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The World's Oldest Original Digital Computer Springs Back Into Action At TNMOC

New submitter prpplague writes "After a three-year restoration project at The National Museum of Computing, the Harwell Dekatron (aka WITCH) computer will rebooted on 20 November 2012 to become the world's oldest original working digital computer. Now in its seventh decade and in its fifth home, the computer with its flashing lights and clattering printers and readers provides an awe-inspiring display for visiting school groups and the general public keen to learn about our rich computer heritage."

65 comments

  1. Bletchley Park, amazing place. by Anonymous Coward · · Score: 4, Informative

    I highly recommend visiting bletchley park. You won't be disappointed.

    1. Re:Bletchley Park, amazing place. by ciderbrew · · Score: 1

      Now got one of my gifts from Santa sorted. Thanks.

    2. Re:Bletchley Park, amazing place. by Anonymous Coward · · Score: 0

      Second that. Abso-freaking-lutely amazing.

  2. Not a digital computer by Anonymous Coward · · Score: 0, Interesting

    With 828 dekaton counter tubes I reckon it's not a digital computer (2 base) but a decimal computer (10 base).

    There are 10 kinds of people who understand binary...

    1. Re:Not a digital computer by Chrisq · · Score: 5, Informative

      With 828 dekaton counter tubes I reckon it's not a digital computer (2 base) but a decimal computer (10 base).

      There are 10 kinds of people who understand binary...

      It is still a digital computer (as opposed to an analogue computer), as were other non-binary false starts like the Setun which used balanced ternary.

    2. Re:Not a digital computer by Anonymous Coward · · Score: 5, Informative

      And yet even more people who have problems with English.
      Digital, as opposed to analogue, refers to the data being in discrete chunks.
      You may be correct in it being a decimal computer, as opposed to a binary computer, but it is still a digital computer.
      However the Dekatron valves could be made in effective binary mode (9 anodes to 1 pin) so it could still be a binary computer.

    3. Re:Not a digital computer by expatriot · · Score: 4, Informative

      You do know that the term "digital" comes from "finger" so the origin is closer to base 10 than 2. The modern definition is something quantified by numbers rather than continuous properties. A digital encoding of 0.5 volts as the number 0.5.

      This does lead on to the adage that "end the end, everything is analogue" which makes more sense if you have ever used a high-frequency storage oscilloscope.

    4. Re:Not a digital computer by Sique · · Score: 5, Informative

      "digital" comes from "digit" (number), which in turn comes from the latin "digitus" (finger). It has nothing to do with binary, other than binary being digital too. Any number based computer is digital. There are analog computers which use continuous currents or voltages to calculate. Those are not digital.

      --
      .sig: Sique *sigh*
    5. Re:Not a digital computer by Chrisq · · Score: 4, Informative

      And yet even more people who have problems with English. Digital, as opposed to analogue, refers to the data being in discrete chunks. You may be correct in it being a decimal computer, as opposed to a binary computer, but it is still a digital computer. However the Dekatron valves could be made in effective binary mode (9 anodes to 1 pin) so it could still be a binary computer.

      It was most definitely a decimal computer.

    6. Re:Not a digital computer by Formalin · · Score: 2

      However the Dekatron valves could be made in effective binary mode (9 anodes to 1 pin) so it could still be a binary computer.

      That wasn't for binary, it was for allowing less complicated tubes if they were only going to be used as divide-by-10. Instead of drawing out all 10 cathodes, cathode 0 has it's own pin, and 1-9 are on a common pin... as you only need to measure / know when cathode 0 goes high again (signifying 10 pulses have occurred).

      If they only needed binary it would be a flip flop instead (either tube, for 'high' speed, sometimes glow lamps in slower things)

      but yeah, absolutely digital.

    7. Re:Not a digital computer by Anonymous Coward · · Score: 1

      No, there are 3 types of people in the world: those who can count, and those who can't.

    8. Re:Not a digital computer by Chrisq · · Score: 1

      No, there are 3 types of people in the world: those who can count, and those who can't.

      Or, there are 1T types of people in the world. Those who understand balanced ternary and those who don't.
      or: There are 110 types of people in the world. Those who understand negabinary and those who don't.

    9. Re:Not a digital computer by mcgrew · · Score: 2

      I was going to post an amusing personal coincidence from wikipedia: "the machine became operational in April 1951. It was handed over to the computing group in May 1952."

      It's exactly one year older than me; I was born in April 1952. Whoever did the summary isn't very good at math, I'm not 70 years old. This thing was operational 61 years ago. Most of you guys grew up with computers, Computers grew up with me.

