This article was contributed by Graham Denton in 2009.




One of the earliest things I remember from my schooldays (which started in 1953!) is not being able to learn my multiplication tables – does anyone still learn these nowadays?  I also disliked school and so avoided doing any more work than necessary (a habit I preserve to this day) so, I suppose, it was not unnatural that I became very adept at using my fingers when doing sums and, later, that I so willingly embraced any form of technology that would help make these calculations easier.


These notes look back, from a personal point of view, at the changing face of the technology I have used and the way that computers (using the term in the old sense – something or somebody that calculates) have appeared on the scene and then changed beyond recognition.  In places I have simplified and, sometimes, omitted machines I have used but I have done all possible to remain accurate throughout.


Some the older technology I used is unheard of now and it was only quite recently that somebody . . .     No, perhaps I should start at the beginning!



School and College


Having progressed a bit from the use of my fingers, which were of course my first ‘computer’, one of the things we had to learn in our maths classes was use of tables of logarithms (log tables) – in fact, not only were we allowed to use log tables to perform calculations but we were also examined on our ability to do so.  Perhaps this is a bit like an early form of modern data processing exams.


Having moved on to college we were allowed the great benefit of using slide rules.  I started with a second-hand wooden one and progressed to a higher quality plastic one that I still treasure - even though it is now of no real use other than a conversation piece.  I took it in to work a while ago to show it to one of the younger engineers who had heard of them but never seen one; though when I mentioned this recently one of his colleagues hadn’t even heard of them.


Electronic calculation was still to come, though things were beginning to change.



Arrival at Work


It should first, perhaps, be understood that I (and I still sometimes wonder why!) chose to enter Engineering – not just Engineering but electro-mechanical engineering where I needed to perform repeated calculations to a great accuracy.  The equations were not, generally, complex – but they were certainly repetitive and needed to be done to significant accuracy!  My log tables and slide rule become my inseparable friends but, for greater accuracy, I learned to use something else – the mechanical calculator!


This was an ‘Original Odhner’ – a contraption of gears, sliders, cranks and ratchets that could, by turning a handle, be made to multiply and divide numbers to an accuracy of 10 significant figures.  It took a while – but it could do it!  It couldn’t add or subtract, but we could do that with pen and paper so it didn’t matter.


This, then, was the situation when I started trying to make my living doing the thing that had been so difficult at school.



The First Electronic Calculator


One of the tasks I was given, with another engineer, was to investigate and write a justification for purchasing, for use in the engineering laboratory, one of the newly available electronic calculators.  We considered this and, because we had to do a lot of right-angled triangle calculations (X2 + Y2 = Z2 – remember that? No? Never mind!) we decided on a quite demanding specification;  It must do all four arithmetic functions (Add, Subtract, Multiply and Divide); It must have a store that can hold a result that we can recall and re-use later and, most difficult of all, it must be able to calculate square roots!


We satisfied this incredible specification and were allowed to purchase a mains-powered machine, made by Hitachi, that took up half the desk (perhaps an exaggeration but I remember it that way) and cost around £200 – that may not sound much but, at the time, it was probably over 2 months salary to me (fortunately, I was not paying for it personally!)


This new machine was in great demand, the engineers almost queuing up for it - in fact, sometimes literally queuing up for it!  I remember waiting for the chance to get it to process my test data and then, when I had it, the constant queries from others – “How long will you be?”



The Arrival of Pocket Calculators


I feel sure that our desktop calculator would still be in use now except for one characteristic of modern electronics – the size was reducing almost as fast as the price!  Gradually, we all began to swap our trusted slide rules for pocket electronic calculators.  I remember deciding that I would buy one when I could get the same specification as we had used for our laboratory calculator but for no more than £20.  I think that it was around 1973-4 ish that I bought a Prinztronic SR88M (it was serial number 517088) – from the Dixons own-brand range.


These early calculators were great toys for engineers.  With their bright LED displays that consumed batteries faster than we could buy them they were more accurate then a slide rule though perhaps no faster (a slide rule in skilled hands was an amazing device) and did little else.  What we really needed was a calculator that could remember how to apply the equations so that it could produce an answer with us only having to enter the raw data.




My Colleague’s Digital Watch


The same technology was appearing in items which, at first sight, were not computers (they were really but that is another debate) including early digital watches.  No – I never bought one (they seemed particularly useless to me) but one of the lads in Sales dept did. Like the calculators these had LED displays (liquid crystal was still unheard of then) and, because of the high battery drain, the wearer had to press a button on the watch to make it display the time for a few seconds.


