknesses requires the application of an energetic amount of mental gymnastics.  Knowing the background and context behind the discoveries is a useful prerequisite to understanding the detail.

The first aspect lies with some work carried out by Polish cryptographers, whose work was invaluable (Bletchley Park has a permanent exhibit which acknowledges their essential contribution).  There was also, apparently, a spy involved, who managed to gather some essential intelligence (which was another part of the story I had not heard of).

The second aspect, the Polish cryptographers also worked on devices that helped to apply brute force to the decrypting of messages.  They created something called a Bombe (Wikipedia).  Their work inspired a new generation of devices (a reconstruction of which can be seen at Bletchley Park).

The third aspect (and there probably are more than just three aspects, of course) is the occurrence of human error.  Enigma operators would make mistakes (as would operators of TUNNY, too), which would convey clues as to how the machines operated and were configured.

Context

Towards the end of the talk, David connected work that was carried out in the second world war to the time of the cold war.  This was the first time I had heard anyone speak about this subject and the connections.  The audience were shown photographs of KL47 and KL7 devices (Wikipedia) that could be considered to be the successors of Enigma.  We were then treated to some spy stories, which reminded us all that keeping (and uncovering) secrets is as much a human challenge as it is a technical one.

Cryptography isn't a subject that is only applicable to the military (although I clearly sense that the military and military intelligence has been the main driver).  It isn't only about keeping secrets safe from spies.  Whenever you buy something over the internet, when the padlock symbol lights up on your internet browser, you make use of asymmetric keys.  (Incidentally, this mechanism was independently discovered by two different groups, but this is totally different story).  

Also, whenever you make a call on a digital mobile phone, encryption comes into play.  David mentioned the situation where cryptography is used from the point when you request money from a cash machine, and the resulting information about transaction is transmitted onwards to other banking machinery.

A really interesting point that I took a note of is that there is a constant battle between cryptographers (those wishing to keep secrets) and cryptanalysts (those who are wishing to break into codes and extract secrets).  This is a battle that is going to run and run, with both mathematics and computing being central tools for both sides.

Reflections

The biographies and Turing, the history of Bletchley Park, and the development of some of the most fundamental ideas within computer science are all intrinsically connected.  With any lecture on the subject, there is a difficult decision to make about what to focus on, what to touch upon and what to leave out.  It was great to hear of references to Turing's theory of computability and his connection with the ACE computer at the National Physical Laboratory, as well as his link to the development of the world's first stored-program computer at the University of Manchester.

The history of the code breaking and learning about the social, political and technological environment in which it took place is fascinating.  One thought that I did have was that perhaps Turing, as a man, might have featured more.  But, as mentioned, it's tough to separate out the different elements of a broader complex story.  Code breaking, Turing and computing are all connected.

All in all, a lively and informative talk that presented, for me, a new angle on some very interesting aspects of the code breaking story.  

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