When Nearly Flat Isn’t Really Flat

December 6, 2023 by Jenny List 84 Comments

An aerial photo of the UK city of Milton Keynes — Is Mk really flat? Thomas Nugent, CC BY-SA 2.0.

From where I am sitting, the earth is flat. The floor that runs the length of the unit my hackerspace sits in is flat, the concrete apron behind it on which we test our Hacky Racers is flat, and a few undulations in terrain notwithstanding, it remains flat as I walk up the road towards Stony Stratford.

Of course, Hackaday hasn’t lost its mind and joined the conspiracy theorists, the earth is definitely spherical as has been known and proved multiple times since antiquity. But my trivial observation made in a damp part of Buckinghamshire still holds; that for a given value of flat which disregards a few lumps and bumps in the ground, my corner of the English city of Milton Keynes is pretty flat. Which leads from a philosophical discussion to an engineering one, if I can reasonably describe a city-sized area on an Earth-sized sphere as flat, how flat does a surface have to be to be considered flat? And from that stems a fascinating story of the evolution of precision machining. Continue reading “When Nearly Flat Isn’t Really Flat” →

The Deere Disease Spreads To Trains

December 6, 2023 by Jenny List 37 Comments

If the right-to-repair movement has a famous story, it’s the familiar green and yellow John Deere tractor. Farmers and mechanics have done their own repairs as long as there have been tractors, but more recent Deeres have been locked down such that only Deere-authorised agents can fix them. It’s a trend that has hurt the value of a second-had Deere, but despite that it appears to be spreading within the machinery world. Now there’s a parallel on Polish railways, as Polish-made Newag electric passenger trains have been found to give errors when serviced by non-Newag workshops.

At the heart of the problem are the PLCs which control all aspects of a modern rail traction system, which thanks to a trio of Poland and Germany based researchers have been found to play a range of nasty tricks. They’ll return bogus error codes after a set date which would presumably be reset by the official service, if the train has been laid up for a while, or even if they are detected via GPS to have visited a third-party workshop. Their work will be the subject of a talk at 37C3 which should be worth watching out for.

It will be especially interesting to juxtapose the reaction to this revelation with cases such as the Deere tractors, because of course Poland is part of the European Union. We’re not specialist EU competition lawyers, but we know enough to know that the EU takes a dim view of these types of practices and has been strong on the right to repair. Who knows, Polish trains may contribute further to the rights of all Europeans.

Affordable Networking For Your Classic Mac

December 5, 2023 by Jenny List 1 Comment

The Mac SE and in particular the Mac SE/30 number among the more sought-after of the classic all-in-one Apple computers, and consequently their peripherals including network cards are also hard to find and pricey. Even attempts at re-creating them can be expensive, usually because the chips used back in the day are now nearly unobtainable. But if the search is widened to other silicon it becomes possible to create substitutes, as [Richard Halkyard] is doing with a modern version of the SE Ethernet card.

The chip which makes this possible is the Microchip ENC624J600, an embedded 10/100 Ethernet controller with an impressively configurable interface that can be easily mated to the 68k bus. For The SE it’s mapped to a memory area, while for the /30 there can be a declaration ROM which informs the machine where it is.

This is an as yet unfinished project, a work in progress. But it deserves to succeed, and if we can provide encouragement by featuring it here then it’s definitely worth a look. Or course, this is by no means the only replacement for an original board.

SE/30 picture: Cornellanense, CC BY-SA 4.0.

Retrotechtacular: The Gunsmith Of Williamsburg

December 5, 2023 by Jenny List 11 Comments

A modern firearm is likely to be mass-produced using high-precision machine tools, and with a uniformity to the extent that parts from one can be interchanged with those from another. This marks a progression of centuries of innovation, in gunsmithing, in machine tooling, and in metallurgy. In the 18th century there was little of the innovations found in a modern weapon, and a rifle would have been made entirely by hand through the work of a master gunsmith. The video below the break is a fascinating 1969 film following Wallace Gusler, the gunsmith at the museum town of Williamsburg, Virginia, as he makes an 18th-century muzzle-loading flintlock rifle from raw materials. It’s a long video, but it leaves nothing out and has a really informative commentary we’re told from the gunsmith himself.

