back to article Bletchley Park to rebuild pioneering EDSAC computer

Bletchley Park is to rebuild one of the world's first modern computers. The Electronic Delay Storage Automatic Calculator (EDSAC) was put together at Cambridge University in the late 1940s as a tool for researchers and scientists. The room-sized valve-based system, designed and developed by the late Sir Maurice Wilkes, first …

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  1. hplasm
    Big Brother

    mercury is not a geat a hazard-

    as Heath & Safety zealotry is.

    1. Ian Yates
      Troll

      Mercury

      To be honest, they probably have opted to not use mercury themselves and H&S is just one reason given. Cleaning up a mercury spill is not a simple job.

      Sure, if you don't care you can get it done quickly, but I wouldn't want to be exposed to mercury vapours. But feel free to march over there and proclaim that you'll rebuild it with mercury yourself.

      I guess you also think the way people handle asbestos is just H&S zealotry?

      (Have I been trolled?)

      1. John G Imrie

        Mercury

        We used to roll balls of mercury up and down the desks of the science lab at school and it hasn't effected wibble wibble zxoop

        1. Anonymous Coward
          Anonymous Coward

          Trying

          to catch them in a handkerchief was fun.

          This may be part of the reason I have already forgotten why we're talking about mercury

      2. hplasm
        Grenade

        I'll rebuild it with mercury myself.

        Like those that did it originally.

        I don't recall them entering the hatting trade either.

        Asbestos is not mercury.

        Are you American? You panic like one... Look out- a fluorescent lamp!!

        (You have been now...)

      3. peter 45
        Dead Vulture

        Ever been to a mercury factory?

        I suppose you would imagine people in white suits and breathing masks working behind glassed off areas. Well you would be wrong. Mercury runs down open channels , no masks etc. The difference is that there is adequate ventilation. Chronic exposure to mercury vapours happens in two ways. 1. concentrating the vapour by boiling it. 2. at room temperatures, prolongued exposure over many years. Yes it is toxic, and no, you do not want to injest it or inhale it and minimising the long term exposure of it is a good thing, but please do not go down the scare story of 'one breath and you are dead' routine.

        1. Ian Yates

          Mass reply

          No, I'm not American and I'm not terrified of mercury.

          My link to asbestos was because they're both dangerous (increasingly) due to length of exposure and are both treated as hazardous material.

          I would imagine breathing masks in a "mercury factory" and overalls (not necessarily white), but I didn't immediately think of glassed off areas. Probably rubber gloves, though.

          I spent a while searching for mecury factories/refineries/production/etc. but didn't come up with anything worthwhile.

          I didn't say "one breath and you are dead", but I can see how my original post might have read more scaremongering that it was meant. I was just saying that I wouldn't put myself in a position of risk if it was unnecessary (and not fun).

          To be honest, IANAL but I don't believe Bletchley Park /couldn't/ use mercury due to H&S (which was the reason for my original post), they've probably chosen to do so because of h&s. In other words, why risk exposing people to a potentially dangerous substance if you don't need to? Just go with Turing's idea and use gin!

          @Graham Wilson: I'm not going to address every point, but 4 confuses me. OHSA and H&S do not inhibit using mercury, they merely define how to reduce occupational exposure and personnel risk.

          OHSA don't even list it in their "highly hazardous" list of chemicals (and yes, I know what a chemical is).

      4. Allan George Dyer
        Coat

        I thought the way to handle mercury...

        was to chuck down a sink and leave it there, blocked, until it eats through the lead U-bend years later and some poor smuck finds it leaking onto the floor.

        At least, I've always assumed that was the explanation for the sink in my old lodgings (a former hatter's workshop).

        I'll get my coat, did I have a hat? I don't remember.

      5. Graham Wilson
        Flame

        @Ian Yates - You don't have to be exposed to its vapour to actually use mercury!

        1. You don't actually have to be exposed to its vapour to use mercury--have you ever heard of containment?

        2. Read peter 45's post. It's a good summary of the practical dangers. You might also consider reading my long post further down, it covers similar issues in more depth.

