The Case Of The Vintage Computer, The Blown Fuse, And The Diode

If you are the operator of a vintage computer, probably the only one of its type remaining in service, probably the worst thing you can hear is a loud pop followed by your machine abruptly powering down. That’s what happened to the Elliott 803B in the UK’s National Museum Of Computing, and its maintainer [Peter Onion] has written an account of his getting it back online.

The Elliott is a large machine from the early 1960s, and because mains supplies in those days could be unreliable it has a rudimentary UPS to keep it going during a brownout. A hefty Ni-Cd battery is permanently hooked up to a charger that also serves as the power supply for the machine, ensuring that it can continue to operate for a short while as the voltage drops. A spate of fuses had blown in this power supply, so we’re taken through the process of fault-finding. Eventually the failure is found in a rectifier diode, the closest modern equivalent is substituted, and after testing the machine comes back to life.

We’re used to reading these stories from the other side of the Atlantic, so we welcome TNMOC saying that this is the first of a series of technical posts on their work. We visited the museum back in 2016, and also featured its famous recreated Colossus.

How Hard Can It Be To Buy A Computer In Germany And Get It Back Home To The UK?

Some of the best adventures in the world of hardware hacking start in the pub. For three volunteers at the National Museum Of Computing in the UK, [Adam Bradley], [Chris Blackburn], and [Peter Vaughan], theirs started over a pint with an eBay listing for an old computer in Germany. No problem you might think, we’re well used to international parcel shipping. This computer wasn’t a crusty old Commodore 64 though, instead it was a room-sized IBM System/360 Model 20 from the 1960s, complete with the full array of peripherals and what seemed to be a lot of documentation and software media. It would need a Mercedes Sprinter, a large van, to shift it, but that seemed feasible. With a bit of frantic bidding they secured the auction, and set off for Germany to view their purchase.

Arriving at the machine’s location they found a little bit more than they had expected. In an abandoned building on a side street in Nuremburg there was an intact machine room full of the IBM computer cabinets over a false floor with all the machine cabling in place, and the only usable access was through a street door which hadn’t been opened in decades and which was obstructed by the false floor itself. To cap it all they found they’d bought not one but two System/360s, and also unexpectedly a 1970s System/370 Model 125. Clearly this was more than a job for a quick in-and-out with a Sprinter.

What followed became a lengthy saga of repeated trips, van hire, constructing ramps, and moving heavy computer parts to a hastily rented storage unit. Decabling a computer of this size is no easy task at the best of times, and these cables had spent many decades in a neglected machine room. It’s a fascinating read, and a very well-documented one with plenty of photos. The machines now sit in their storage units awaiting a return to the UK, and the trio are soliciting any help they can find to make that happen. So if you happen to own a European haulage company with spare capacity on your Germany — UK route or if you can help them in any way, donate or get in touch with them. We think this project has much more to offer, so we’ll be following their progress with interest.

These three intrepid computer hunters were brought together at The National Museum Of Computing at Bletchley, UK. If you find yourself within range it is an essential place to visit, we did so in 2016.

Help Keep The Bombe At Bletchley

Fans of vintage codebreaking machinery might be interested to hear that the only working reconstruction of a Turing-Welchman Bombe is likely to soon be on the move. The electromechanical device, a replica of those used on the Second World War Enigma codes, is housed at Bletchley Park, the former codebreaking center established before the outbreak of war to house British and Polish codebreakers.

Bletchley Park itself is now a tourist attraction. The news is that a display reorganization has caused the Turing Welchman Bombe Rebuild Trust that owns the Bombe to approach the neighboring National Museum Of Computing with a view to housing it alongside their reconstruction of the Colossus electronic computer. The Colossus was famously used on the Lorenz cipher. This is an exciting development for the museum, but as an organization reliant on donations they face the task of finding the resources to create a new gallery for the arrival. To that end, they have launched a crowdfunding campaign with a target of £50000 ($69358.50), and they need your donations to it for the project to succeed. They have raised over £4500 in the few days it has already been open and there is most of a month still to go, so we hope they achieve their goal.

