Imperial College London

Henry Rzepa

Computers and I go back a while (44 years to be precise), and it struck
me (with some horror) that I have been around them for \~62% of the
modern computing era
([Babbage](http://en.wikipedia.org/wiki/Charles_Babbage){target="_blank"}
notwithstanding, \~1940 is normally taken as the start of the modern
computing era). So indulge me whilst I record this perspective from the
viewpoint of the computers I have used over this 62% of the computing
era.

1.  1967: I encountered (but that term has to be qualified) my first
    computer, suggested to me as an alternative to running quarter
    marathons on Wimbledon common at school by an obviously enlightened
    teacher! I wrote a program (in Algol) on paper tape, put the tape in
    an envelope, and sent it off to Imperial College (by van) to run, on
    an [IBM
    7094](http://en.wikipedia.org/wiki/IBM_7094){target="_blank"}. A
    week later, printed output showed you had made a mistake on line 1
    of the program. As I recollect, after about eight weeks of this, I
    got the program to run (and calculated π to 5 decimal places).
2.  1970: By now I was a student (again at Imperial College), and was
    introduced to Fortran, then a radical new innovation to a chemistry
    degree. The delightfully named
    ***[pufft](http://dx.doi.org/10.1145%2F365660.365671){target="_blank"}***
    compiler combined with the 7094 again, but this time with punched
    Holerith cards as input and line printer output. I cannot remember
    what we were asked to program. I do remember that the punched cards
    were produced by a pool of punch card operators, working from code
    pages written by the programmer. Some students (not me!) thought it
    great fun to give their Fortran variables naughty names (which the
    punch card operators then refused to punch, thus causing the student
    to fail the course!).
3.  1971: I really liked this programming lark, so when
    ***instant-turnaround*** was introduced that year, I decided to do a
    proper program. It was called NLADAD (yes, I was no good at names,
    even then), which stood for non-linear-analysis of donor-acceptor
    complexes. The idea was to take recorded NMR chemical shifts, and
    fit them to an equilibrium A+B ⇔ AB+B ⇔ AB~2~ using non-linear
    regression analysis. It must have been all of 200 lines of code (OK,
    I did not write the matrix inversion routine myself)! Instant
    turnaround was also great, you got to punch your own cards this
    time, and had the great excitement of feeding them into a card
    reader yourself. You then walked about 5 yards to the line printer
    and waited agog. No waiting one week, this was less than a minute.
    Or it would have been if the line printer did not paper-wreck every
    two minutes! (I might add that I have a dim recollection of a member
    of the computer centre staff standing by to recover these paper
    wrecks. He, by the way, is now the director of the ICT division
    here!).
4.  1972: I am now doing a PhD (yes, boringly, yet again at Imperial
    College). I had found the one and only teletypewriter in the
    chemistry department. The crystallographers had secreted it away in
    their empire, but were very dismayed to find me occupying it
    constantly. Instant was now even more instant. I was now connecting
    to a time-sharing [CDC
    6400](http://en.wikipedia.org/wiki/CDC_6400){target="_blank"}
    computer, at the dazzling speed of 110 baud (or bytes per second).
    These were small bytes by the way, since the CDC used 6 bits per
    byte. The result was that one did everything in UPPER CASE, since a
    6-bit byte only allows 64 characters! My (still Fortran) programs
    reached probably 1000 lines of code now, and I was engrossed in
    deriving non-linear analyses of steady state chemical kinetics
    (about four different kinds of rate equation as I recollect). Ah,
    the joys of covariance analysis, and propagation of errors (I was in
    a kinetics lab, and all the other students plotted graphs on graph
    paper, and if pressed, plotted gradients of graphs, the so-called
    Guggenheim plots. I thought this the dark ages, but no-one
    volunteered to join me in this single teletypewriter room. Not even
    the attractive girls in the group. I was the geek of my time, no
    doubt about that. My kinetic analysis did however have one upside.
    Its how I meet my wife to be a few years later!).
5.  1974: PhD completed, I was now ready to go to Texas, where
    everything is bigger (and in terms of computers, slightly better, a
    [CDC 6600](http://en.wikipedia.org/wiki/CDC_6600){target="_blank"}
    now and a 300 baud teletypewriter!). I had been computing now for
    seven years, and finally I actually got to SEE the device for the
    very first time. My mentor, Michael Dewar, had a sort of special
    relationship with the university. His students (and possibly only
    his students) were allowed to go into the depths of the machine
    room, where behind plate glass you could see the CDC 6600. I soon
    learnt how to get even closer. It was not particularly exciting
    however. I was more entranced with the
    [CALCOMP](http://en.wikipedia.org/wiki/Calcomp_plotter){target="_blank"}
    flatbed plotter, which was located next to the 6600. Pictures at
    last (you probably do not want to know that to convert my kinetics
    in 4 above to pictures, I got quite expert in using a [french
    curve](http://en.wikipedia.org/wiki/French_curve){target="_blank"}.
    Look it up before you jump to conclusions). Part of the pact I
    negotiated was that I was only allowed into the inner sanctum at
    03:00 in the morning (sic!). Still a geek then! Oddly, I was one of
    the few students in Dewar's group using the CALCOMP, but at least
    [we now had](http://dx.doi.org/10.1021/ja00444a012){target="_blank"}
    pictures of the molecules I was now calculating (using MINDO/3). To
    put the computing power into context, in 1975, Paul Weiner, another
    group member, announced that he had completed a full geometry
    optimisation of LSD, this having taken about 4 days to do on that
    over-worked 6600. The entire group went out to celebrate. Many
    pitchers of beer were drunk that nite.

