Year: 2022

Maiden Kansas City Keyboard Meetup Was A Clacking Good Time

August 30, 2022 by 10 Comments

Wow! I can’t believe it already came and went — but the first annual (semi-annual?) Kansas City Keyboard Meetup was, in my opinion, a rousing success. And I think organizer and Discord-nominated god among men [Ricardo] agrees with me. (He does; I checked before we left the venue.)

First of all, the attendance was off the charts, perhaps thanks in part to our announcement last week. We aim to get you the news sooner next time, in case you want to come in from surrounding states and municipalities. RSVPs sat around 20-something, and then shot up to 60 or so in the days leading up. Fortunately, there were enough tiny sandwiches, granola bars, and s t i c k e r s to go around. I already put mine on my keebin’ toolbox.

The Hive Was Buzzing

The event took place at Hive Co-Working thanks to [Nick], and overall, the space turned out to be a good layout. We were set up right inside the windows looking out to the street, and I like to think that we drew in a few passers-by, though I am probably more than a little bit biased. I wondered aloud on the way home how a sandwich board out on the sidewalk would have affected the influx of randos.

My husband pointed out that even though we were all the way downtown, this is Kansas City and not New York City, and most of the keyboard enthusiasts about town were already accounted for. Hmpf. I still say we should try a sandwich board next time. We could go meta and mention the tiny sandwiches inside. Don’t worry — there was plenty of sanitizer and napkins to go around, plus a box of gloves.

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C64 Turned Theremin With A Handful Of Parts

August 30, 2022 by 7 Comments

The theremin is popular for its eerie sound output and its non-contact playing style. While they’re typically built using analog hardware, [Linus Åkesson] decided to make one using the venerable Commodore 64.

The instrument works by measuring the capacitance between its two antennas and the Earth. As these capacitances are changed by a human waving their hands around near the respective pitch and volume antennas, the theremin responds by changing the pitch and volume of its output.

In this case, the humble 555 is pressed into service. It runs as an oscillator, with its frequency varying depending on the user’s hand position. There’s one each for pitch and volume, naturally, using a clamp and spoon as antennas. The C64 then reads the frequency the 555s are oscillating at, and then converts these into pitch and volume data to be fed to the SID audio chip.

[Linus Åkesson] demonstrates the build ably by performing a slow rendition of Amazing Grace. The SID synthesizer chip in the C64 does a passable job emulating a theremin, used here with a modulated pulse wave sound. It’s an impressive build and one we fully expect to see at a big chiptune show sooner rather than later. We’re almost surprised nobody came out with a C64 Theremin cartridge back in the day.

We’ve seen other fancy theremin-inspired builds recently too, like this light-based design.

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DIY guide saw

A Beautiful DIY Guided Saw

August 30, 2022 by 19 Comments

[JSK-koubou] has quite the talent for creative woodwork, particularly building interesting tools or improving existing ones. This recent project (multiple build videos below: part 1, part 2, and part 3) is a very flexible type of guided pull saw, whereby a fine-toothed saw blade is fixed in the bed, and the workpiece is pulled over it it. By fixing it at a shallow angle, and enabling the blade to be raised up through the bed, the workpiece can be progressively cut by simply pulling it over the blade, then winding it up a little until the final cut length is achieved.

From a construction perspective, the tool is all-metal, built from a collection of the off-the-shelf parts, and thick, hand-cut aluminium alloy plate, nary a CNC tool in sight. The only unusual component is the saw blade itself, which might be a bit tricky to track down if you were so inclined to reproduce the build. It appears (well if you believe the auto-translation by Google Lens, anyway) to be a spare blade for a commercial guide saw available in Japan at least.

We found it particularly pleasing to see the use of a home-built anodizing setup to give it a bit of a jazzy color scheme for some of the plates, just because. Like with many of the build videos from this YouTuber, it is well worth watching all of them, if only just to gather a few ideas for one’s own workspace, if you can stop yourself getting distracted looking at all the other neat tools he uses on the way.

DIY tool builds are not uncommon in these parts, here’s a neat DIY combo table-based project, and here’s a homebrew auto-lowering metal bandsaw which could be a real timesaver.

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A Primer For The Homebrew Game Boy Advance Scene

August 29, 2022 by 10 Comments

As video game systems pass into antiquity, some of them turn out to make excellent platforms for homebrew gaming. Not only does modern technology make it easier to interact with systems that are now comparatively underpowered and simpler, but the documentation available for older systems is often readily available as well, giving the community lots of options for exploration and creativity. The Game Boy Advance is becoming a popular platform for these sorts of independent game development, and this video shows exactly how you can get started too.

