# Programming bio

WARNING: This is nearly 6000 words, and mostly written for my own amusement and reminiscence-enablement. Some of it is funny, though not all that much, and not all that funny. Read at own risk.

## The early days (1982-1992)

#### School

The first computer I ever saw was a Sinclair ZX81 belonging to a neighbour. I remember writing Pacman-like games in BASIC in a little notebook during breaks at school. I don’t think I ever even typed most of them into a real computer! The first computer I owned was a Sinclair ZX Spectrum, which was the big thing in the UK at the time. BASIC again, though I did learn Z80 assembler using it, and had a first play with C using a compiler from a company called HiSOFT. After a bit, I moved on to an Amstrad CPC machine, running CP/M. I wrote some little adventure games in Z80 assembler, using CP/M’s nice relocating macro assembler.

#### Sixth form

It wasn’t until sixth form college that I got access to something more substantial. There was an old Honeywell “super-micro” the size of a washing machine1 that had been “acquired” by the head of computer science, along with four terminals, a proper mainframe-style dot-matrix printer and a six foot high pile of documentation. No-one really knew what to do with it, so I got it going and had my first joyous experience of system administration. This thing ran an operating system called GCOS, which was heavily influenced by Multics and was pretty cool. The only distressing feature from a systems admin point of view was that it was so secure that it was possible to put files into a state where no-one could read them and no-one could delete them, not even the system administrator2. I only did that once…

We had a Pascal compiler for this beast and a friend of mine implemented a simple Lisp interpreter using it for his A-Level computing project. I helped, making sure the washing machine kept the whites white and the colours bright.

Meanwhile, my own A-Level project was a bit more gritty and industrial. The chemistry department had “acquired” (lots of acquiring going on!) an infra-red photometer from a local company that no longer needed it, and one of the chemistry teachers wanted to use it in class, to try to show some more modern analytical techniques to the students than “What colour is it? What does it smell like? No, Jenkins, just a little sniff! You’re not huffing paint!”. Unfortunately, this thing recorded traces of spectra on paper rolls that were expensive and hard to get. The photometer had two intriguing little wires coming out of it though, providing an analogue representation of the transmissivity of the sample at different wavelengths, along with some timing information. At this time, the most common computer in British schools was the BBC Micro. The designers of this thing had the genius idea of including an analogue-to-digital converter as part of the standard build. Combined with the very clever assembler built into the BBC BASIC interpreter, this made a platform that was ideal for all sorts of laboratory applications. So, adventures in 6502 assembler followed, as I wrote an application to collect, display and archive infra-red spectra. This was a really fun little project, involving lots of cycle-counting to get sampling rates just right. I don’t know how much use this thing saw in practice, but it kept me entertained for a couple of weeks.

After sixth form, there was a bit of a programming gap, since my physics undergraduate degree involved only a little bit of programming (in Pascal, of all things, although this time on Unix).

## Coding for cash (1992-1997)

At the end of my physics degree, I knew I wanted to do some sort of research, but didn’t have a clue what. So, I thought I’d go out and get a job for a year or two before coming back for a PhD. Good plan, very poorly executed. I was pretty strapped for cash at the time, and quickly landed a job with a little company just outside Oxford that wrote software for editing dictionaries. Perhaps not the most exciting application domain ever, but they were prepared to pay me real actual money for writing code, mostly in C. (They also had some SNOBOL code in house, though I never touched that.) I didn’t last long there, since I didn’t feel like I was learning all that much3, and I applied for a job at a company in London writing software for a dealing room data distribution system for banks.

#### IISC: London & Paris

My abiding memory of the interview there was walking out afterwards and having Duncan, who would be a long-term colleague, tell me “Ask them for more money!”. So I did, and I got the job. I spent a year and a bit at IISC (Investment Intelligence Systems Corporation), first working on a news quality monitoring system for Reuters, which was a thing written in Borland C++ that was supposed to sit in Reuters data centres and collect timing information about the propagation of news stories through their network, sending information over an X.25 link to a VAX somewhere, where statistics would be calculated. This was pretty much pre-internet, so the Reuters newsfeeds came in over phone lines as RS-232 or something equally entertaining. I spent many happy hours swearing at an RS-232 protocol analyser in the dusty cupboard in our offices where the Reuters line came into our building.