The Bletchley Park site is now surrounded by the post-war new town of Milton Keynes, and is easy enough to get to should you find yourself in the UK. We visited The National Museum Of Computing a couple of years ago and spent a very happy day touring its extensive and fascinating collection. If you want to read more about the Bombe you might like to read our review, and also our impression of Colossus.

As part of their campaign, the museum has produced a promotional video, which we have placed after the break.

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Review: The National Museum Of Computing

Here’s a question for you all: how will you know when you are no longer young? When you fall out of love with contemporary popular music perhaps, or start to find the idea of a cruise holiday attractive? The surefire sign for many people is having to ask a teenager how a piece of technology works — this is probably not that applicable to most Hackaday readers.

How about when you’re shocked to encounter a significant part of your youth in a museum? These are supposed to be places of The Olden Days, full of rustic agricultural tools or Neolithic pottery, yet here you are in front of your teenage years presented for all to see. You have two choices: you can surrender to the inevitable and henceforth only wear beige clothing, take up golf or maybe book that old person’s cruise holiday, or you can dive in misty-eyed and reacquaint yourself with everything in front of you.

The above is probably an experience many regulars of these pages would share on a visit to Britain’s National Museum Of Computing in a corner of the famous Bletchley Park site, home of Britain’s wartime codebreaking efforts. They describe what they do on their web site as follows:

We conserve, restore, reconstruct, and give hands-on access to historic computers and related artefacts – with a particular focus on those which were the result of pioneering British ingenuity.

For the visitor this means that their galleries contain a huge array of computing and associated equipment, many of which are presented as working exhibits without too much of the dumbing-down that pervades so many other museums, and that the staff are extremely knowledgable about them.

The museum is housed in one of the groups of wartime codebreakers’ huts, laid out roughly in the shape of a capital H with the top of one vertical lopped off. If you are a connoisseur of British wartime sites you’ll recognise these buildings, they were built to a fairly standard design all over the country. Internally this means that the galleries are structured around the long corridors that are a staple of that era, giving in particular the earlier exhibits a feel of their time.

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Colossus: Face To Face With The First Electronic Computer

When the story of an invention is repeated as Received Opinion for the younger generation it is so often presented as a single one-off event, with a named inventor. Before the event there was no invention, then as if by magic it was there. That apple falling on Isaac Newton’s head, or Archimedes overflowing his bath, you’ve heard the stories. The inventor’s name will sometimes differ depending on which country you are in when you hear the story, which provides an insight into the flaws in the simple invention tales. The truth is in so many cases an invention does not have a single Eureka moment, instead the named inventor builds on the work of so many others who have gone before and is the lucky engineer or scientist whose ideas result in the magic breakthrough before anyone else’s.

The history of computing is no exception, with many steps along the path that has given us the devices we rely on for so much today. Blaise Pascal’s 17th century French mechanical calculator, Charles Babbage and Ada, Countess Lovelace’s work in 19th century Britain, Herman Hollerith’s American tabulators at the end of that century, or Konrad Zuse’s work in prewar Germany represent just a few of them.

So if we are to search for an inventor in this field we have to be a little more specific than “Who invented the first computer?”, because there are so many candidates. If we restrict the question to “Who invented the first programmable electronic digital computer?” we have a much simpler answer, because we have ample evidence of the machine in question. The Received Opinion answer is therefore “The first programmable electronic digital computer was Colossus, invented at Bletchley Park in World War Two by Alan Turing to break the Nazi Enigma codes, and it was kept secret until the 1970s”.

It’s such a temptingly perfect soundbite laden with pluck and derring-do that could so easily be taken from a 1950s Eagle comic, isn’t it. Unfortunately it contains such significant untruths as to be rendered useless. Colossus is the computer you are looking for, it was developed in World War Two and kept secret for many years afterwards, but the rest of the Received Opinion answer is false. It wasn’t invented at Bletchley, its job was not the Enigma work, and most surprisingly Alan Turing’s direct involvement was only peripheral. The real story is much more interesting.

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