      It is still a digital computer (as opposed to an analogue computer), as were other non-binary false starts like the Setun which used balanced ternary.

      Yes, a base 3 computer would use positive, negative, and off. Seems like one would be a lot more complex to design than a binary computer.

      They also had pure analog computers well into the 1960s (maybe even '70s) that used voltage as a "number system". Most were vaccuum tube based. No rounding errors, but noise was the problem.

    10. Re:Not a digital computer by sdoca · · Score: 1

      You may not be 70, but you are in your seventh decade. You were in your first decade of life from age 0 to 9.

  3. THAT IS THE ONE ANDY GROVE DESIGNED !! by Anonymous Coward · · Score: 1

    Around the time when dinosaurs ruled the planet !!

  4. 1951? by Anonymous Coward · · Score: 0

    That's impossible. I've been assured many times that we only have computers because we went into space. Sputnik was 1957, so clearly, this can't be. Unless... Maybe... People invent things anyways and we went in to space AFTER we had all the technology necessary?

    1. Re:1951? by Anonymous Coward · · Score: 0

      You've got to be taking the piss. Never heard of Colossus?

      http://en.wikipedia.org/wiki/Colossus_computer

      "Colossus was the world's first electronic, digital, computer that was at all programmable."

      1943

    2. Re:1951? by SleazyRidr · · Score: 1

      Yes, the world is every bit as simple as you were lead to believe in grade school. Computers were created just as they are now in 1943, and no potential or intended uses for them have altered their development in any way.

    3. Re:1951? by SomePgmr · · Score: 1

      It's unlikely anyone has ever told you that computers were invented for space travel.

      What they probably told you is you enjoy technological advances spurred by the space program, evidenced by things you take for granted in your everyday life, such as your computer and mobile phone. And that's accurate in that the space program helped drastically advance the miniaturization of electronics and improvements in material sciences, among countless other things.

  5. "will rebooted": it is self-aware! by fgrieu · · Score: 2

    If this computer can decide to reboot itself, it must have now reached self-awareness!

    1. Re:"will rebooted": it is self-aware! by ericloewe · · Score: 1

      So I guess the NT Kernel is self-aware. Same goes for Linux, I presume.
      Cue Apple marketing OS X crashes as it being self-aware and magically resetting itself to a safe state.

  6. But why? by aglider · · Score: 1

    Restoring computing machinery for a show in a museum is one thing, making it working again is a real waste of resources!

    --
    Sent as ripples into the electromagnetic field. No single photon has been harmed in the process.
    1. Re:But why? by Anonymous Coward · · Score: 1

      So Comrade, when did you become the chairman of the Computer Restoration Central Planing Bureau?

    2. Re:But why? by aglider · · Score: 1

      ... just a few weeks! How is your business with old-tubes factory?

      --
      Sent as ripples into the electromagnetic field. No single photon has been harmed in the process.
    3. Re:But why? by ciderbrew · · Score: 1, Troll

      Facebook is waste of resources. This shows people that take things granted the hard work people put in to allow Facebook to even work.

    4. Re:But why? by LoRdTAW · · Score: 1

      "But Why?"

      Why not?

    5. Re:But why? by crazyjj · · Score: 1

      making it working again is a real waste of resources!

      Do you realize how many programmers spend every day designing games for Facebook, new fart apps for iOS, and expansions for WoW?

      --
      What political party do you join when you don't like Bible-thumpers *or* hippies?
    6. Re:But why? by mcgrew · · Score: 1

      Slashdot, please stop giving mod points to non-nerds! Facebook is NOT a nerd site, and trashing it isn't trolling. The GP is the fucking troll and can't possibly be a nerd. "Restoring computing machinery for a show in a museum is one thing, making it working again is a real waste of resources!" should have been modded to oblivion. It's incredibly inflammatory to we nerds, unlike "facebook is a waste of resources." That's only inflammatory to teenagers and middle aged mothers. Sheesh...

    7. Re:But why? by Taxman415a · · Score: 1

      Something can be interesting, but still not worth the resources. For example, it may be interesting to grind away all of the earth's crust and send it into the sun, but that doesn't mean it's worth it. Everything has tradeoffs and the smarter thing to do is to think for a bit about those tradeoffs rather than knee jerk responding that it's interesting therefore it must be done, damn the cost. Maybe the same resources could be put to a more valuable and interesting use while 95% of the learning and interest value could be gotten out of this project without expending so many resources. Maybe not, but it's probably worth considering.