        3. Don't forget we humans have used quicksilver (Hg) for thousands of years, we've now a damn good idea how to handle it in ways that do not make us sick.

        4. Unfortunately, these ways often do not coincide with EPA, H&S or OH&S laws and we end up with the ridiculous situation that's happening at Bletchley Park (where it seems the integrity (authenticity) of the project will be smeared as a consequence of these laws).

        5. In the '70s and '80s, when these laws were initially being framed, we 'precious' techies--like Pontius Pilot--washed our hands of the H&S problem. We weren't law makers or politicians and we didn't want to sully our hands with or lower ourselves down to the messy business of 'regulation'.

        5.1. Now we've been bitten by it. Instead, of effective sensible regulation, we've been left with zealot-like overregulation or regulation that ties everyone up in knots to the point where nothing ever gets done, or both.

        6. Not only have we techies lost control of the H&S legislation but those who've taken up its cudgels are a bunch of postmodernist, Golgafrincham-like technocrats whose lofty aims and ideals in life extent to little more than ensuring that workers' battery-powered screw drivers conform to 50-bulletpoints of regulation before being allowed onto building sites. Seemingly, it's this kind of logic that's behind the 'mercury at Bletchley' problem.

        7. In the time we techies were doing our Pontius Pilot routine, the anti-science-ers, soothsayers and postmodernists convinced the world that everything technical, chemical or scientific is super-dangerous or has evil intent. It's why the subheading of this El Reg 'Bletchley Park' article (below) is subversive, even if it was meant in jest by the writer.

        "Will omit deadly 1940s mercury-based memory"

        8. Why? Because the Cretins mentioned in items 6 & 7 have, over a generation or so, scared the shit out of the population when it comes to many things technical. Society, with respect to matters of science and engineering, is now becoming scared of its own shadow.

        8.1. Thus (as indicated here), over a period of about the last 30 years, mercury has gone from a potentially dangerous material that needs to handled with care to one that's now classed as 'deadly'.

        8.2. Suddenly, 'deadly' mercury is being elevated to same status--at least in the minds of the public--as truly deadly life threatening products such as VX nerve gas or botulinum toxin when in practice it is nothing of the sort. Not only is this unscientific but also, it's dishonest and deceptive in the extreme, as things in science have actual measures put on them, whereas here we've the emotive, non-extensible philosophical notion 'deadly' applied to mercury. By definition, all simple notions in philosophy, good, ugly, beautiful; etc., exist intrinsically without measures; for example, 50% of 'good' is meaningless.

        9. Moreover, their marketing is slick and masterful. Armed with wonderfully sensitive technologies invented by us scientists, techies and engineers such as the gas chromatograph and mass spectrograph etc., these zealots are marching all over the planet measuring things and publicizing the results, often out of context. For example, the extreme sensitivity of these instruments will detect a few molecules of say dioxin but detecting them several hundred metres downwind of a normal campfire is meaningless (as camp files always produce small amounts of dioxin), yet such results are blown up out of all reality and presented as a crisis. This is not science at work.

        10. Like a four-year-old's belief in Christmas, non-technical lawmakers become goggle-eyed at the technology and enshrine meaningless nonsense and gobbledygook into law. In the meantime, those of us who understand the scope of such measurements, are left out in the cold.

        11. As I see it, it's incumbent on all of us nerds, techies, scientists and engineers who know and understand the facts to make a stand to stop our descent back into the dark ages. Making our displeasure known over the 'fake' mercury-less computer that's about to be installed at Bletchley Park would be a good place to start.

        1. Anonymous Coward
          Anonymous Coward

          @Graham

          A few things:

          1) Health and safety is a good thing, it has saved thousands from death or serious indjury. Don't confuse the "you can't use a ladder it's not safe" lot with people who have anything to do with H&S proper.

          2) My partner used to work with mercury in the oil industry, here are some of the (sensible) precautions they had to take:

          Ambient temperature has to be kept below the point where the mercury will evaporate.

          You have to have very good air processing to keep vapour down.

          Mercury has a habit of getting everywhere, so you have to have a clean room/dirty room setup in order that your outside clothing doesn't get mercury on it.