The Reuters thing was just a sideline though. The main product we worked on was a dealing room data distribution system. This was a distributed system (a big deal back then) that took data from multiple stock market or data supplier feeds, multiplexed it and made it available to traders at their desks. This stuff was all running on IBM RS/6000 machines, using IBM’s almost-Unix-but-not-quite, AIX4. The core code was mostly written in C, with some APL5, but I did some “experimental” work to try to build an SNMP agent for our system in C++. The AIX C++ compiler at the time was “immature”, at best, which meant that effort stalled pretty quickly.

One of the main clients for our system was Banque Nationale de Paris, and the boss of our company decided it would be good to have some people on the ground in Paris. Duncan and me, his trusty sidekick, were duly dispatched to the lion’s den of the main BNP test centre in Paris, where we lived for about nine months, with the constant promise of our own office and occasional fly-by booze-up visits from head office to keep us sweet. This was my first experience of working at a client site, and it was dire. The BNP people didn’t trust us, the dealers and the bank bigwigs were in an office just round the corner and prone to fly off the handle at any software failure, and for sure, we got the fall-out. We pulled a lot of all-nighters trying to get things working, and we had a couple of inglorious moments: debugging the latest install at 3 a.m. in the basement of the main BNP dealing room while our main BNP contact wrung his hands watching us shouting at each other; causing a full-scale crash of the whole BNP dealing room when we pushed a release with a seemingly innocuous change made by someone in London (which made all instances of our Curses-based front-end display all text in black letters on a black background…).

Two events stick out in my mind. The first was a bit of silly pissing around when the head of development was over from London. After a “heavy” lunch, we were all sitting there, I was doing some system admin clean-up on one machine and the others were sitting next to me, kibitzing. In a root shell, I typed “/bin/rm -fr *”, and the wine from lunch made me fail to notice I was in the root directory of the machine. “No! NO! Shit, shit, shit, NOOOO!”. By the time my frantic mashing of the keyboard had stopped the wholesale deletion that was going on, I had essentially bricked the machine. Still, that’s what OS install tapes are for. (Oh, those were the days.) The install was going fine, just chugging along, but I was watching it carefully. I’d already screwed up once, and I didn’t fancy anything else going wrong. But then weird messages started appearing on the console. I can’t remember exactly what they said, but they started as “slightly anomalous” and quickly moved into “what the hell?!” territory. Duncan and Phil were working away at the next machine, and I didn’t want to disturb them, but I was getting antsier and antsier about this and muttering quietly to myself. The two others eventually broke down into fits of giggles. Apparently, AIX activated its network connection at some point during the OS install, allowing Phil to log in over the network and start piping silly messages to the system console. Bastard. The big bang and the howling over the phone from London when Phil spilled his coffee into the power supply of his desktop RS/6000 sort of made up for it a little while later though.

The second incident was a bit more “serious”, or at least work-oriented. One of the stock market feeds we had to deal was a French feed called TOPVAL, which carried price information for all the stocks on the main French exchange, including those used to form the CAC40 index. BNP, being the Banque Nationale de Paris, was supposed to be one of the main market makers for these stocks. Unfortunately, the TOPVAL feeds were more or less unmitigated crap, falling over completely a couple of times a day. The main dealing room had a couple of separate feeds going in, but our feed handlers were not properly fault-tolerant, so there wasn’t any real mechanism to recover from failure of one feed. Our eternal nemesis at the BNP test centre was a guy called Didier, who smirked his way over to us at least once a day with some new problem, smiling that he had broken our code once again. He was a nice guy, but he definitely enjoyed his job a little too much. This TOPVAL thing had got to the point where people at IISC in London and near the top in BNP were starting to hear about it, which meant we really need to fix it. So I was tasked with making it all nice again. I invented a fault-tolerant recovery protocol so that, no matter what happened with the feeds going up and down or delivering values in a weird order, the feed handlers would be able to agree on a consistent view of the world between themselves and communicate values so that a failed feed could recover from a working feed. This took a bit of thinking, and was basically an ad hoc solution I pulled out of the air, but I got it working and handed it over to Didier for testing. All was quiet for three or four days, until Didier came to see me, looking quite glum. “I cannot break it. I have tried and tried. But I think it is perfect.” Result! No more TOPVAL-related whining.

The full-time residence at BNP wore both Duncan and me out, and the boss’s eternal reassurances that he was “really close” to securing a deal on an office for us didn’t seem to be going anywhere. We both bailed out of IISC and left Paris, to move to a company called Teknekron in London (now called TIBCO, I think).