The film opens with a piece of wrought iron being forged into a long strip. We’ve talked about wrought iron as a difficult-to-find blacksmith’s material before here, so this immediately makes us curious as to what material the current Williamsburg gunsmiths use. The strip is formed round a mandrel and laboriously forge-welded to form a rough tube, before being bored with a series of drills and then rifled with a toothed slug. The finishing is done by had with a file, with the rough tube being filed to an octagonal shape. Continue reading “Retrotechtacular: The Gunsmith Of Williamsburg” →

A Single Board Computer, With Vacuum Tubes

December 5, 2023 by Jenny List 8 Comments

We have occasionally featured vacuum tube computers here at Hackaday and we’ve brought you many single board computers, but until now it’s probable we haven’t brought you a machine that combined both of these things. Now thanks to [Usagi Electric] we can see just such a board, in the form of his UE-0.1, a roughly 260 by 210 mm PCB with 24 6AU6 pentodes on board that implements a simple one-bit CPU.

The architecture starts with the MC14500B 1-bit microcontroller, which was the subject of a previous vacuum tube computer. People found the unusual architecture difficult to understand, so this board is an even simpler take. It doesn’t have all the features of the Motorola original but it is (just) enough to be a CPU.

The tubes are arranged in groups of four with heaters in series from a 24 V supply, while the inputs and clock come in the form of on-board suitably retro-looking switches. The final touch is a VFD of the type used in bar graphs, were used to show the state of the various bits. It’s a fully working computer in the simplest sense, and definitely worth a look in the video below the break.

It would be interesting to see whether the tube count could be reduced further, or is this a record. The number of physical devices could be cut by using tubes with more than one device in them such as double-triodes, but perhaps that would be cheating.

Meanwhile, if you think vacuum computing is all about the old stuff, perhaps you should look at the state of the art.

Continue reading “A Single Board Computer, With Vacuum Tubes” →

Finally! A Typeface For Hardware People

December 4, 2023 by Jenny List 11 Comments

When it comes to novelty typefaces there is no shortage of weird and wonderful fonts to be found when you have finally tired of Comic Sans. Everything from bananas forming letters to Wild West saloon lettering can be yours, plus of course our favourite, the embossed Dymo label. But there’s a new kid on the novelty typeface block, and for us it sweeps all before it.

Scopin’ Sans is as its creator [Guy Dupont] calls it “A typeface for hardware people”, and its party trick is that it doesn’t produce letters. Instead it forms an oscilloscope trace that displays what it would look like as serial data. Instantly your text jumps straight to 1337, and you win the internet.

We have shamefacedly to admit that we don’t know binary ASCII by sight, so we’ll have to take his word for it. But for the curious there’s a demo from which you can amuse yourself creating traces, and if you can’t recognize serial ASCII then the chances are few of the people around you can either. We take our hats off to [Guy], and it’s something we’re sure we’ll use at some point to delight and confuse our friends. It’s not the first font we’ve brought you, here are some more if you come from the bitmap era.

Powering A Cavity Magnetron, From A Battery

December 4, 2023 by Jenny List 47 Comments

While vacuum electronic devices have largely been superseded over much of consumer electronics, there’s one place where they can still be found for now. The cavity magnetron is a power RF oscillator device in which electrons are induced to move in a circular path through a tuned cavity, inducing a high-power RF field, and it lies at the heart of a domestic microwave oven. They usually need a high-voltage mains transformer and a rectifier to work, but [Hyperspace Pirate] has managed to make a solid-state power supply to power one from a 12 volt battery. Better still, he’s put the resulting combo in a Care Bears lunchbox. Take a look at the video below the break.

The video starts with a potted history of the magnetron before looking at the circuit of a typical oven, which uses a single diode and a capacitor in a simple voltage multiplier. The capacitor value is adjusted to lower the power output, and a pretty thorough job is done of characterising the circuit.

The low-voltage supply starts with an XVS inverter to make the high voltage via another multiplier, but the interesting part comes with the magnetron’s heater. It’s designed for 50 or 60Hz household electricity, but there it’s receiving 40 kHz and has an appreciable impedance. The addition of a capacitor soon restores it to a reasonable performance.

In case you noticed that the ZVS converter might be improved upon, take a look at a flyback converter. Meanwhile, we should probably echo the safety message in the video that playing with magnetrons and their associated transformers can be a nasty way to die. Please take care out there!

Continue reading “Powering A Cavity Magnetron, From A Battery” →