          Monthly urine tests are taken to measure (IIRC) kidney function to indicate mercury absorbed into the body.

          Those precautions pretty much preclude a small underfunded museum making use of large amounts of mercury to which the public will have access. The cost of urine tests for the staff alone probably make it undoable. Bear in mind that the delay lines will also be right next to an un-airconditioned valve based computer, which if the colossus is anything to go by, will be chucking out about 5KW of heat.

          This is not an elf'n'safety gone mad story.

          1. Graham Wilson
            Unhappy

            @Anonymous Coward--Perhaps I sympathise with the H&S issues more than I indicated.

            Surprisingly, I agree with most of what you say. Perhaps I sympathise with the H&S issues more than I've indicated thus far, précising key issues into posts when one's not Shakespeare is quite some task.

            First, H&S legislation was necessary and it was a logical progression from what had gone previously, (specific industry regulation etc.).

            Some background:

            1. I was in industry before H&S legislation, so I've seen the changes.

            2. As a manager, I had to implement much of the H&S legislation.

            3. I've had to directly employ staff (doing interviews), and I've seen firsthand some the problems with changes to the education system (and concomitant (extra) training that's necessary).

            4. I don't own the operation nor do I have shares, so vested interest in maintaining the status quo was/is minimal.

            5. I've had to review outcomes and changes--directly summarise the benefits and failures.

            I've had more than just work interest in the subject and I believe most of the H&S changes were necessary (I know, saying is easy, convincing you is another matter).

            H&S has made remarkable strides over the past 100 years or so and it's easy to be cocksure about things from immediate hindsight but it's much harder over the longer term (and longer term issues are now becoming obvious). H&S legislation is still in its infancy and I'm not going over what I've already said except to try and put it into some perspective.

            In quick attempt to do this, consider for a moment the remarkable 100-year old photos by Lewis Wickes Hine (at end of post), H&S issues are self-evident. Here, H&S is about as bad as it gets (with the photographic record), and I emphasise both the 'H' and the 'S'. These photographic examples are not isolates cases, it is just how it was back then (unless you were rich).

            I often use them as a starting point when discussing H&S issues. Why you may ask, well there's many issues involved--far too many to go into here--but I'll mention one. Despite the atrocious appalling conditions these kids worked in, one thing stands out above almost everything else--as a group it's the remarkable tenacity, stamina and resilience they had. As said, these are not isolated instances, there's 5000 or so photos, documented histories etc. which have been analysed to support the case. (Quick DIY check: in the thousands of prints it's almost impossible to find a dejected kid, given his job that would have desirable.)

            Today, especially in the English-speaking word, that level of tenacity and resilience has all but gone. We protect kids at school, from mercury and other chemicals, the cane, bullying, sexual predators, whatever.... Driving kids to school is now taken for granted (certainly wasn't so 40 years ago). Now, there are well-documented cases of kids that have been so sheltered and protected that they're actually scared to go out into the street by themselves (and this is only the tip of the iceberg).

            I'm not saying for one instant that protecting kids from the examples I've just given is bad, rather it's the degree and methodology. H&S legalisation as it's currently written and practiced is having the same effect, and what is driving the legislation is an increasingly timid and scared society (that surveillance is almost out of control may not be proof but it's damn close). Any astute observer over 40 can attest to this, and it's glaringly obvious to those a decade or two who older. Obviously, I've not time to go into the reasons, studies etc. here but there's reasonable literature on the subject (but I will mention the incessant sensory overload from 'bad' media stories being a part of it).

            In summary, H&S and other protective legislation has come a long way since the turn of the 20th C., conditions have improved enormously for the better, but in the last 35 or so years there's considerable and growing evidence that the consequences for society are becoming seriously problematic.

            Bletchley Park and its mercury delay line problem is just another practical instance of where the issues surface.

