Casual Repair And Maintenance On An Amiga 1000

Recently [Drygol] had an Amiga 1000 system over for some repairs as well as maintenance and general TLC. This is a Motorola 68000-based home computer from 1985 that also has the distinction of being the first Amiga system to be released by Commodore. At a time when the IBM PC was still strutting its monochrome and EGA graphics alongside PC speaker beeps, the Amiga 1000 featured relatively high-res graphics and advanced stereo audio courtesy of special accelerator chips.

Overall the system was in a pretty good condition, even coming with the very nifty modern Parceiro expansion that adds 8 MB of fast RAM, an SD card slot and RTC. This thus meant that they mostly just had to perform the typical maintenance task, such as recapping the PSU and mainboard, as well as recapping and lubing up the floppy drive. The original 230 VAC fan in the PSU also got swapped with a 12V unit that was much quieter.

After disassembling the keyboard for some deep cleaning and retr0brighting, a little glitch in the form of the use of a too long screw by a previous owner was addressed, as well as a broken plastic clip. With how little attention the Amiga 1000 received after its release it’s good to see some of these units still kicking.

Turning Glass Into A Touch-Sensitive Button

Although generally glass isn’t associated with touch-sensitive surfaces, the addition of an ITO (indium tin oxygen) coating adds the exciting property of not only being transparent to the visible light part of the electromagnetic spectrum, but also of being electrically conductive. The logical result is that fine folk like [Sokol] simply had to use their newly acquired ITO-coated glass to make a button out of.

Here the easy option is of course to just use it as a capacitive sensor where the conductive ITO layer is used for the capacitive charge and the glass provides the insulator, but here we see it demonstrated how to create a pressure-sensitive implementation instead.

The measured conductivity on the ITO-coated glass in the video is pretty good, at just over 20 Ohm. This thus makes said capacitive button very easy to achieve. To make it a touch-sensitive button, two pieces of glass are used, with the ITO sides facing. Paper is used to create a spacer, after which the slight flex of the glass allows for the two ITO surfaces to touch, completing the circuit.

This is somewhat similar to how resistive touch screens work, with the position of the finger or stylus determined by the resistance between the two sides. In a hobbyist setup this would make it fairly easy to create a multi-position touch screen using just two pieces of glass and some firmware.

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Using The Chimney Effect To Drop Passively Cooled PC Temperatures

The stack effect — also known as the chimney effect — is the basic principle that hot air not only rises, but if guided through a tube, the rising hot air will create more pressure that will effectively draw air more effectively into the tube. This is not only great for a chimney, but also a useful principle if you seek to cool something like a PC in a more passive manner. The main question is of course how much of a ‘chimney’ you need to see real effects for something like a typical water-cooled CPU’s radiator, as demonstrated by [der8auer] in a recent video.

Although there’s a lot of fun physics behind the stack effect that you can run the numbers on, the more practical demonstration here using 3D printed funnel segments for the radiator and various thermometers provides a very hands-on feeling for what you can expect from this approach.

With just a single segment stacked there is already a clearly noticeable temperature change, with the second segment creating a draft as visualized by the smoke machine. After this he goes for broke with the full stack and a resulting 19°C temperature drop on the CPU. While impressive, at this point the required funnel gets a bit silly, though the same principle has been applied to computer cases before, including the passively-cooled Power Mac G4 Cube and the 90-degrees-rotated SilverStone Raven series of cases, like the RV02.

The basic idea of making use of the fact that hot air rises, and maybe also banking on the stack effect for some free passive cooling, clearly isn’t so crazy.

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Fixing A JMicron-Based M.2 USB Enclosure That Stopped Working

As useful as USB-to-M.2 SSD adapters are, sometimes you come across a bit of a dud. A case in point is the Orico-branded TCM2-C3 that features both an attractive clear case and in its earlier revisions a JMicron controller-based circuit that apparently degrades over time, causing erratic boot behavior. After implementing a fix a few years ago, [Mark Furneaux] can happily report that the thus fixed enclosures are still working.