  7. Nice... by Anonymous Coward · · Score: 3, Funny

    ...But does it run Linux?

  8. That's a real computer by Anonymous Coward · · Score: 2, Funny

    Imagine a Beowulf cluster of those!

    1. Re:That's a real computer by Sponge+Bath · · Score: 1

      No wireless, less space than a Nomad. Lame.

  9. 828 flashing Dekatron valves by dtmos · · Score: 3, Informative

    Dekatron valves are an example of a solution to the problem of making storage registers before integrated circuits made them essentially free. Making reliable working memory was one of the biggest problems faced by the early computer hardware designers, and Dekatron valves (tubes) were one of the more creative solutions. Of course, the reliability of solid-state electronics made them a technological backwater, but that makes them no less interesting -- it's fun to speculate on how things would have worked out if cold-cathode valves remained the dominant storage technology.

    1. Re:828 flashing Dekatron valves by cbhacking · · Score: 1

      it's fun to speculate on how things would have worked out if cold-cathode valves remained the dominant storage technology

      Well, for one thing, you probably wouldn't be reading this site. Just downloading this webpage takes more resources than a lot of those early computers had, never mind rendering it. Valve-based systems don't scale it a way even remotely close to Moore's Law, and their lack of reliability meant that making the machine with too many of them just meant shorter mean time between failure and more time and expense spent on maintenance. The Internet as we think of it today would probably never have existed, much less reached anything close to its current scale. Too expensive, too little utility for the number of nodes that could be connected to it. There would have been a network of some kind, and by now it probably would have spread to home units (though certainly not to anything like smartphones), but it would have simple and low-bandwidth, designed for consuming information rather than communicating. Think gopher more than the web, and newspapers (which might include a personal ads section) rather than Skype.

      --
      There's no place I could be, since I've found Serenity...
    2. Re:828 flashing Dekatron valves by ciderbrew · · Score: 1

      But it would look at steam punk and have a wonderful orange glow!

    3. Re:828 flashing Dekatron valves by Gordonjcp · · Score: 1

      Round about the time the WITCH was current, it looked like transistor-based systems wouldn't scale either. It's all down to which way you apply technology.

    4. Re:828 flashing Dekatron valves by Formalin · · Score: 1

      Tube logic was inefficient, and had reliability issues due to short life, but they were capable of high (MHz) switching speeds. Of course the size of things raises problems, and you have to run it a lot slower than any given gate could run, I suppose. Line driving issues, stray capacitance in the miles of wiring and whatnot, will kill your sharp edges and miss pulses.

      Cold cathode, however, was slow as fuck. A couple kHz, maybe, for neon; somewhat faster for argon. Hydrogen was the fastest IIRC ( the small size must (de)ionize faster - must why they used it in high speed thyratrons for pulsed radar and whatnot also?), but still in the kHz range.

    5. Re:828 flashing Dekatron valves by mcgrew · · Score: 1

      Well, for one thing, you probably wouldn't be reading this site

      You wouldn't be reading this site without integrated circuits. When I was in the USAF in 1972 I got to see the insides of a 1972 computer that ran a C-5A flight simulator. Rooms full of bookshelves, except instead of books the shelves held printed circuit boards. That was a computer in 1972, and it was probably far less powerful than an Apple IIe.

  10. When the lights dim in the building... by Anonymous Coward · · Score: 0

    ...you shall know that it has been turned on.

    1. Re:When the lights dim in the building... by HybridST · · Score: 3, Interesting

      Copypasta from TFA:
      Power Consumption: 1.5kW
      Size 2m high x 6m wide x 1m deep
      Weight: 2.5 tonnes
      Number of Dekaton counter tubes: 828
      Number of other valves: 131
      Number of relays: 480
      Number of contacts or relay switches: 7073
      Number of high speed relays: 26
      Number of lamps: 199
      Number of switches: 18

      It uses about the same power as the space heater in my living room which does dim the lights across the apartment. I'd expect a museum to have slightly better power than the century-home I live in although I may be mistaken on that point.

      --
      Ever notice that Cobra Commander sounds an awful lot like Star scream?
    2. Re:When the lights dim in the building... by Anonymous Coward · · Score: 0

      Power Consumption: 1.5kW

      So this computer is in the UK. A standard socket (power outlet) is capable of delivering a maximum of 13A at 230V, which is just a touch under 3kW. The WITCH uses less than a standard British electric kettle.