            L.W.Hine's photos (ca 1908-14):

            http://www.loc.gov/pictures/collection/nclc/item/ncl2004000870/PP/

            http://www.loc.gov/pictures/collection/nclc/item/ncl2004000217/PP/

            http://www.loc.gov/pictures/collection/nclc/item/ncl2004000227/PP/

            http://www.loc.gov/pictures/collection/nclc/item/ncl2004001107/PP/

    2. Ian Stephenson
      Coat

      The argument could be made that...

      Health and safety will lead to the extinction of the human race by preventing natural selection (the terminally stupid removing themselves from the gene pool) occuring and thus trapping us in an evoltuionary dead end.

      That's mine... the one with no UVB protection or kevlar inserts.

  2. Anonymous John

    No mercury?

    If it's good enough for Curly Flickering Lights, it's good enough for a compter.

  3. Paul_Murphy

    Good luck guys (and girls of course).

    After visiting BP for the first time this year and seeing the amount of effort put into the Colossus re-build, not to mention the bombe rebuild as well, I'm sure that they will do an excellent job and hopefully visitors will be able to follow their progress once things start to get viewable.

    There is still the question of what they might intend to do with it once it's done, but the journey will be interesting.

    ttfn

    1. Anonymous Coward
      Thumb Up

      No doubt..

      Port a twitter app. That seems to be the rage at the moment.

  4. Anonymous Coward
    Go

    Going to be faster...

    than any modern machine running vista.

  5. JaitcH
    Unhappy

    Imagine the power bill for this monster ... Ouch!

    Will it require a 2-phase or 3-phase supply?

    At least building heating concerns will be covered but how about the air-con?

    1. Tom 7

      Air Con?

      Thermionic devices don't need aircon. Its the wimps around them that like to pretend they need it.

      At Bletchly they stripped down in the heat. Half naked ladies didnt worry Turing!

  6. eJ2095

    BP

    Had a fab day there last sept with my friend.

    We was even allowed behind the scenes to take some infra red pics of Colossus.

    Chatting to staff in the back rooms..

    (Then for fun basterdising the acorn arc they have on display with a simple basic program lol)

  7. Wyrdness

    Did Turing solve this?

    Accoring to Wikipedia, Alan Turing proposed using gin instead of mercury, claiming that it had the necessary acoustic properties. The team at Bletchley should certainly investigate this option and I'd be very happy to volunteer my services, a bottle of tonic and a few lemons towards this important research.

  8. Mage Silver badge

    Mercury?

    It's not a consumer product, so mercury delay lines are feasible.

  9. Mage Silver badge

    TVs

    TV uses glass (or quartz) as 64uS delay line.

  10. Anonymous Coward
    Anonymous Coward

    Racetrack Memory

    If mercury can't be used, why not go for the contrast of something conceptually similar but ultra modern like Racetrack Memory?

    1. hplasm
      WTF?

      And why not

      add a modern CPU, like an Atom or something, to save power?

  11. Anonymous Coward
    Happy

    A suitable "delay line" memory replacement.

    An old analogue guitar echo unit. Preferable a tape-loop-based one (echoplex, wem copicat) but one based on a bucket-brigade delay line would do too.

    1. Purple People Eater

      RE: A suitable "delay line" memory replacement

      Definitely a wire-based unit - that's REAL solid state memory!

  12. Graham Bartlett

    Future of computing

    "broke new ground by enabling the catering company J Lyons & Co Ltd to perform payroll calculations"

    Bet the designers were chuffed with that. Build them a world-class supercomputer, and what do they use it for? Gene research? Crystallography? Nope, it's making Excel spreadsheets run faster...

    1. Anonymous Coward
      Anonymous Coward

      It's worse than you think

      The whole mainframe computer industry was built on outperforming payroll clerks with their ready reckoners. Ever wondered how IBM got its name?

  13. Tom 7

    Can they open source the software

    cant seem to find any proprietary software that's as good as Leo was ...

  14. Anonymous Coward
    Anonymous Coward

    Manchester

    Why not the Manchester Baby? It predated EDSAC by a year and also inspired the early commercial machines.

    http://en.wikipedia.org/wiki/Manchester_Small-Scale_Experimental_Machine

    1. Phil Endecott

      Re: Manchester

      > Why not the Manchester Baby?

