Big Chemistry: Liquefied Natural Gas

The topic of energy has been top-of-mind for us since the first of our ancestors came down out of the trees looking for something to eat that wouldn’t eat them. But in a world where the neverending struggle for energy has been abstracted away to the flick of a finger on a light switch or thermostat, thanks to geopolitical forces many of us are now facing the wrath of winter with a completely different outlook on what it takes to stay warm.

The problem isn’t necessarily that we don’t have enough energy, it’s more that what we have is neither evenly distributed nor easily obtained. Moving energy from where it’s produced to where it’s needed is rarely a simple matter, and often poses significant and interesting engineering challenges. This is especially true for sources of energy that don’t pack a lot of punch into a small space, like natural gas. Getting it across a continent is challenging enough; getting it across an ocean is another thing altogether, and that’s where liquefied natural gas, or LNG, comes into the picture.

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A homebrew computer built inside plexiglass cases with lots of LEDs

The Coleman Z80 Is A Modern Take On A 1970s Computer

[Joshua Coleman] likes to design his own computers. Sometimes, that means drawing up bus architectures,  memory maps and I/O port pinouts. Other times, he can focus his efforts more on the general aesthetics, as well as on building a great set of peripherals, as he shows in his latest ColemanZ80 project. Thanks to the RC2014 architecture defining most of the essential features of a classic Z80 computing platform, [Joshua] was able to design a modern retrocomputer that’s not only genuinely useful, but also looks as if it came off a production line yesterday.

The external design is a sight to behold: bright red laser-cut acrylic pieces form a neat, semi-transparent case with ventilation slots on the sides and lots of blinkenlights on the front. Inspired by 1970s classics like the Altair 8800, the front panel gives the user a direct view of the machine’s internal state and allows simple command inputs through a series of tumbler switches. The CPU, RAM and other basic devices are housed in one case, with all the expansion modules in a second one, linked to the mainboard through a 40-wire flatcable.

A hand-built Z80 computer's mainboard
Lots of classic chips, but also loads of hand-routed wires grace the ColemanZ80’s mainboard.

Although the mainboard closely follows the RC2014 design, [Joshua] went through a lot of effort to tune the system to his specific needs. The expansion boards he built include an NS16550 UART to replace the default 68B50, a battery-backed real-time clock, a YM2149-based sound card and even a speech synthesizer module built around the classic SP0256 chip, of Speak & Spell fame. An even more unusual feature is the presence of an AM9511, one of the earliest math coprocessors ever made, to speed up floating-point calculations. All of these modules were built entirely by hand on prototype boards: we can barely imagine how much time this must have taken.

Output devices include a VGA adapter courtesy of a Raspberry Pi Pico as well as a regular 4-digit 7-segment LED display and a set of classic HP “bubble” LEDs. [Joshua] runs several demos in his video (embedded below), ranging from computing the Mandelbrot set to playing chiptunes on the YM2149. There’s plenty of scope for further expansion, too: [Joshua] plans to build more peripherals including a floppy drive interface and a module to operate a robotic car.

This is not the first Coleman Z80 computer: the previous version ran on an architecture [Joshua] designed all by himself. We’ve seen several other impressive RC2014 derivatives, like a tiny micro version and this Altair-inspired case.

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The Gallium Nitride Revolution

[Asianometry] has been learning about gallium nitride semiconductors and shares what he knows in an informative video you can see below. This semiconductor material has a much higher bandgap voltage than the more common silicon. This makes it useful for applications that need higher efficiency and less heating.

The original use of the material was for LEDs, but we are seeing increasing use of the material in high-power applications like chargers. Phone chargers are especially common using this technology. This isn’t surprising when your think about how many phone chargers are needed worldwide every day.

Other places that need power-efficient devices are data centers, electric vehicles, and battery-operated equipment. It isn’t clear, though, that we can make enough of the material to meet global demand if it becomes extremely popular. This is especially true because the machinery and processes used to create silicon devices don’t work with gallium nitride. Silicon carbide is a competitor, and it could be easier to create, even though it isn’t as efficient as gallium nitride.

We’ve looked at gallium nitride before, and we are sure we are going to be seeing it again. Silicon carbide may one day operate on the surface of Venus. You can even use it to make homemade LEDs.

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All About USB-C: Connector Mechanics

There’s two cases when hackers have to think about USB-C connector mechanics. The first is when a USB-C connector physically breaks, and the second is when we need to put a connector on our own board. Let’s go through both of them.

Clean That Connector

What if a socket on your phone or laptop fails? First off, it could be due to dust or debris. There’s swabs you can buy to clean a USB-C connector; perhaps adding some isopropyl alcohol or other cleaning-suitable liquids, you can get to a “good enough” state. You can also reflow pins on your connector, equipped with hot air or a sharp soldering iron tip, as well as some flux – when it comes to mechanical failures, this tends to remedy them, even for a short period of time.