The battery in this persons watch had, I subsequently heard, gone flat but he continued to wear it until he could get a replacement battery – it was useless as a timepiece but, I gather, he thought it made him (as some may now say) ‘look cool’.  Unfortunately, it seems that some of the girls in sales found out.  After being asked the time by several of them in turn the watch went into his pocket and we never saw it again – ever!




The On-Line Computer


I am not sure how I discovered that the company had a ‘computer terminal’ and even less sure how I got permission to play with it (such things were normally reserved for accountants and the like – not menial engineers).  I did, however, get to use it – a teleprinter style terminal (what’s a VDU?) on the end of a telephone cable.  I never found out where the cable went or what was on the other end but that didn’t really matter; I was allowed to use it, though I was made well aware that we had to pay some exorbitant rate per second for the processing time that was logged to us.


The real benefit was that the calculations suddenly became much simpler.  I ‘told’ the terminal how to process my data and then, whenever I had fresh information to process, I could just type in the numbers and then it would burst into life, clattering away as it printed out the results of my calculations, apparently without hesitation.  Of course, ‘telling’ the terminal how to process the data was easier said then done – I had to learn to program in BASIC (and also had to learn how to type!).



Our First Desktop Computer


Fortunately, we had an engineering director at this time who loved toys as much as the rest of us and was quite happy spending company money to buy them (in fact, I am sure he had to justify the expenditure but that was not my problem!).  This is how we came to get our first desktop computer in the laboratory – an IBM PC.  Its small monochrome (meaning Black and Green) VDU replaced the clattering teleprinter and its 5 ¼ inch floppy disk drive allowed me to store my programs and data, though now I had to learn something called DOS. It came with built-in BASIC and we bought project management software for it – my first experience of using purchased software, as opposed to my own BASIC programs.  I remember loading up the software from the floppy disc whenever I wanted to use it, and thinking how great it was.


I must be forgiven for relating a story about this computer.  Our engineering director normally started it up and used it first thing in the morning (not sure what for – all that mattered to me was when would he finish so that I could use it).  I discovered that he was shortly to have his 40th birthday.  A few late nights working on my own and some interesting programming meant that I was able, the night before his birthday, to leave a special floppy in the drive.


Next morning, I waited whilst he stated the computer.  Once started, the number 40 was prominently displayed on the screen and the computer played ‘Happy Birthday’ for him.  No sooner had the tune finished than he came round and accused me of doing it, though I had taken care not to leave any clues!  Unfortunately, he pointed out the one give-away; he said that I was the only one who would know how to do it.  It was, of course, all good natured and I retained my job.



More Computers


Gradually, more computers were purchased for communal use so our access to them improved greatly.  It was either the second or third one we had that included a ‘hard drive’ – utter bliss, no more floppy disks to take care of!  Programs, data, it was all stored on the hard drive – after all, space was not limited; we never thought we could fill a 10Mbyte drive (Yes – Mbyte!).


We eventually had around 4 (I think) of these IBM PCs available to us.  Almost all of my engineering calculations were now being done by BASIC programming the first time I needed to do something and then by just using the program to do the hard work for me later.


I recall commenting to the data processing manager one day that I wasn’t doing anything clever with the computers; I was doing the same calculations but the computer did the donkey-work for me.  He pointed out, of course, that this is the clever thing to do with computers. In fact, we did get other benefits – because the calculations could be done much more quickly we were able to pursue the designs to a greater depth and accuracy so our work must have improved as a result of the use of the computers.


By now, early 1985, use of computers was an everyday experience for us but, although I didn’t know it, I was about to get an even better toy!





Anyone remember what a pencil is?  It may be difficult to believe but up to this time (only just over 20 years ago) new designs were drawn, using a pencil, on a piece of processed tree called ‘paper’.  Our engineering department had around 6 draughtsmen and the production drawing office took up a whole floor of the building.  The drawings were taken by another group of people who worked out the commands to make the automatic machines in the factory produce the parts – the commands were fed to the machines using punched paper tape.  These machines would then produce something resembling the original drawing.


It was the mid-1980s and all this was about to change.