      Because that's already been done. Years ago.

    2. Hugh McIntyre

      Re: Manchester

      Some people already built a replica of the Manchester Baby for the 50th anniversary in 1998, so that's already done. It's apparently in the Manchester Museum of Science and Industry - see http://www.cs.manchester.ac.uk/Digital60/Baby/.

      Incidentally, for anyone in Silicon Valley, the Computer History Museum just opened a "first 2000 years of computing" exhibit which, along with abacuses, mechanical calculators, and newer computers, has a video of the Baby, Colossus, and the Leo amongst other computers. And things like ENIAC as well, for example.

      It also has a coiled-wire delay line used by an early Ferranti computer which might be a better alternative to mercury.

      1. Graham Wilson
        Boffin

        @Hugh McIntyre -- Delay lines aren't the point, but authenticity is.

        Delay lines aren't the point as there's any number of types nowadays. If you want high bandwidth then use fibre optic cable wound on a drum, medium bandwidth as in television--use 75 ohm coax or a glass delay line (a la TV sets), low B/W then use mercury or whatever has the right acoustic properties.

        BUT THIS IS NOT THE POINT (AND THE REASON FOR ALL THIS DISCUSSION), WHICH IS THAT BY NOT USING A CRUCIAL PART (THE DELAY LINE) WHICH IS MADE IN THE SAME WAY AND THAT ALSO WILL FUNCTION IN THE SAME WAY THEN YOU UNDERMINE THE INTEGRITY OF THE PROJECT.

        CHANGING THE MODUS OPERANDI OF THE DELAY LINE (I.E.: GOING TO ANOTHER TYPE) DESTROYS BOTH HISTORICAL AND FUNCTIONAL INTEGRITY. IT IS NO LONGER A CLONE OF THE ORIGINAL BUT SOMETHING ELSE.

  15. PowerSurge
    Boffin

    I remember EDSAC

    Dad used to take me to see it when I was a lad. It had a floor-ceiling central column of valves, like a 7 sided octagon with the 8th side open. You could walk in and have access to all the valves, for easy changing. No doubt ventilation was an important function of the column too.

    My main interest was the big tape drives. I guess it was two inch tape on reels much like multitrack audio tape. The reels were side-by-side on decks which sloped back at 30 deg and had glass covers over them. They jerked backwards and forwards in a curious unpredictable way. Learning that these were about to be scrapped I fancied one would fit nicely in our sitting room. Dad didn't buy into that.

    My understanding, which may have been wishful thinking, was that it was the first 'electronic' computer. Earlier ones used relays and the like.

    1. This post has been deleted by its author

  16. Fading
    Coat

    But will it play Crysis?

    Got to love the 650 instructions per second performance stats. Still given 650 ips = 0.00065 MIPS then the PC I'm typing this on is only 7.56x10^7 times more powerful (theoretically) .

    Though given as the OS is windows the actual performance difference is probably less.

  17. twelvebore
    Coat

    I want to know...

    ...how this mother is gonna overclock. Are they shooting for the 10Hz record?

  18. Anonymous Coward
    FAIL

    Oh! What a surprise.

    Another waste of time and money in a nation of people who seem incapable of doing anything but living in the past, be it revelling in the intelligence and creativity of their forebears, or apologising for the acts of their forebears.

    1. Graham Wilson
      Big Brother

      @ A. Coward -- It's probably just as well that you are anonymous.

      It's probably just as well that you are anonymous, otherwise we might put you in the stocks or pillories for all of Saturday.

  19. Graham Wilson
    Flame

    The paranoia over the dangers of mercury is now out of hand.

    The paranoia over the dangers of mercury is now out of hand. That it can't be used at Bletchley Park to recreate something as special as the storage delay simply borders on the hysterically absurd. Even if the new bogeyman is mercury, there's no reason why special precautions and enclosures cannot be used to make it environmentally acceptable. It seems to me there's very little point in recreating this computer if this not authentic. Why bother at all? May as well make it out of plasticine if it isn't done correctly.

