A Quarter And A Dime Will Get You A Commodore 64 Softmodem

January 20, 2025 by Zoe Skyforest 43 Comments

Back in the 1980s, a viable modem cost hundreds of dollars. Even in the 1990s, you were looking at spending a a Benjamin or two to get computer squawking down the phone lines. According to [Cameron Kaiser], though, it’s possible to whip up a softmodem using a Commodore 64 for much cheaper than that. How much? Just 35 cents, we’re told!

The inspiration was simple—Rockwell apparently used to build modems using the 6502. The Commodore 64 has a 6502 inside, pretty much, so surely it could be a softmodem, right? Indeed, one [John Iannetta] had done this in a one-way form in the 1980s, using the Commodore 64’s SID audio chip to output data in sound form. In 1998, he espoused the 35-cent modem—basically, the price of buying an RCA jack to hook up a phone line to your Commodore 64.

As [Cameron] found out, the concept still works today, as does [John’s] code, but it’s more like 68 cents in 2025 dollars. With the right bits and pieces, and a little code, you can have your C64 modulating data into sound at rates of 300 baud.

It’s hacky, slow, and there’s no real way to receive—the C64 just doesn’t have the chops to demodulate these kinds of signals on its own. You also shouldn’t use it on a real phone line if you don’t want to damage your C64. Still, it’s a wonderful bit of hackery, and it’s fun to see how well it works. We’ve seen some other great Commodore 64 modem projects before, like the ever-useful RetroModem. Meanwhile, if you’ve got your own communication hacks for the computers of yesteryear, don’t hesitate to let us know!

3D-Printed RC Car Focuses On Performance Fundamentals

January 20, 2025 by Zoe Skyforest 8 Comments

There are a huge number of manufacturers building awesome radio-controlled cars these days. However, sometimes you just have to go your own way. That’s what [snamle] did with this awesome 3D-printed RC car—and the results are impressive.

This build didn’t just aim to build something that looked vaguely car-like and whizzed around on the ground. Instead, it was intended to give [snamle] the opporunity to explore the world of vehicle dynamics—learning about weight distribution, suspension geometry, and so many other factors—and how these all feed into the handling of a vehicle. The RC side of things is all pretty straightforward—transmitter, receiver, servos, motors, and a differential were all off-the-shelf. But the chassis design, the steering, and suspension are all bespoke—designed by [snamle] to create a car with good on-road handling and grip.

It’s a small scale testbed, to be sure. Regardless, there’s no better way to learn about how a vehicle works on a real, physical level—you can’t beat building one with your own two hands and figuring out how it works.

It’s true, we see a lot of 3D printed RC cars around these parts. Many are built with an eye to robotics experimentation or simply as a learning exercise. This one stands out for its focus on handling and performance, and of course that nicely-designed suspension system. Video after the break.

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Modulathe Is CNC Ready And Will Machine What You Want

January 20, 2025 by Zoe Skyforest 14 Comments

Once upon a time, lathes were big heavy machines driven by massive AC motors, hewn out of cast iron and sheer will. Today, we have machine tools of all shapes and sizes, many of which are compact and tidy DIY creations. [Maxim Kachurovskiy]’s Modulathe fits the latter description nicely.

The concept behind the project was simple—this was to be a modular, digital lathe that was open-source and readily buildable on a DIY level, without sacrificing usability. To that end, Modulathe is kitted out to process metal, wooden, and plastic parts, so you can fabricate in whatever material is most appropriate for your needs.

It features a 125 mm chuck and an MT5 spindle, and relies on 15 mm linear rails, 12 mm ball screws, and NEMA23 stepper motors. Because its modular, much of the rest of the design is up to you. You can set it up with pretty much any practical bed length—just choose the right ball screw and rail to achieve it. It’s also set up to work however you like—you can manually operate it, or use it for CNC machining tasks instead.

If you want a small lathe that’s customizable and CNC-ready, this might be the project you’re looking for. We’ve featured some other similar projects in this space, too. Do your research, and explore! If you come up with new grand machine tools of your own design, don’t hesitate to let us know!

Thanks to [mip] for the tip!

You Can Now Play DOOM In Microsoft Word, But You Probably Shouldn’t

January 20, 2025 by Zoe Skyforest 23 Comments

DOOM used to primarily run on x86 PCs. It later got ported to a bunch of consoles with middling success, and then everything under the sun, from random embedded systems to PDFs. Now, thanks to [Wojciech Graj], you can even play it in Microsoft Word.

