Mysterious Files PH

This week Jonathan chats with Jonathan Pallant about embedded Rust! Learn about the growing Rust driver library, the different ways to build a Rust stack on an embedded device, and how the opinionated tooling can make you a better programmer!

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If you’d rather read along, here’s the transcript for this week’s episode.

Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)

Licensed under Creative Commons: By Attribution 4.0 License

It’s time to return to our no-punches-pulled look at food manufacture, and this time we’re looking at the humble loaf of bread. As before, we’re approaching the subject with a look at breadmaking both in the traditional sense that marketing people would like you to imagine, and in the modern sense of the loaf you’ll find on your supermarket shelf.

A Food Of Great Cultural Significance

Perhaps there are few foods with as much cultural significance as bread. If your distant ancestors took the path of growing grain as their major subsistence carbohydrate, the chances are there will be some form of bread woven into your identity. Where this is being written for example were I to head for the cathedral of a Sunday morning I would recite the Lord’s Prayer as part of the service, Give us this day our daily bread. Whether your culture leavens its bread or not, or whatever grain it uses, the chances are that there will be something similar about the humble foodstuff within it.

Sitting in a coffee shop writing this a few streets away from that cathedral in a British county town, the bread here is made from wheat flour and leavened using yeast. I’d hazard a guess that it’s the loaf most of you reading this will find at your local store, and with apologies to people whose bread takes a different form it’s the bread I’ll be examining here. It’s the loaf the wheat fields where I grew up supply grain for, so it’s the one whose production I’m most familiar with.

The Ideal Bread, At Least For The Adverts

Advertising for bread is steeped in a tradition both real and imaginary, but behind the image does lie an artisan past. Very few English villages did not have a mill or a baker, whether the stone grinding wheels were driven by water or wind. The bread would have been made in much the same way as you’d make it in your 21st century kitchen, with the flour being mixed with water to a dough, before being slowly proved and leavened using a yeast culture, and baked. The oven would have been a wood-fired domed clay or brick affair rather than a gas or electric device, and perhaps our artisan baker of yore wouldn’t have used a neat rectangular tin, but the final product would be something you’d recognise.

You can still buy artisan bread made this way and it’s a fine product, but despite the industry leaning heavily on such imagery the loaf in your supermarket is not quite the same. This is not a judgement on its quality but a statement on the technological advancement that has given us an affordable, consistent, and often high quality mass produced product.

First, Chase The Ingredients

So to start with 21st century bread making, we need to stand in an Oxfordshire field like the one surrounding where I grew up. It’s the end of July, so the wheat is being harvested. The field will be part of a crop rotation scheme, so it may have had canola, beans, or any of a number of other crops grown in it the previous year. The wheat may be so-called hard wheat, usually a winter wheat with a high gluten content planted last autumn, or depending on the bread process it can be a spring-planted variety with a lower gluten content.

The wheat will be stored by the farmer in a silo until the best price can be had for it, then once sold it goes to a mill. A modern industrial mill rather than the rustic watermill of our previous description, but the principle is the same. The grain may be moistened to aid the separation of its outer husk, and then it’s passed through sets of rollers to grind it. This results in a flour, but it’s not the flour you buy, nor is it the flour that goes into your bread.

A single piece of grain, a wheat seed, is loosely comprised of three components. The endosperm is the white flour portion you may recognise, the wheatgerm is the embryo, the part of the grain which germinates, and the outer husk is referred to as bran. The raw flour is wholewheat flour and you can bake with it, but it has the problem of a limited shelf life as the wheatgerm will spoil after milling if left. This the three components are separated, and the wheatgerm is heat treated to render it inert. The flour used for baking bread is thus compounded from these components to the formulation required, along with a set of additives to preserve it, improve its baking qualities, or add vitamins and nutrients. For a flour to be referred to as wholemeal its proportions of these components are defined by law, at least where this is being written.

The other major bread ingredient is yeast, which for a modern baker is a carefully maintained monoculture of a yeast strain selected for best performance in baking. The traditional method of farming a yeast strain is something we had a look at back in the pandemic when there was a shortage of the stuff, and its industrial equivalent is a much more sterile and scientifically controlled version of the same thing. It will arrive at the baker not as the dried yeast you’ll pick up at the supermarket but as a damp paste, which will be activated by dissolving it in a sugar solution.

A Loaf That’s Better Bread

For a traditional or specialty style bread then, the baker will take a compounded strong flour and fresh yeast, and follow a surprisingly similar process to that of the rustic baker mentioned earlier. The equipment will be stainless steel and the quantities may be greater, but our baker from the past would recognise it. It makes lovely bread, and you have no doubt enjoyed it in your time.