    In the lax days of a few decades ago when there was almost no regulation over mercury, it was used in large quantities in industry and one rarely heard of anyone getting mercury poisoning. If you walked into a railway rectifier room of about 40 years ago, you'd see gallons of it inside huge mercury-arc rectifiers all glowing with an eerie violet glow. One never heard of utter disaster when one broke (which they occasionally did). Whenever I entered a Hg-arc room (an occasional experience), I was always much more concerned about the high voltage than being poisoned by the Hg.

    Sure, this element in metallic form can be dangerous if not handled correctly but handling it is now well understood. Moreover, professions that were reckless with it had long since gone by the end of the 19th C. (Making Daguerreotype photos whilst breathing volatile Hg fumes, or being a 'mad' hatter and curing pelts with Hg were professions seemingly devoid of even the most elementary precautions.)

    Metallic mercury isn't that dangerous if handled with care, and I've a mouthful of mercury amalgam fillings to prove it, some of which I've had for many decades--yet I'm still sufficiently compos mentis to write this. ;-) Remember too, if you'd caught syphilis before the War then you'd have little choice other than to ingest mercury. With luck, and if you'd successfully managed the thin line between Hg OD and an insufficient amount, then it might have eventually cured you.

    Mercury is still used in the form of thimerosal as a preservative for vaccines; we think its toxicity is sufficiently low that its use outweighs the perishing of vaccines. Until recently, the antiseptic Mercurochrome was commonly available (and I still have a bottle of it).

    When I was at high school, we had large jars of mercury and one of the most memorable experiments was to try and push one's hand to the bottom of the jar (Hg about 10cm deep). It's is quite a challenge I can assure you. (We did it outside and scrubbing with soap afterwards was the order of the day.)

    That said, some organic compounds of mercury are very dangerous, specifically the (mono) methylmercury cation, CH3Hg+, and its very nasty and extremely toxic brother, dimethylmercury (CH3)2Hg. Monomethylmercury+ is of concern because in this organic form it can enter the food chain and become a cumulative neurotoxin. This happened about 50 years ago in Minamata Bay in Japan with horrific consequences for the local fish-eating population. The Hg entered the bay as effluent in the CH3Hg form 'dumped' by an irresponsible industry.

    (BTW, Those whose chemistry has not deserted them completely will know that if you're using metallic mercury in some industrial process it won't suddenly start producing organic forms and become super toxic (unless that process is a specialised chemical one). If you're careless, you might suffer the effects of the metallic mercury, but in the event you were tested and found to ALSO have traces of CH3Hg in your system then it almost certainly won't have come from your exposure to the metallic form. Almost certainly, it'll have come from top-predator fish that you've been eating. Outside the lab, CH3Hg is usually produced when microbes convert metallic Hg to the very dangerous organic form which fish accumulate.)

    Perhaps I've written an overly long rave but I've done so because I'm becoming increasingly concerned about how timid and overprotected our society has become in recent years. Not only are we producing a society full of people who are terrified of anything 'chemical' but also the hands-off approach to chemicals is deskilling the nation. I now know people who have never seen liquid mercury in their life, and who are terrified of the thought of coming across any. Ban it from schools and this is what happens. It's tragic really, it's no wonder Asia, without such hang-ups, is wiping the floor with us.

    We never seem to get regulations with the correct balance. With respect to hazardous chemicals, we've gone from having almost no regulations 50 years ago to the other extreme where we can't even use mercury in this historic Bletchley Park computer. It's just crazy, much of the blame has to be leveled at the damn postmodernists who infiltrated our education system some 20/30 years ago and subverted it with anti-science rhetoric. Now we've a large core of the population who are deeply suspicions of science.

    Finally, my position is not for tight but rather sophisticated regulation. For instance, I'd greatly tighten the regulations for handling mercury in schools than from the time when I was there but in no way would I ban it. Otherwise, how else are kids ever going to get experience when there's nothing to get hands-on experience with.

    [Oh, BTW, at school we even had samples of metallic uranium and its ore as well as alpha and beta radioactive sources that we used for proper hands-on experiments (such as the different blocking properties of various materials when exposed to alpha particles). Being the school's electronic nerd, I even built my own Geiger-Müller counter. If I hadn't had access to these radioactive sources then there's no way I would have tackled such a project. At 14, it felt like a great achievement. For kids, hands-on, messy, noisy science is essential; theory is just not sufficient.]