#### Teknekron

Life at Teknekron was a lot lower-key than at IISC, even though there was some on-site work. That was mostly back-office stuff and in a relatively early stage of development, so there was no-one to shout at us, and lots of meetings. I also worked on a distributed transaction processing infrastructure, which was supposed to be something like what RabbitMQ or ZeroMQ are now. I remember writing a large Motif-based X application for administering the infrastructure: painful. Most of the work was in C++, but I also did a bit of Lisp programming, using a proprietary dialect, and I had my first exposure to Haskell, reading the language report while I was supposed to be thinking about other things, and wondering how it was actually possible to compile this amazing-sounding language into something executable.

My tenure at Teknekron lasted a little less than a year, and was brought to an end when me and my girlfriend at the time had the great idea of moving to Japan, where she would teach English in a school and I would do, well, whatever. The Teknekron people were positive about being able to find me a place in their Tokyo office, but the salaries they were talking about didn’t sound very realistic for living in a place as expensive as Japan. Fortunately, one of the people in our development team had a girlfriend who was a recruitment consultant in the City. I asked her if she thought she’d be able to find me a job in Japan. A week later, I made my way to Canary Wharf for an interview in the Credit Suisse building, and not too long after that, we were getting on a plane to Japan.

#### CSFP & UBS: Tokyo & New York

The job in Japan (at Credit Suisse Financial Products, which was Credit Suisse’s derivatives trading wing) was a front-line dealing room support position, which meant a lot of system admin, a lot of hacking at Lotus 1-2-3 spreadsheets, which was what all the traders used for their pricing calculations, and a lot of being shouted at by irate traders when things went wrong. I don’t think I fitted in there very well: I nearly got fired for trying to arrange a transfer to the “Product Development” team (the quants), I got in trouble for developing and deploying stuff6 to help the traders in Tokyo without consulting with London, etc., etc. From a tech point of view, my work was pretty dull (hence the dedicated attempts to get in trouble). I spent Christmas Day 1995 in the dealing room with two guys from London upgrading all of the traders’ desktop Sun machines. There were about 200 of them, all of which needed memory upgrades. We went out and got quite drunk when we were done.

Working at CSFP was pretty stressful and I decided to move on shortly after the “No, you can’t move departments!” incident (which, in retrospect, I could have handled much better). Duncan (from IISC) was leading a team at UBS in New York to develop a new fixed-income analytics library, and he was good enough to give me a job. That involved C++ and SQL for the main part of the job.

## Science! (1997-2001)

#### Part III Maths: Cambridge

After a working break of five years (four more than I was planning!), I returned to academia in October 1997, to do Part III Maths at Cambridge. I had all these great plans to do a PhD in particle physics theory and had spent all summer reading to get myself back up to speed before going to Cambridge. The Part III course is pretty intense, with a real “sink or swim” attitude, and I didn’t have much time for recreational programming. I did finally learn how to use LaTeX properly, using it to typeset notes for a couple of courses with some fairly complicated requirements (lots of Feynman diagrams in the quantum field theory…).

#### PhD attempt #1: Oxford

My plans changed a bit once I got some idea of the sort of work I might be doing as a particle theory PhD student in Cambridge, and I got a place in Oxford instead, in Atmospheric, Oceanic and Planetary Physics (AOPP). This was proper scientific programming. Lots of Fortran, including a line-by-line radiative transfer code whose main loop was so complicated (for efficiency reasons) that everyone was too scared to touch it, even the people who originally wrote it. I spent the first year of my time at AOPP working on retrieval code for a radiometer of an unusual design that was on its way to Mars. We hoped to be able to measure water vapour in the atmosphere, among other things. There was an existing “production” retrieval code written by some people at JPL, but it was relatively limited in application and used a retrieval method that the Oxford people didn’t like very much. So I set out to implement a new retrieval algorithm in C++. This was all going pretty well until September 1999, when the Mars Climate Orbiter carrying our instrument was supposed to enter orbit around Mars. Instead, it crashed into the surface. And yes, this was the “metric mixup” one, although there were cultural and communication issues in one of the spacecraft contractors that were probably the ultimate cause of the failure.