The more mundane loaves in your supermarket though, are not made in quite the same way. They take flour and yeast and make a leavened dough just as with a traditional loaf, but the process is very different indeed. The Chorleywood process, named after the town hosting the research institution where it was invented, is a high-speed baking process designed to use a wheat with a much lower gluten content than traditional bread. The problem facing the mid-20th-century researchers who created it was that the UK’s climate and agriculture isn’t suitable for growing the quantities of hard wheat its bread market demanded. Their innovation was to replace the leavening and proving of the traditional bakery with high-speed mechanical mixing, which since some of the gluten is broken down in the traditional fermentation, requires less gluten. The result is an extremely fast industrial process that produces an extremely consistent light and fluffy bread, and over the last three quarters of a century it has become the dominant loaf. It’s likely that wherever you are, a similar process tailored to your country is also responsible for most of your bread.

So you now know a little about where your daily bread comes from, and how it is made. As is usual for this series, it’s now time to look at the various claims and controversies surrounding the modern loaf, which can sometimes even take on a political dimension. Is the nutritional value of a supermarket load less than that of an artisan loaf made by that village baker? This is a question which has caused some considerable controversy over the years.

As we said earlier, modern flour is a refined and processed product whether it’s wholemeal or bleached white, and a process such as the Chorleywood one is designed to make a loaf from a cheaper ingredient. It’s then not unreasonable to suppose that the artisan loaf might be a better product, and in the sense of flavours and textures imparted by the traditional process you would probably be right to take that view. An artisan loaf is a high quality culinary experience.

But from the nutritional perspective it becomes a much less clear-cut assessment, because while a true artisinal loaf contains all the nutrients of the raw grain, the formulated flour used by the industrial baker has its nutrition precisely controlled. If the recipe uses a high-nutrition flour then the resulting bread has a high nutritional value, and since at least where this is being written such things are regulated, you can eat a Chorleywoord loaf with confidence that it’s not a nutritional desert.

As a parting thought I’d say this: eat the highest quality bread you can, support artisan producers if you can, you’ll eat some really nice bread. But don’t worry too much about the cheaper stuff, it’s only cheaper because it’s mass-produced, not because it’s worse for you.

If you’ve ever thought about the nomenclature of electrical components, potentiometer stands out as a strange name, etymologically suggesting something like a voltmeter. In fact, the component took its name from a voltage-measuring instrument also named the potentiometer. [Alnwlsn] recently took a look at one such device, which was integrated into a thermometer, and the Weston cell used to calibrate it.

The potentiometer (instrument) has a galvanometer at its heart. One side of the galvanometer is connected to the center lead of a potentiometer (component) which spans a voltage source; the other side is connected to a reference voltage. The potentiometer can be adjusted until no current flows through the galvanometer, at which point both sides match the reference voltage. The reference voltage source can then be replaced with some other source, which can then be measured relative to the reference by adjusting the potentiometer until both the voltages match. The reference voltage source is a Weston cell, which uses two mercury electrodes, one amalgamated with cadmium, to produce a stable 1.018 volt reference; despite being 74 years old, this particular cell still measured at 1.017 volts.

In this case, the potentiometer was made to measure the voltage produced by a thermocouple. After calibrating the potentiometer and connecting an iron-constantan thermocouple, [Alnwlsn] tested it with ice and boiling water, and in each case it proved accurate. In a more extreme test, it captured the temperature difference between the base and the tip of an alcohol flame.

For a bit more on the history of similar devices, check out the history of Weston Electrical Instruments.

Thanks to [PeterF] for the tip!

As strong and light as carbon fiber-epoxy composites are, the same can’t always be said of carbon-fiber reinforced 3D printer filaments. Of those that do improve over stock filament, the best performance comes from long, continuous strands, but the printers that can embed these are quite expensive. [MagicLAG], looking for a cheaper method, made something even stronger: prints reinforced with subsurface carbon-fiber cloth.

They tried a few other methods first, including pausing the print and manually embedding carbon fiber strands, ironing strands into the finished part, and ironing carbon fiber cloth into the bottom layer. For the main method, though, he printed the test part in three pieces: a core part, and two outer shell layers. Between the core and the shell is a small gap, into which carbon-fiber cloth can be epoxied. Under good conditions (not using quick-setting epoxy), this mostly preserves the outer surface and dimensional accuracy.

To test the various strengthening methods, [MagicLAG] printed hooks and tensioned them on a load cell until failure. None of the methods using single-stranded fiber showed any improvement; the fiber simply bent and let the surrounding plastic break. As a control for the epidermal cloth parts, they printed shells and cores and epoxied them together. These controls performed better than the standard parts, but not nearly as well as the carbon-fiber cloth composites. With only a few layers of cloth, these more than tripled the yield strength of the basic hook.

If you’d rather use a carbon-fiber filament, the type of plastic matters; carbon fiber makes PLA, at least, weaker. Regardless of form, some caution is called for whenever handling carbon fiber, since it seems to show some asbestos-like effects.