The company decided to invest in Computer Aided Design (CAD) and Computer Aided Manufacture (CAM); put it together – CADCAM.  A quarter million pounds later (VERY glad I wasn’t paying for that!) we had a MicroVAX computer running 4 workstations.  I do not remember the capacity of the main storage disk, though I do remember a later upgrade to 1Gb.  We could do mechanical design and drawing on the workstations and then semi-automatically produce the tapes for the machines – and guess who had the job of running it all!!!!  I found myself learning new operating systems (DCL), new languages (FORTRAN and a touch of C), how to control databases using SQL – officially, SQL meant Structured Query Language, but we always said that it meant Some Queer Language (interesting how language changes – ‘Queer’ then just meant Odd).


This era was interesting to say the least – I’m not sure if it was heaven or hell; probably a bit of both.  I recall a comment made by the instructor at the end of a 1 week DCL course I attended in Manchester – he said that if we thought that was difficult we should try the system managers course.  He did not know but I was going back for that the next week!


This was, at that time, quite an advanced step for a company of our size to take, and a major investment.   In order to demonstrate the power of the system to the company’s, perhaps sceptical, managers we arranged a 1 hour presentation.  Within that hour I introduced and explained the system, we drew a simple part, electronically of course (no paper involved) and created the paper tape for the machine tools.  We stopped short of actually running the machine – we had run out of time and, probably, courage!


After a period of use the system became a little sluggish and I imagined the files, by now, to be thinly spread across the disk in many tiny pieces.  Now, one of the shortcomings of the MicroVAX was that it had no disk defragmenter and I was not about to stake my career on an untested item of third party software.  The solution, whilst not complex, was lengthy.  After normal working hours one Friday (work finished early on Fridays) as I started the defragmentation process one of the users, who would be working on the Saturday, joked “See you in the morning!”  I started with a full system backup (to tape, of course), then deleted unnecessary data (log files, etc.), copied all data files to tape (a process which, inevitably, makes them contiguous), nervously deleted the files from the disk and, finally, copied them back to the disk.  I recall several cups of tea with the security staff in the gatehouse whilst the tapes were running.  On Monday morning I checked the log-in times and found that I had only missed the joker by about a half-hour (he only thought he was joking).  After an hour or so I asked one of the main users how the system was performing – was it any different to Friday – “About the same” came the answer!


I enjoyed my time in CADCAM but, looking back, perhaps the most significant point is that this is the only time that my role, my job function, has been changed by a computer.



Who Stole My Toys?


I enjoyed around 5 years playing with my MicroVAX and its successors (Sun Workstations running UNIX – but let’s skip over that or I’ll be here all night) before a promotion took me back into design but at a level where I had little time to get involved with the detail of the computers.


Then, I changed employer.



Two Computers On My Desk!


In 1995 I took on a project management role with another local company.  Now this company was quite advanced in its thinking and all (I think) of the engineers had computer terminals on their desks.  Unfortunately, these were only terminals from a mainframe – they could access stock records and cost data, they could even do a little word processing – but not much more.  The problem was that I, as Project Manager, needed project management software.


The mainframe could not run any suitable software so the only solution was to provide me with a PC as well as the terminal – I think I was the first (possibly only) person to have two toys to play with at the same time!


In fact, this didn’t last long.  Gradually, the old system was replaced and we all had networked PCs and increasing amounts of software became available.  Spreadsheets had, by now, replaced most of my old BASIC programming, though interestingly I have, more recently, created routines using VBA embedded within Excel to automate data entry, calculation, graph plotting, etc. – perhaps coming full circle back to programming.


It was during this era that I was tasked with investigating computer modelling.  Until then, we had to build a prototype of a new design and test it – the idea was to ‘build and test’ it on a computer.  When it was announced that I would get involved with modelling I suffered the inevitable comments about not having the legs for it!


Over the next 10 years almost all aspect of computing continued to develop, though this is in recent memory so it is probably not of interest to relate it here – software, data storage, the Internet, e-mail, etc.  Looking back, I have continued to enjoy my association with computing through these times but, perhaps, it lacks the excitement of earlier days.  It’s rather like buying a new car – however nice it is; however much you enjoy driving it; it will never be quite like the excitement of buying your first car.



Enter The Dragon


Toys, of course, are not just for work and I was watching the development of home computers carefully.  I eventually (around 1980ish) purchased one of the early home colour computers – a Dragon 32.  We needn’t worry about the technical details (I could ramble on interminably about that) but it is interesting that the ‘32’ indicated that it had 32kbyte of RAM (‘k’, of course, means 1000 so 32kbyte = 0.000032Gbyte).  It used a domestic television as a display – monitors were expensive – and a domestic cassette recorder for storage of both programs and data (A hard drive?  Don’t be silly!).  I did upgrade with a floppy disc drive when they became available for it but this was still a toy or, as some would prefer to say, a hobbyist computer.