A sensible person would have stuck with the project I was working on, generated some synthetic data using a forward model of the instrument and results from the Mars general circulation model that was being developed at AOPP at the time, finished the retrieval code, written my PhD thesis and been done and doctored in the allotted time. Not being a sensible person, and being surrounded by glum people, all a bit annoyed at losing this instrument for the second time (an earlier version of the thing had been on another orbiter that was lost), I took a rather silly decision, to switch projects, switch supervisors, and to do something I had no experience for, which was to try to develop hardware and associated electronics and software for a prototype optical delay line for a space mission to detect gravitational waves using laser interferometry. I spent two years learning all sorts of things about metalworking and workshop work, electronics design, including some FPGA stuff, did a bit of optical design (using Mathematica), learnt about Forth, optical heterodyning and precision interferometric measurement, DSP assembler programming, and sundry other things. At the end of two years, I was much more knowledgeable than before, but had nothing to show for it in terms of material to turn into a PhD thesis.

## Back in the world (2001-2004)

After the emotional trauma of disengaging from my failed PhD attempt, I needed to find a job quickly (one of the main reasons for leaving AOPP was lack of funds). I got a job with a small software company in Oxford, developing software for managing architectural drawings for building companies, in C++. I was mostly hired for my networking experience, and was told I would be in the middle of the range of experience of the team. It turned out I was the only person in the team with any real networking experience, and that the code base that they had was really pretty bad (including a bad C++ implementation of something that looked very much like a broken version of the TCP congestion control mechanism, which they then layered on top of a regular TCP socket connection…). It became pretty clear pretty quickly that this company was going to fail and I ended up doing “people work” during the wind-up process, which I didn’t enjoy at all. I did learn one lesson there though, which is to be much more careful about understanding the position you’ll be going into when you join a new company – are the people involved really as good as they think? do they really have the necessary experience (or raw intelligence) to do what they’re trying to do? If you can’t be sure about those things, you can end up in a world of pain.

My next, less disastrous, gig was with an aerospace company in Somerset, who hired me because of my work in Oxford and my programming background. These people were a much more professional outfit. I did a bit of C++ programming here, a bit of Matlab and Mathematica stuff, but spent most of my time working on performance calculations for a naval sonar system (“aerospace”, they said, but submarines orbit the planet a bit slower than most satellites, I think). This wasn’t really what I was hired to do, and I was less than keen about working on defence stuff7. I did learn quite a bit about ocean acoustics, and wrote a long report recommending the way forward for development of synthetic acoustic environments for testing sonar system designs, which would have been fun to develop. I don’t know if that ever went anywhere – I left, both because of the defence issue, and for personal reasons.

After SEA, I spent a few months living in Aberystwyth, where I did some teaching, some AutoLISP coding for a local renewable energy company (a little parameterisable wind turbine model for doing visibility and impact assessments in AutoCAD), and tried to sell the local arts centre on the idea of letting me redo their website and booking system using a Scheme web-compositing system I was developing. The arts centre didn’t bite, but they paid me a bit of money (for my chutzpah, I think).

Eventually, a better opportunity came along in the form of a startup being led by an old school friend (he of the Lisp interpreter A-Level project). I think I was employee number three here. The idea was to build new, more language-aware, development tools. This started out as being mostly language-agnostic, but ended up, for reasons of familiarity and tractability mostly being about Java. I wrote some interesting things in Scheme as well though, in particular some code for persistent representation of syntax trees. I wish I’d kept at that, since those kinds of ideas are at the basis of the persistent data structures now used in Haskell and Clojure (and starting to be used in other places too). I also did a bit of Haskell stuff here, mostly for small experiments.

We managed to get some angel investor funding, hired some more people (including Julian, someone I’d worked with in Oxford before), and we seemed to be pretty set. There were a lot of good ideas floating around and we had quite a buzz going about the project. Things didn’t really pan out though. I don’t know if it was because we were initially too ambitious, or that we just all had different ideas about the ultimate goal, so were all pulling in different directions, but in the end, things dissolved a little unpleasantly, and there were bad feelings all round. It was a real shame, as there really was something there.

After that, I did a bit of contracting work for a company producing specialised FPGA-like hardware and the associated synthesis and place-and-route software (written in C++). My work here was mostly an attempt to bring a more scientific and systematic approach to the assessment of the performance of the place-and-route tools, which used a simulated annealing method to find good solutions. The hardware was quite heterogeneous, with a lot of specialised units, which made the place-and-route tricky and quite variable in its performance. I did a bunch of experiments to try to come up with some systematic performance measurements for the software. It was pretty interesting, and something quite new for me.

## Academia again (2004-2012)

#### Research Assistant: Bristol

About this time, my new girlfriend Rita (who had just started a PhD) told me about a possible research job in a group associated with the one she worked in. I applied, got the job, and so moved back into academia.