These faulty board revisions feature the JMicron JMS583 controller IC, which has a 1.0V core voltage input pin. Apparently to save power, Orico designed the board to target the minimum ~0.95V core voltage per the datasheet. Apparently due to component drift or degradation, this lower core voltage is after a while often not enough any more to start the controller, which thus translates into an unresponsive USB device and presumably some panic about lost data.

Although [Mark] doesn’t describe the fix in detail, it entails bumping up this core voltage to something closer to the nominal 1.0V, which restores functionality at the cost of presumably a measurable amount of extra heat production by said controller.

Later versions of the Orico TCM2-C3 enclosure switched from this JMicron controller to a Realtek one, which so far appears to be noticeably more reliable. Although Orico kept the same model name, the transparent enclosure makes it at least a snap to see which revision you are dealing with.

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DOOM Using Regular Expressions

Regular expressions (regexes) are an amazingly powerful way to perform operations on collections of e.g. text. Regexss can also be considered to be a programming language, even a Turing complete one. Ergo it’s perfectly acceptable to thus design a way to use regexes to run and play a game of DOOM, as [Artem Lytkin] recently did.

The GitHub project page can be found here, containing the Python-based code that allows the demonstration to run, as well as the other components, including the C runtime and the 96.6 MB text string that defines a CPU’s registers, RAM, a framebuffer, the DOOM engine compiled to this custom CPU’s instruction set and the WAD file for the game itself.

The C-based driver applies the fixed, ordered list of find-and-replace rules to this string, which after more than ten-thousand of such substitutions later results in a single frame of the game. At about 80,000 substitutions per second on the given test system, that gets you to a sort-of playable framerate, even.

Naturally, the practical value of playing DOOM like this is pretty low, but as a demonstration of why regexes are awesome it’s hard to beat.

How The Vagus Nerve Promotes Healthy Cognition Via Acetylcholine Signaling

It’s been said for centuries that you cannot think on an empty stomach, and that love goes through the stomach. Although these may seem like merely cute jabs at the simplicity of human nature, recent research in rat models by [Logan Tierno Lauer] et al. indicates that the gut may be more influential in something as fundamental as memory formation and cognitive function than previously assumed.

Key to the gut-brain connection is the vagus nerve, an essential part of the autonomic nervous system that wires the brain into the body’s organs, including the gastrointestinal (GI) tract. It provides both sensory and motor fibers, so that the brain can literally sense the state of said GI tract, with various triggers as result. One of these is – as demonstrated in the paper – the release of acetylcholine (aCh) an important neurotransmitters in the CNS for cognitive functions including attention, memory and motivation.

Using in vivo fiber photometry it was found that during eating medial septum neurons released aCh, with various ways to impair this mechanism along the vagus nerve leading to this response disappearing. This also confirms earlier research that points the finger at a so-called early life Western Diet (WD) causing impaired memory and overall cognitive function, likely due this high fat and high sugar diet causing dysfunction in this aCh regulation mechanism.

Beyond once again reinforcing the need to eat healthily, this research also provides further insights in condition with declining cognitive function, such as Alzheimer’s and dementia.

Samsung’s SmartThings API Terminates Free Access

If there’s one constant in the world of commercial home automation solutions, it is that of decreasing availability and higher costs as time goes on. So too with Samsung’s SmartThings, the API of which will cease free access in October of 2026.

While this does not affect people who use the SmartThings app, any system that relies on access to this API will soon face a $4.99 per month fee for non-commercial users, with various commercial tiers also in the pipeline. While the rest of the blog post has all the elegance of the output of a ‘please generate a list of plausible excuses’ query to ChatGPT, the most likely reason is that offering free services after the sale of an Internet of Things device will never be profitable.

SmartThings was originally a 2012 Kickstarter campaign that ended up becoming successful enough that the company was bought by Samsung in 2014. Its current offerings are very much like other Smart Home products, with recently added support for Matter and interoperability with third-party devices.

If you have SmartThings integrated with your Home Assistant installation, you are also likely affected by this change if at any point you use the API. Of course, this isn’t the first time that SmartThings customers had to scramble to fix broken infrastructure, such as when in 2021 the original hubs got discontinued.