How could a connector fail, exactly? Well, one of the pins could break off inside the plastic, or just get too dirty to make contact. Consider a device with a USB-C charging and data socket, with USB 2.0 but without high-speed pairs – which is to say, sadly, the majority of the phones out there. Try plugging it into a USB-A charger using a USB-A to USB-C cable. Does it charge, even if slowly? Then, your VBUS pins are okay.

Plug it into a Type-C charger using a Type-C cable, and now the CC pins are involved. Does it charge in both orientations? Then both of your CC pins are okay. Does it charge in only one orientation? One of the CC pins has to be busted. Then, you can check USB 2.0 pins, used for data transfer and legacy charging. Plug the phone into a computer using a USB-A to USB-C cable. Does it enumerate as a device? Does it enumerate in both orientations? If not, you might want to clean D- and D+ pins specifically, maybe even both sets. Continue reading “All About USB-C: Connector Mechanics”

A Love Letter To My Lost Amiga

My first love was a black wedge. It was 1982, and I had saved up to buy a Sinclair ZX81. That little computer remains the only one of the huge number that I have owned over the years about which I can truly say that I understood its workings completely; while I know how the i7 laptop on which this is being written works I can only say so in a loose way as it is an immensely complex device.

Computing allegiance is fickle, and while I never lost an affection for the little Sinclair I would meet my true electronic soulmate around eight years later as an electronic engineering student. It no longer graces my bench, but this was the computer against which all subsequent machines I have owned would be measured, the one which I wish had not been taken from me before its time, and with which I wish I could have grown old together. That machine was a Commodore Amiga, and this is part love letter, part wistful musing about what could have been, and part rant about what went wrong for the best desktop computer platform ever made. Continue reading “A Love Letter To My Lost Amiga”

Mouse Whisperer Keeps You Working, Even When You Need A Break

When life hands you lemons, you make lemonade, right? What about when life hands you annoyingly intrusive work-from-home policies that require you to physically stay at your computer even though you really, REALLY need to go to the bathroom, but can’t be trusted to act like a responsible adult who won’t get diverted by TV or the fridge on the way back? In that case, you build something like the Mouse Whisperer — because malicious compliance is the best kind of compliance.

To be fair, [andrey.malyshenko] does list other plausible use cases for what amounts to an automatic mouse wiggler. Like many of us, [andrey] isn’t a fan of logging back in from screen locks, and recognizes that not absolutely every minute of work requires staring at one’s screen. There’s also the need for bio-breaks, of course, and the Mouse Whisperer is designed to accommodate these use cases and more.

The design is quite compact, occupying barely more space than a wireless mouse dongle. Plugged into a USB port, the ATtiny85 mostly sits idle, waiting to detect the touch of a finger on an exposed pad via a TTP223. The dongle then goes into a routine that traces lazy circles with the mouse pointer, plus flashes an RGB LEB on the board, because blinkenlights are cool. The mouse wiggling continues until you come back from your Very Important Business and touch the pad again.

Now, if anyone is actually monitoring you remotely, the circling mouse pointer is going to look a wee bit sus. Fear not, though — the code uses a *.h file to define the circle, so other patterns should be possible. Either way, the Mouse Whisperer is a nice solution, and it’s considerably more compact and integrated than some of the alternatives we’ve seen.

Closeup of a film restorer's hand holding a 35mm film print to check for defects as it goes into a film scanner

35mm Film Restoration Process Explained

For a large part of the 20th century, motion pictures were distributed on nitrate film. Although cheaper for the studios, this film was highly flammable and prone to decay. On top of that, most film prints were simply discarded once they had been through their run at the cinema, so a lot of film history has been lost.

Sometimes, the rolls of projected film would be kept by the projectionist and eventually found by a collector. If the film was too badly damaged to project again, it might still get tossed. Pushing against this tide of decay and destruction are small groups of experts who scan and restore these films for the digital age.

still showing the difference in quality between a 16mm print of a 35mm animated movie and a new scan of the 35mm original
The quality difference between a smaller-format print and the original restored negative can be startling

The process is quite involved – starting with checking every single frame of film by hand and repairing any damaged perforations or splices that could come apart in the scanner. Each frame is then automatically scanned at up to 10K resolution to future-proof the process before being painstakingly digitally cleaned.

The real expertise is in knowing what is damage or dirt, and what is the character of the original film. Especially in stop-motion movies, the subtle changes between frames are really part of the original, so the automatic clean-up tools need to be selectively reined in so as not to lose the charm and art of the film-makers.

The results are quite astonishing and we all have teams like this to thank for protecting our cultural heritage.

If you’re interested in watching the process, then check out the video after the break. If you fancy a go at automatic film digitising yourself (preferably not on unique historical prints!) then we’ve shown projects to do just that in the past.

Thanks to [Cliff Claven] for the tip.

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