This was another new thing for me, since the job involved running paleoclimate simulations with a large atmosphere-ocean general circulation model coupled to a dynamic vegetation model. The GCM was in a mixture of Fortran and C++, using MPI for parallelisation on a Linux cluster, and the vegetation model was LPJ, something I went on to use a lot. There was some fun and games getting this thing working on our cluster, since the model had quite a few bugs that only popped up with some Fortran compilers and some initial conditions. I got to hate this one error message, where the semi-Lagrangian transport scheme for water vapour in the atmosphere model detected wind speeds that were unrealistic and so stopped. After a long time spent tracing this down, it turned out to have nothing to do with the semi-Lagrangian transport, nothing to do with the winds, nothing to do with the atmosphere at all, but was due to NaNs being produced under certain conditions in the code in the vegetation model that calculated surface evaporation. These NaNs propagated into the atmosphere model and buggered everything up. All in all, it was a pretty delicate piece of software, and took a lot of massaging to get it working satisfactorily.

As well as the main work on the GCM simulations, I also wrote some Fortran 95 post-processing code to take results from the model (and another model being used by someone else in the group) and transform them into the archival format required by the EU project we were working on. This turned out to be fairly non-trivial!

I also did a lot of Perl scripting, for preparing initial and boundary conditions for the model, and a lot of NCL scripting for plotting results (including a C++ program driving NCL to plot hundreds of plots for different models from the project database for a benchmarking exercise).

#### PhD attempt #2: Bristol

As the Research Assistant contract I was on was coming to an end, it seemed like the natural thing to do would be to apply for a PhD place. I was ready for another go, having almost forgotten the trauma of my AOPP days. So, I wrote a proposal for some funding, applied for a PhD place, got in, and spent the next three years doing a whole bunch of new and even weirder stuff.

To start with, my main goal was to try to apply some methods from dynamical systems theory to the analysis of climate models. There had been a whole series of papers on this stuff for ocean models, from Henk Dijkstra’s group in Holland, and I was thinking about how I might apply some of this stuff to atmosphere models. This turned out not to be practical, mostly because of the absence of good distinguished low-dimensional states in atmosphere models to start a numerical continuation from, but I learnt a lot trying to do this. My two supervisors (Paul Valdes, the head of our climate modelling group in the Bristol geography department, and Steve Wiggins, at that time head of the maths department) mostly let me get on with it, working on the basis that I was doing something, and it might end up going somewhere interesting.

I spent a lot of time writing C++ code to do numerical continuation of solutions to computer models of dynamical systems, using some of the libraries from Sandia’s Trilinos project. Along the way, I also did a fair bit of Mathematica stuff for experimentation, mostly driven by things Steve pointed me at. I also continued with some vegetation modelling work using the LPJ model, did lots of data visualisation using NCL and POV-Ray, and set up and administered a wiki for our research group, which involved a bit of PHP hacking.

After I realised that my atmospheric model numerical continuation plans weren’t going to work, I spent a bit of time thinking about whether or not I could apply the same kinds of methods to ice sheet models – there was a big group in Bristol that did ice sheet modelling, their main 3-D model was pretty well-written and documented, and ice sheet models were known to exhibit the kind of multiple equilibria that numerical continuation can be used to explore. Seemed like the methods I was developing would be a good fit. Unfortunately, I ran up against a little problem: in more or less all realistic ice sheet models, the boundary of the ice sheet is dynamic. As more snow falls on the ice sheet, the sheet gets bigger and its boundary extends; as ice melts, the sheet shrinks and its boundary contracts. Mathematically, this is usually expressed as something called an obstacle problem. Although these aren’t insurmountably tricky, as far as I could find out, no-one had developed numerical continuation methods for equilibria of these problems at the time. I found some theoretical papers and thought it might be possible to implement the methods they described, but it would have been a bit of a gamble, and time was getting short.

In parallel with the dynamical systems work, I had also been developing a library of dimensionality reduction and computational geometry code in C++, implementing methods like Isomap, nonlinear PCA and Hessian locally linear embedding. I decided that the best bet for producing a reasonable thesis within the allotted three years was to use this code to do some analyses on climate model output. It wasn’t the most exciting thing ever, but it got the job done, and got me my PhD.