    1. Vladimir Plouzhnikov

      Dangers of mercury

      "yet I'm still sufficiently compos mentis to write this"

      Er, but how do you know? :-)

      1. Graham Wilson
        Boffin

        @Vladimir Plouzhnikov - In absolute terms, I don't; in relative ones I think I am.

        Good question.

        In absolute terms, I don't. Nor is it logically deducible.

        In relative terms I can make few deductions. The line of argument goes this way: (a) all my posts to this El Reg thread were read by the moderator and passed for posting, (b) a few thumbs-up and replies indicates what I was saying was interpretable. Cognizance has transpired. Whilst this helps me to answer, you've still no way of knowing that I'm not actually an automaton.

        Whether the total level of Hg traces I've consumed over my lifetime has changed my IQ also is moot. The same could be said for elements Pb, Cd, Se, Be, and Cr (known small exposures to these) not to mention other toxic chemicals, PCBs vinyls etc. It's possible but to my own perception is that it would be small.

        Of course, the best analysis would be better done by you (based on what I've written (but that doesn't help if you wanted my status 20 years ago.

        But I do know it's midnight here and neurons are dropping off, concomitantly so is my cognizance.

        >:-)

  20. Big-nosed Pengie
    Thumb Up

    Brilliant!

    Had the pleasure of visiting BP and seeing the Colussus rebuild. What an amazing pack if geniuses those people are!

    1. Graham Wilson
      Happy

      @Big-nosed Pengie - Thanks

      Thanks.

      Not seen Colussus yet but read much of the literature (although visiting is on my agenda).

      BTW, above, @Ian Yates I've expanded on my views.

  21. Steve Hosgood
    Thumb Up

    Good for you, Graham Wilson

    ...you just saved me writing the same rant!

    Basically, if the rebuild doesn't use mercury delay lines, then it isn't a rebuild. It's "just another valve computer".

    We all have thermometers in our homes, and florescent lamps everywhere. All contain mercury. No one dies as a result. Mercury != high level nuclear waste. Get over it. Take care, yes, but it is safe to use.

    1. Graham Wilson
      Alien

      @Steve Hosgood -- Precisely correct! And cop this scenario.

      ...And don't start me on the 'Green Compact Fluorescent' problem. If you haven't heard of it, it goes like this. Some brands of compact fluorescents are now been sold as being 'greener' models as they contain less mercury than standard units.

      Right, the light flashes on to even the dumbest of us (or so you'd think):

      -- less Hg means that many globes are now failing in under 1000 hours--a standards incandescent's life (anecdotal info -- drop Hg by 50%, globe life drops 8k to 1k hours--i.e.: Hg amount/globe life is not linear),

      -- yet they've a birth/manufacture/death energy requirement that's much higher than an incandescent,

      -- and the manufactures can't believe their luck: less mercury, less cost per unit--as it's the only ingredient that no one will or has the guts to say that consumers have been short-changed on by actually receiving less,

      -- thus less mercury automatically means more bulb sales (specifically as the nominal 8000 hours has now fallen to fewer than 1000 hours--AND it really doesn't matter doesn't matter (after all, globes now have less mercury) ;-)

      -- NOR DOES IT MATTER that the TOTAL Hg in the environment has actually gone up (life - 8k drop to 1k, but say only 50% Hg drop per unit ==> net overall increase of Hg used.

      Yet no one says anything (consumer groups, IEEE, engineers, electricians' bodies et al. Deadly silence from everyone--even Greenies.

      The hypocrisy just staggers me.

      Truly incredible!

  22. JayBS
    Boffin

    Hg Delay line: 'ow it worked

    http://www.allaboutcircuits.com/vol_4/chpt_15/4.html

    NB The banning of lead in solder is another example of EU over-reaction IMHO. The likely consequences ( higher failure-rates in electronic products) represent a possible ticking bomb.

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