      Even allowing for you being in the United States, if a 1.5kW appliance causes your lights to dim, I'd call an electrician.

    3. Re:When the lights dim in the building... by Formalin · · Score: 1

      Neato. I'd have (rather uneducated-ly) guessed at least an order of magnitude more power consumption.

    4. Re:When the lights dim in the building... by ericloewe · · Score: 1

      The really interesting part is that high-end (and I mean high-end - multiple GPUs for instance) systems still use about that much power.

  11. Correction by wonkey_monkey · · Score: 1

    It's the oldest working digital computer.

    This is what you get when submitters copy-and-paste everything.

    New submitter prpplague writes

    Can we get rid of this standard introduction? It's almost never true.

    --
    systemd is Roko's Basilisk.
  12. Indeed by Anonymous Coward · · Score: 0

    Please tell me that was a simple typo, rather than a professional writer who skipped too many English classes.

  13. Pity it was not ready for 31 October by Alain+Williams · · Score: 1

    With a name like that an announcement on Halloween would have been fun.

  14. Car analogy by loufoque · · Score: 2

    That's like saying "this car does not run on petrol, it has 6 wheels".

  15. The second oldest digital computer is on the bend. by 140Mandak262Jamuna · · Score: 3, Funny

    Before this Dekatron came back to life, the title of being the oldest working digital computer was held by NS1978. On hearing that it lost that coveted title, it got despondent, got drunk and was seen stumbling through traffic on the Jersey Turnpike, screaming out what time each driver will get home.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  16. Don't forget the ABC... by MobilePowerGuy · · Score: 1

    It would be remiss to ignore the Atanasoff-Berry Computer (1942). It predated Harwell (and ENIAC). http://en.wikipedia.org/wiki/Atanasoff%E2%80%93Berry_Computer

    1. Re:Don't forget the ABC... by nozzo · · Score: 1

      also the Z1 - the first programmable computer (albeit quite limited) http://en.wikipedia.org/wiki/Z1_(computer)

    2. Re:Don't forget the ABC... by Anonymous Coward · · Score: 0

      Except the ABC isn't a) a computer b) functional.

    3. Re:Don't forget the ABC... by mcgrew · · Score: 1

      It would be remiss to ignore the Atanasoff-Berry Computer (1942).

      I wouldn't call a calculating machine that couldn't be programmed a "computer." Yes, it was a forerunner to computers, and technical developments for it were used in computers, but I wouldn't call a non-programmable device a computer.

  17. Mayan Predictions by retech · · Score: 1

    The WITCH going live right before the end of the world prediction... coincidence? I think not.

  18. worth seeing by nozzo · · Score: 1

    During a short spell volunteering for TNMOC I watched this being worked on. Truly a labour of love and a great achievement and some amazing talented people involved in the project. most definitely worth a visit.

    1. Re:worth seeing by Anonymous Coward · · Score: 0

      Can I play one-up?

      I used this computer when I was on Computer Science course at Wolverhampton in 1967. It was part of the syllabus. :)

  19. Don't forget the Zuse Z3... by gnasher719 · · Score: 1

    Completed in 1941.

    1. Re:Don't forget the Zuse Z3... by Chris+Mattern · · Score: 1

      ...which was destroyed in an Allied bomb raid in 1943. Yes, a duplicate was built in the 1960s which is still operational today, but it doesn't stop the WITCH from becoming the oldest *original* still-operating computer in existence.

  20. Oblig... by Anonymous Coward · · Score: 0

    Yes, but will it run Crysis?
    Imagine a Beowulf cluster

  21. Rebooted? by MDMurphy · · Score: 1

    I can only guess that the author of the article thinks that "rebooted" means "plugged in and turned on". When I first saw the title I thought it meant that it had been running for years and was to undergo a rare re-start.

  22. Thankfully it wasn't invented in Birmingham. by TheSkepticalOptimist · · Score: 1

    Lets see how long this one takes.

    --
    I haven't thought of anything clever to put here, but then again most of you haven't either.
  23. oldest original digital computer? by MouseTheLuckyDog · · Score: 1

    You mean there is a newer original digital computer?

    1. Re:oldest original digital computer? by prpplague · · Score: 1

      there are replicas of older digital computers such as the Colossus(http://en.wikipedia.org/wiki/Colossus_computer), but they are not the original. The Harwell Computer is all of the original equipment....

  24. It passed the Y2K test. by Anonymous Coward · · Score: 0

    Good old sparky.

  25. Imagine by jandersen · · Score: 1

    ... a Beowulf cluster ...