To run DOOM inside Microsoft Word, you must enable VBA macros, and ignore security warnings, to boot. You’ll need a modern version of Word, and it will only work on Windows on an x64 CPU. As you might imagine, too, the *.DOCM file is not exactly lightweight. It comes in at 6.6 MB, no surprise given it contains an entire FPS. It carries inside it a library called doomgeneric_docm.dll and the whole doom1.wad data file. Once the file is opened, a macro then extracts all the game data and executes it.

If you think that Microsoft Word doesn’t really have a way of displaying live game graphics, you’d be correct. Instead, that DLL is creating a bitmap image of the game state for every frame, which is then displayed inside Word itself. It uses the GetAsyncKeyState function to grab inputs from the arrow keys, number keys, and CTRL and space so the player can move around. It certainly sounds convoluted, but it actually runs pretty smoothly given all the fuss.

While this obviously works, you shouldn’t get in the habit of executing random code in your word processor. It’s just not proper, you see, like elbows on the dinner table! And, you know. It’s insecure. So don’t do that.

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Innovative Clock Uses Printed Caustic Lens

January 20, 2025 by Zoe Skyforest 13 Comments

Hackers and makers have built just about every kind of clock under the sun. Digital, analog, seven-segment, mechanical seven-segment, binary, ternary, hexadecimal… you name it. It’s been done. You really have to try to find something that shocks us… something we haven’t seen before. [Moritz v. Sivers] has done just that.

Meet the Caustic Clock. It’s based on the innovative Hollow Clock from [shiura]. It displays time with an hour hand and a minute hand, and that’s all so conventional. But what really caught our eye was the manner in which its dial works. It uses caustics to display the clock dial on a wall as light shines through it.

If you’ve ever seen sunlight reflect through a glass, or the dancing patterns in an outdoor swimming pool, you’ve seen caustics at play. Caustics are the bright patterns we see projected through a transparent object, and if you shape that object properly, you can control them. In this case, [Moritz] used some GitHub code from [Matt Ferraro] to create a caustic projection clockface, and 3D printed it using an SLA printer.

The rest of the clock is straightforward enough—there’s some WS2812 LEDs involved, an Arduino Nano, and even an RP2040. But the real magic is in the light show and how it’s all achieved. We love learning about optics, and this is a beautiful effect well worth studying yourself.

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Android Head Unit Gets Volume Knob Upgrade

January 17, 2025 by Zoe Skyforest 21 Comments

Touch screen head units are pretty much the norm these days. Many compromise with annoying on-screen volume controls or tiny buttons. If you find yourself with such a unit, you might like to hack in a real volume knob. [Daniel Ross] shows us how to do just that.

The build uses an ATMega328 as the heart of the operation, though [Daniel] notes an Arduino Uno or Mini would have done just fine. It’s set up with a 74HC14 hex Schmitt trigger, and a CD4066 quad bilateral switch on a custom PCB. As for the volume knob itself, it’s not a real analog pot, instead it’s using a rotary encoder with a center push button. The way it works is that the Arduino reads the encoder, and figures out whether you’re trying to turn the volume up or down based on the direction you’re turning it. It then sends commands to the CD4066 to switch resistors in and out of circuit with lines going to the stereo to emulate the action of volume buttons on the steering wheel.

[Daniel’s] guide explains how everything works in greater detail, and how you can calibrate your head unit to accept these signals while preserving the function of your actual steering wheel volume buttons. Then you just have to find a neat way to integrate the knob into your existing dashboard.

We don’t see as many car stereo hacks in this era when infotainment systems rule all, but we’ve seen some great stuff from older vehicles over the years. Video after the break.

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You Can Build Your Own Hubless Roller Blades And Ride Off Road

January 17, 2025 by Zoe Skyforest 19 Comments

Regular roller blades go way back, relying on a number of wheels mounted in a line and relying on regular bearings. [The Q] came up with an altogether more interesting design by handcrafting some tall skates with two hubless wheels apiece.

The build eliminates the hard work of creating the shoe part of the skates. Instead, an existing pair of roller blades was used, and modified to run the alternative hubless setup. The hubless wheels themselves were built by essentially wrapping a few large ball bearings with foam tires from an existing scooter wheel. The ball bearings have a large internal diameter, which creates the hubless look. They’re then mounted to a replacement steel frame that was mounted to the original skates.

Are there any benefits to hubless wheels in this application? Probably not, other than aesthetics. These skates are far heavier than before, and with poorer rolling resistance. However, we will note that the softer foam tires and large rolling diameter would probably offer some benefits on rougher surfaces. They even appear to work on hard-packed dirt, which is pretty impressive.

In any case, it’s always neat to see oddball designs that challenge our perception of what can and can’t be achieved on a mechanical level. These things don’t always have to make sense from an efficiency standpoint to be fun.

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