    ::: {#attachment_4559 .wp-caption .aligncenter style="width: 410px"}
    [![](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/esca.jpg "esca"){.size-full
    .wp-image-4559 loading="lazy" decoding="async"
    aria-describedby="caption-attachment-4559" width="400" height="387"
    srcset="https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/esca.jpg 991w, https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/esca-300x290.jpg 300w"
    sizes="(max-width: 400px) 100vw, 400px"}](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/esca.jpg)
    Computer graphics from 1976.
    :::
6.  1977: Back to Imperial, where we might have also now had a CDC 6600.
    And a Tektronix terminal running at the dizzying (hardwired
    end-to-end) speed of 9600 baud. I learnt to Word process on this
    device (using a word processor, written in Fortran, although not by
    me) and I wrote three review articles by this means, using a fancy
    phototypesetter as the printer. My next program, STEK, probably ran
    to about 5000 lines of code, and it persuaded the Tektronix to [plot
    all sorts of things](10.1039/P29890002115){target="_blank"},
    ball&stick diagrams, isometric potential surfaces, molecular
    orbitals, and the like (and jumping ahead, my experience with this
    program eventually led to CML, and Peter Murray-Rust, but that is
    indeed jumping ahead). I think I also managed to gain access to the
    Imperial machine room, that inner sanctum, yet again. But for
    reasons I will not go into, it was not as interesting as the Texan
    machine room.

    ::: {#attachment_4566 .wp-caption .aligncenter style="width: 310px"}
    [![](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1987g.jpg "1987g"){.size-full
    .wp-image-4566 loading="lazy" decoding="async"
    aria-describedby="caption-attachment-4566" width="300" height="521"
    srcset="https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1987g.jpg 575w, https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1987g-172x300.jpg 172w"
    sizes="(max-width: 300px) 100vw, 300px"}](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1987g.jpg)
    Chemistry Computer graphics, circa 1977-85.
    :::
7.  1979: I encountered a [Cray 1
    computer](http://en.wikipedia.org/wiki/Cray-1){target="_blank"}, and
    probably also 8-bit bytes (and yes, lower case printer outputs) for
    the first time at the University of London Computing Centre.
8.  1980: Remember that teletypewriter, encountered earlier. Well these
    were now running at 2400 baud and I started to organise the
    deployment of a chemistry department computer network to sprinkle
    several such terminals around the department. The controller was a
    [PAD](http://en.wikipedia.org/wiki/Packet_Assembler/Disassembler){target="_blank"},
    and in that year, we introduced STN ONLINE using this network. It
    was the first time we could search CAS online ourselves (previously,
    it was a service offered by the library). Literature searching has
    not been the same since.
9.  1980: I finally again encountered a real computer, which one could
    happily listen to without creeping into machine rooms in the middle
    of the night. It was the data system on a Bruker Spectrospin 250 MHz
    superconducting NMR spectrometer. I had [many
    adventures](http://dx.doi.org/10.1039/C39820000482%20){target="_blank"}
    on this system. It was installed, by the way, on more or less the
    same day as the birth of my first daughter Joana. It had a hard
    drive (5 Mbytes as I recollect, and cost an absolute fortune, around
    £10,000 if I remember correctly).

    ::: {#attachment_4574 .wp-caption .aligncenter style="width: 410px"}
    [![](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr1.jpg "1982-nmr1"){.size-full
    .wp-image-4574 loading="lazy" decoding="async"
    aria-describedby="caption-attachment-4574" width="400" height="300"
    srcset="https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr1.jpg 808w, https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr1-300x224.jpg 300w"
    sizes="(max-width: 400px) 100vw, 400px"}](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr1.jpg)
    Combining Quantum mechanics and NMR.
    :::

    ::: {#attachment_4571 .wp-caption .aligncenter style="width: 410px"}
    [![](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr.jpg "1982-nmr"){.size-full
    .wp-image-4571 loading="lazy" decoding="async"
    aria-describedby="caption-attachment-4571" width="400" height="282"
    srcset="https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr.jpg 821w, https://www.ch.ic.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr-300x211.jpg 300w"
    sizes="(max-width: 400px) 100vw, 400px"}](http://www.ch.imperial.ac.uk/rzepa/blog/wp-content/uploads/2011/07/1982-nmr.jpg)
    Computer graphics 1982, from NMR spectrometer.
    :::
10. 1982: More networks, this time a curious computer known as the
    [Corvus
    Concept](http://en.wikipedia.org/wiki/Corvus_Systems){target="_blank"},
    using a networked hard drive (possibly as big as 20 Mbytes by now),
    and a large screen.
11. 1985: Enter the Mac (OK, the IBM PC came a little earlier, but it
    was not entrancing). Now one really had a tactile computer that made
    noises (not always nice), produced smoke signals occasionally, and
    ejected its floppy disk incessantly. Yet another revolution to cope
    with. As I type this, I look down on that Mac, which is still
    underneath my desk. Wonder if its worth anything on ebay?

Well, a second consecutive blog, with (almost) no pictures or molecules.
And I have only gotten to the [half way
stage](http://www.ch.imperial.ac.uk/rzepa/blog/?p=4578){target="_blank"}
of my story. Better break off then.

::: {.wp_orcid_field}
[https://orcid.org/0000-0002-8635-8390](https://orcid.org/0000-0002-8635-8390){target="_blank"
rel="author"}
:::


Computers and I go back a while (44 years to be precise), and it struck me (with some horror) that I have been around them for ~62% of the modern computing era (Babbage notwithstanding, ~1940 is normally taken as the start of the modern computing era). So indulge me whilst I record this perspective from the viewpoint of the computers I have used over this 62% of the computing era.

Messages de Rogue Scholar

Computers 1967-2011: a personal perspective. Part 1. 1967-1985.