#### Post-docs: Canada & France

After my PhD, Rita and me both got post-doc positions in Canada at the University of Victoria. Here I was employed in the maths department to work on stochastic models of tropical convection to be used as parameterisations in atmospheric general circulation models. All Fortran again, big codes, lots of MPI. Although the stochastic modelling aspect of the work was really interesting, I ended up having to do a lot of numerical analysis in this job, which is not something that I know very much about, not something that I enjoy very much, and not something that I’m very good at. My boss was really into it, and that not-quite-overlap in interests led to a bit of miscommunication and a post-doc that wasn’t as productive as it could have been. I had some ideas and some work that was going quite well on stochastic models of interactions between clouds, but that got put aside in favour of detailed work on the numerics of an existing convective parameterisation that I really made no decent headway on at all. All a bit disappointing, but I learnt a lot.

After the end of my post-doc, we stayed on in Canada for a while, and I worked at NEPTUNE Canada, an ocean observation project that’s based at the University of Victoria. There, my job title was Scientific Data Specialist, which meant that I was supposed to make sure things worked nicely for the scientists trying to use the project’s data, and worked on the development of new data products. I mostly concentrated on sonar and hydrophone data. There were a lot of problems with the way things were done at NEPTUNE at this time, with what was ostensibly a science project not being very clearly focused on the needs of the scientists. There was a big pile of Java code that had been written for data collection and archiving, and some of the design decisions that had been locked in very early on didn’t make a whole lot of sense for the kind of sophisticated sensors that people were wanting to deploy in the system. I tried to bypass some of the slow development of new software by writing C++ code to process raw sonar instrument output into formats usable by the scientists, and had some success with this. It was actually kind of fun to process some of this stuff and know that you were the first person to visualise this data that had been pulled out of some instrument on the bottom of the Pacific!

The management aspects of NEPTUNE got on my nerves though, and when Rita found a likely looking pair of post-doc positions in the south of France, we decided to leave Canada and come back to Europe. The post-docs were both in Montpellier. The fact that I quit and left before the end of my two-year contract is some indication of how acceptable the setup was. I was mostly doing data analysis and statistical modelling in R and ArcGIS, which was fine as far as it went, but I didn’t have a lot in common with most of the team, the atmosphere was bureaucratically quite stifling, and I never really felt comfortable there.

## Recent interests

Which brings us right up to date: after quitting the post-doc in France, we moved here to Austria, where Rita is in school studying to become an occupational therapist and I am working as a freelancer.

I’ve currently been focusing most of my programming time on Haskell. I feel as though I learn things when I write Haskell, and it forces me to think in new ways. It’s fun. And the weird thing is that even though it initially felt strange, it’s quite easy to get things done. I’ve been playing with Yesod, a Haskell web framework, both as Haskell exercise and as a way of learning some more about web programming, and it’s really great.

I currently have two clients I’m working with. One is my old research group in Bristol, for whom I’m writing data preparation tools (in Fortran, C++ and, of all things, Tcl/Tk!) for the work they do with the UK Met Office Hadley Centre climate model. The other is a start-up company that’s developing tools to make Bayesian statistical methods (in particular Markov chain Monte Carlo for complex models) accessible to more scientists. This is nominally a Haskell contract, with a backend based on Yesod, but I’ve also been doing a lot of JavaScript work for the front end, including a data visualisation library that works with AngularJS – that’s still at a relatively early stage of development, but I think it’s quite neat and might be something that could be pretty useful.

In my totally inadequate spare time between paid work, I’m going to try to “Haskellise” some of the huge pile of unfinished and nascent ideas that I have lying around. Should be fun!

1. Computers have got smaller over the years. Washing machines, not so much.

2. Perhaps it was for the best that the very nice system admin at the University of Bristol refused to grant us access to their Multics mainframe, no matter how keen we were and no matter how much experience we’d had mauling our GCOS system…

3. One of the people there did point me at Fred Brooks’ The Mythical Man-Month, which I still have on my bookshelf and consult regularly.

4. Looks like Unix, feels like MVS. I think it was one of the first Unix-a-likes to introduce a memory-exhaustion process killer, which was fun. It also had a journaled file system, which meant there wasn’t time to go out for lunch while rebooting after a power failure.

5. Yes, I really have been paid actual cash money for programming in APL. We spent a whole afternoon once debugging one line of APL, and fixed it by changing one character. That’s hardcore.

6. In particular, a little X application for network-aware post-it notes, so that traders could slap little stickies on each others’ screens – more direct and harder to miss than email, which they liked.

7. My main manager tried to reassure me that it was OK: “We don’t make anything that actually goes bang!” he told me…