I enjoyed programming in its built-in Microsoft BASIC (thank you, Bill) and gained great pleasure from seeing the computer do what I wanted – even if it was not particularly useful.  I recall writing a few games but never played them – the pleasure was in the programming and when the game was working it was of little further interest.


A couple of things were about to change this.



Serious Home Computing


The price of printers was falling and I bought a second hand ‘Oki Microline 80’.  I think I paid around £60 (not sure) for this device, with its crude monochrome dot matrix typeface – around twice the amount I recently paid for a modern picture-quality combined ink jet printer and scanner!


There also became available a piece of software for the Dragon (purchased on cassette tape, of course) called ‘Telewriter’.  This was a word processor.  The Dragon screen resolution was not good enough to represent the complete width of an A4 sheet (or was it still ‘foolscap’ then?), in fact, very few computers were but it did allow words to be laid out, edited, re-sequenced, etc.  It put in symbols to show where bold, italic, etc. started and finished, as well as symbols for new lines, and the like – all I had to do was imagine what the finished page was going to look like!  This may sound crude (that’s because, by modern standards, it was crude) and it is difficult, now, to understand the amazing advance that it was.  This, together with the printer, made my wife’s typewriter obsolete overnight.


The real significance, however, is not the benefits of home word-processing – it is the change this caused in the role of my Dragon – it was no longer a toy (at least, not all the time); it had a serious purpose in the home and it began to earn its keep.



Arrival of St. George


We all know that St George killed the Dragon and he arrived in a number of forms for these computers; other home micros, dedicated games machines and, of course, affordable ‘PCs’ as we now know them.  In my case, St. George arrived in 1994 and took the form of a PC which, even if of very low specification by modern standards, is clearly recognisable as what we now know as a PC.  Even that has now been superseded but, whilst the PC went to the local dump, my Dragon escaped and hid in my loft for some years – it now lives in happy retirement at the Museum of Computing at Haverhill!


My Father had also bought a Dragon 32 (all credit to him – not many retired people were embracing this new technology) and his continued in use until the late 1990s – I wonder if this was the last working Dragon?



My Current Home Computers


Sadly, perhaps, I am not sure that my home computer qualifies as a toy anymore.  It sits in the corner with its e-mail and Internet connections and is a functional piece of equipment – very much like the telephone with which it shares the desk.  Rarely do I pick up a pen or go to the library; I just reach for the keyboard.  Instead of draws of paper records it is all on my hard drive.  This applies equally at home and in business.


There is, however, always a brighter side and, whilst writing these notes, I installed a wireless router at home.  A technical complication made this more complex and time-consuming than it should, perhaps, have been and whilst sorting this out there was again just a slight feeling of playing with my toys (though I must observe that my wife was more interested in the match of the router’s colour to the wallpaper – something to do with the difference between engineering and the arts!)


I must reflect not only on the skills I have learnt (and there are many) but also on those that I have lost.  For example, I could once sit and dictate a document, composing it as I went.  Now, I can only compose on the keyboard, getting the words down haphazardly and then rearranging and editing to get the final version.  As for spelling and handwriting . . . .      I do not suggest that any of this is better or worse – only that it is different.


The real impact of computers lies, not in the computer that sits on my desk, but in all the computers that we do not see; those embedded in various items around the house – indeed, around the world.  They are at the heart of not only obvious items like my mobile phone and digital TV recorder, but also more obscure things; even my washing machine.  I do not know how many computers I use every day – I suspect that I would be surprised.



And Finally


We have come a long way since the days of my slide rule, though it will always have a special place in my memories.  Inevitably, however, we have considered the changes – but what of the things that have not changed?


I am struck by the fact that, with the possible exception of a few years in CADCAM, I have generally done the same basic job – design engineering.  I have used newer and shinier tools to do it; I may have done it better and more quickly because of those tools; but, fundamentally, the underlying task has been the same.


Inevitably, I wonder what the world would be like without computers.  We automatically imagine somewhere very different from the place where we live today.  I would never wish to dispute the benefits and advantages that electronic computers have brought to engineering.  I would certainly never dispute the skills and contributions of those that made this possible.  I must, however, observe that my personal engineering hero (I. K. Brunel 1806-1859) achieved everything he did with no more than a slide rule.

(Graham Denton – Composed May-June 2009)

Date : June 2009

This exhibit has a reference ID of CH40295. Please quote this reference ID in any communication with the Centre for Computing History.

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