This tutorial starts with some explanation of how the GBA works. It offered developers several modes for the display, so this is the first choice a programmer must make when designing the game. From there it has a brief explanation of how to compile programs for the GBA and execute them, then it dives into actually writing the games themselves. There are a few examples that [3DSage] demonstrates here including examples for checking the operation of the code and hardware, some simple games, and also a detailed explanation the framebuffers and other hardware and software available when developing games for this console.

While the video is only 10 minutes long, we recommend watching it at three-quarters or half speed. It’s incredibly information-dense and anyone following along will likely need to pause several times. That being said, it’s an excellent primer for developing games for this platform and in general, especially since emulators are readily available so the original hardware isn’t needed. If you’d like to build something from an even more bygone era than the early 2000s, though, take a look at this tutorial for developing games on arcade cabinets.

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Genshin Security Impact

August 29, 2022 by 29 Comments

An MMORPG with cute anime-style characters and maybe a bit too much inspiration taken from another classic Nintento franchise, Genshin Impact is a relatively popular game across the PlayStation, iOS, Android, and PC platforms. That last one has already generated a bit of controversy, since the PC version game includes an anti-cheat kernel driver that runs in the Windows kernel context, and on initial release that module kept running even after the game was closed.

That anti-cheat driver is back in the news, with Trend Micro discovering a ransomware campaign that includes mhyprot2.sys, the anti-cheat driver, as a component of the infection. The module is known to have vulnerabilities, and is still a signed kernel driver, so the malware campaign loads the driver and uses its functions to disable anti-malware protections.

The rest of the campaign is straightforward. Starting with access to a single domain-connected machine, an attacker uses that foothold to gain access to the domain controller. The malicious script is hosted on shared storage, and PsExec is used to run it on all the domain member machines. The real novelty here is the use of the vulnerable anti-cheat kernel driver as the anti-malware bypass. As far as we can tell, this driver is *still* signed and considered trustworthy by Windows. We join the call to Microsoft, to revoke this vulnerable driver, as it’s now actively being used in ongoing malware campaigns. For more on security, check out our weekly column on the topic,

$800 Mountain Bike Seat Post Chopped In Two

August 29, 2022 by 16 Comments

For those unfamiliar with the sport of mountain biking, it’s a wild hobby that is rife with hacking. It started in the early 70s when the first dedicated mountain bikers were hacking road bikes together to ride on trails to varying levels of success, but only in the last decade or so have there been a lot of electronics appearing in various bike parts that we can all tinker with as well. This video discusses some of the downsides with a very expensive electronic seat post on a mountain bike, and attempts to solve its shortcomings by cutting it in half.

This build involves a dropper seat post, which is an adjustable seat for mountain biking that functions like an office chair. By pushing a button on the handlebars, the seat post can be rapidly adjusted up or down on-the-fly. Normally these seat posts use a cable to actuate, but this expensive version is wireless. The only problem is the battery will occasionally fly off when hitting big jumps, so [Berm Peak Express] decided to cut the existing proprietary battery system out and create a new housing for it. The new housing has a wired extension for the battery in its new location under the seat instead of behind it, and this gives it the clearance it arguably should have had from the manufacturer.

While not the most involved project of all time, it does take a certain mentality to take a hacksaw to a bike part that costs more than a large percentage of bicycles. It’s a niche product to be sure, but it also shows that some of the biggest annoyances with proprietary parts are not too difficult to overcome. And, it is interesting to see the ways that some people are hacking bikes outside of admittedly clever ebike conversions.

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Magic Eye Tubes Go Solid State With This Plug-In Replacement

August 29, 2022 by 35 Comments

Perhaps nothing added quite so much to the charm of vacuum tube circuits from back in the heyday of the vacuum tube as did the “Magic Eye” indicating tube. With the ghostly green glow of its circular face, magic eyes stood in for more expensive moving-coil meters for things like tuning indicators and VU meters. And while they may be getting hard to come by today, fear not — this solid-state replacement for the magic eye tube is ready to stand in for your restoration projects.

To pull off this clever build, [Gord Rabjohn] started with original 6E5 and 6U5 magic eye tubes, presumably ones that either no longer worked or had become too weak to see. The glass envelopes of the cathode-ray tubes were carefully cut from the sockets, and the guts of the tubes were discarded to make room for the replacement circuit, which lives on two PCBs. A rectangular control board holds an LM3915 bar graph LED driver chip, while a round display PCB holds 120 surface-mount green LEDs. The circular display board is mounted at the top of the control board and perpendicular to it, with a diffuser mounted above the LEDs. Everything is stuffed back into the original glass envelope and socket, making this a plug-in replacement for the tube.

The effect is quite convincing, as shown in the video below. True, you can see some evidence of the individual LEDs even with the diffuser, but honestly this just makes the display look more like the iris of an eye. We really like the look of this and we appreciate the work [Gord] put into it, especially the documentation. For a little more on how the tubes worked, check out [Al Williams]’ article.

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