If you used a serious computer pre-IBM PC, there was a fair chance its operating system was CP/M. CP/M was a staple among 8080 and Z80 computers and while there were other versions, we’ll always associate CP/M with the Z-80. There was a CP/M made for the PC which used an 8088 (a hybrid 8-bit bus with a 16-bit 8086 core), but it was overwhelmed by MSDOS. However, there was another interesting version made for the 68000, and now [johnsonjh] has ported that over to create an early version of CP/M for 80386 protected mode.

The Z-80 only had a 16-bit address bus, so it could only handle 64K of memory. It was common to “bank switch” some memory, and CP/M Plus could be made to understand that (for example, you might have 32K of common memory and three banks of 32K memory; you could address one bank at a time). However, the 386 had a full-blown memory management unit that could remap physical 4K memory pages to anywhere in a program’s virtual address space.

Ordinary CP/M couldn’t handle that, but the Motorola 68000 had a similar page management model, so it makes sense it might be easier to port CP/M-68K to the 80386 than starting from the original, even though the instruction set for the Z-80 is conceptually more similar to the 80386.

What can you do with it? We don’t know. Presumably, it will allow you to use lots of memory. Historically, CP/M software from one variant would not run on another, so you’ll have to build anything you want to use. Of course, the real killer for lots of CP/M memory was multitasking, but that takes MP/M, and only about half of that is currently working. But we won’t be surprised to see it completed soon.

While CP/M skills won’t land you many jobs these days, it is a pretty good way to get mentioned on Hackaday.

Over the years I have been to many hacker camps and done a lot of very cool things, but BornHack 2026 brought me something entirely new: Radio. By which I don’t mean radio in terms of amateur radio, LoRa, or whatever, but Radio. Broadcast radio, because the camp had a special event FM radio station for the first time. And because in a previous life I spent an inordinate amount of time in my university’s student radio station and have the Radio Voice to prove it, I was totally there for it.

For a hacker camp, one of the special things about BornHack Radio was unexpected, that it was entirely analogue. No online streams, the only broadcast was over the air, 5 watts ERP from a vertical antenna stuck on a mast at the highest point of the Hylkedam scout camp site. I don’t know whether any of the residents of the isle of Funen listened, or what they made of it, but it certainly reached as far as the two closest towns.

The other unexpected feature of the station was that it had no music licensing. Personally I viewed this as an asset, because it forced the programming to be hacker-focused rather than suit the musical tastes of whichever people are enthusiastic enough to be DJs. I sincerely hope they don’t get a music licence at future events, speech-only gives it a special quality.

The studio for an analogue station like this one can be surprisingly simple, in that it’s a mixing desk to bring all the different microphones and other inputs together and set the levels, and not a lot else. the whole thing was in a Coleman shelter on the main drag through the camp, so as studios go it could have been quieter. Programming varied from talk shows through interview shows, a live feed from the speaker tent — is this the first ever Hacker Jeopardy broadcast? — and a beautifully done robotic numbers station which I suspect may also have been part of one of the on-camp games.

I brought two shows to the airwaves, both recorded, the first of which was a BornHack take on the Hackaday Podcast format, and the second a half-hour roving interview show. I believe I may be the first person ever to live-commentate a pixelflood screen in the style of Formula One coverage.

The thing that struck me most in my first foray into radio journalism was how straightforward it was. Wander the camp with microphone (complete with fluffy windshield and 3D-printed Hackaday cube), drop the results into Audacity, and a remarkably straightforward editing process compared to video. Last time I did this it involved 1/4″ tape and a razor blade.

So that was BornHack Radio, a new experience at a hacker camp both for those of us who ventured forth on the airwaves, and I hope also for the listeners. A format in which the live shows disappeared into the aether rather than having an online afterlife gave the whole thing a freedom rarely found in 2026. I really hope this isn’t the last time I break out the fluffy microphone at a hacker camp.

Thanks to [⁨Morel Sourvalley⁩] for the images.

In the 1980s, France was the stage for one of the boldest public computing projects of the era. Minitel was the French take on viewdata, and instead of making it an expensive and unattainable luxury, they made the terminals universally available. Many Minitel services cost extra to use, but despite this it was a runaway success that lingered on into the 21st century.

The ubiquitous terminals are now surplus to requirements, but that’s not to say they are useless. [MemoireMorte] has proved this with the Memo-1, a 6502-based computer designed to plug into a Minitel-1 terminal. It’s just the accessory your Minitel needs!

Hardware wise it’s a relatively conventional device with the usual RAM, ROM, and BASIC. There’s an expansion port, and a 6522 to provide a couple of Atari joystick ports. The serial port uses a a 6551 ACIA rather than the more usual W65C51 because of an incompatibility between the latter chip and the Minitel-1.

We like this computer, not because of novelty, after all it’s hardly the first 6502 we’ve seen, but because of its use of the Minitel terminal. These devices are magnificent, and deserve more love. We subjected another terminal to a teardown a year or two ago.