Emulating A Floppy Drive By Emulating The Drive Itself

October 12, 2026 by 1 Comment

The Commodore 1541 is famously the floppy drive for the Commodore 64 series of 8-bit computers, and can be found with relative ease. Not so well known is its 1551 sibling — the drive made for the Commodore 16 and Plus/4 machines.

They’re particularly rare in 2026, so [Maciej Witkowiak] has made an emulator. But it’s not just modern silicon emulating the whole thing. Instead it’s the same 6510 and ROM you might have found on the original, talking to a Pi Pico emulating the drive hardware. It’s a gloriously over the top solution to the problem of emulating a disk drive, the reason being that it started life as a daughter board plugged into an original drive mainboard.

Complementing the Pico is a CPLD for glue logic, and an OLED for selecting disk images. The Pico even generates the clock and IRQ timing for the venerable 8-bit part. The ROM is 64k in size, room enough for both the original firmware and enhanced community versions. The whole thing can be found in a GitHub repository, should you wish to have a go yourself.

Long time Hackaday readers will know [Bil Herd] as one of our contributors. If you’re interested in the back story to the series of computers that included the Commodore 16, his book makes for interesting reading.

Using Kirigami Techniques To Make Functional Designs

October 12, 2026 by 2 Comments

The variant of origami called kirigami (‘cut paper’ in Japanese) also starts off with a sheet of paper, but it allows for cutting the paper to increase the number of shapes that you can create. It is this technique that [Matthew Lim] used to create a number of three-dimensional designs that can convert between a flat configuration and some kind of functional object without any bolts, glue or similar. These include everything from a phone grip to a pretty sizeable side table.

The video starts with an interesting demonstration of how to fold an origami crane that has a smaller crane on its back. This is documented in a 1797 book on the many ways to fold a crane, with one of the first known instances where cuts are made in the single sheet of paper, which becomes the second, much smaller crane.

The same book extends that idea into making an origami grid that can fold into a grid of cranes after making a series of cuts. Later this form of origami got the name ‘kirigami’, with the video demonstrating how a few strategic cuts in an original flat shape can make it much more functional, based on scientific papers like this 2024 one by [Liu] et al. on cylindrical origami with tunable mechanical behavior.

For these functional mechanisms a laser cutter and FDM printer are used to prototype and test increasingly more advanced versions of the pop-up mechanism, before moving on to make full-sized furniture using plywood panels and 3D printed hinges. The coolest part about the resulting table is that it can be changed into different configurations, with the mechanism locking into its new position to make a relatively stable new shape.

Even if not immediately practical, these mechanisms provide interesting options for robotics and flat-pack furniture alike, as well as in applications like space exploration where every gram and cubic millimeter of space counts.

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WiFi Router Does Software-Defined Radio

October 12, 2026 by 2 Comments

Perhaps the most famous of software-defined radios is the RTL-SDR, which is very cheap because it’s a digital TV receiver that’s been pressed into service delivering raw I and Q data streams. But the RTL-SDR is certainly not the only chipset that can do this, and today we have a new one.

The MediaTek MT7996 radio chip in the Gemtek W1700K WiFi 7 router can serve as a very competent SDR receiver, and here’s [h0m3us3r] with the code to make it stream over Ethernet to a Linux machine with a web server, through the device’s SoC.

The radio works on the 2.4, 5, and 6 GHz bands, depending upon which version of the device — and thus which radio chip — you have. These may not be entirely useful to many who use lower bands, and given that a similar hack has been found for ESP32 radios on 2.4 GHz it’s likely a demand will arise for a receive up-converter. Until then, you can look at WiFi packets in a waterfall view to your heart’s content.

Since more and more devices now incorporate a radio, we hope that more such undocumented raw streaming modes will be found, and that we’ll see some other new SDRs. Something to look forward to.

The Prusa Core One+ INDX, A Troubled Multi-Extruder Upgrade?

October 12, 2026 by 6 Comments

The Prusa Core One+ INDX is an interesting upgrade to the base FDM printer by Prusa, featuring eight independent extruders – hence the INDX – that in theory should allow for multi-material and multi-color printing with very little purge waste. As [Thomas Sanladerer] found out during his experiences with this printer, there are a lot of issues with this machine, including the ability – or lack thereof – to print with non-Prusa filament.

Although the premise is solid, with a claimed 0.013 grams of purge waste per color or material change along with pretty nice dual-gear Bondtech extruders, the first major hurdle that [Thomas] encountered was that the mandatory calibration sequence on starting a print is designed to only work with Prusa’s own filament and its specific material properties. This resulted in an inability to print with Voxel PLA until [Thomas] removed this sequence manually from the g-code.

This is when [Thomas] found out that the entire print sequence uses the material presets for Prusa’s filament, resulting in a failed print. The results from the manual calibration are also not saved despite the display claiming it does, making this calibration on starting a print absolutely mandatory.

Other issues found are the useless position of the camera as it’s now blocked-off by the INDX hardware, with even manual peeking into the print chamber being heavily obscured by the contraption that holds the extruders. This makes even checking that filament has loaded correctly is borderline impossible, never mind ogling the printing process.

Although there’s a lot to like about this INDX upgrade to the Core One+, the above and other issues discussed in the video make it look somewhat shaky next to competitors like the Bambu Lab H2C and Snapmaker U1, as well as Prusa’s own XL toolchanger printers. During [Thomas]’s print test comparison between the XL and the Core One+ INDX there was no contest that the XL simply works, whereas the INDX even struggles with some Prusa filaments.

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The Hexa-Bouncer May Be The Most Overengineered Thing You See This Week

October 12, 2026 by 4 Comments

Sometimes, you want to build a simple project– the minimum viable product that solves your problem and nothing else. Other times you might be feeling a little extra, and want to use oodles of machined aluminum, six steppers, two cameras, a Teensy and a PC with a GPU just to bounce a ball. That’s the mood behind [T-Kuhn]’s hexa-bouncer, a Stewart Platform on steroids.  You can read all about it on his blog or witness it in action in the video below.  Trust us, really have to see it in action.

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AVIDdrone's winning entry: a helicopter.

DARPA Lift Challenge Won By Helicopter

October 12, 2026 by 19 Comments

America’s mad scientists all have one dream: DARPA money. DARPA, the Defense Advanced Research Projects Agency, regularly throws round sweet, sweet tax dollars to push the envelope on any number of things, leading to such spinoffs as the very network carrying these words to you. Not every DARPA project ends in revolution though– like the latest DARPA Lift Challenge, whose goal was to see the creation of a vehicle that could perform Vertical Take Off And Landing with a payload 4x its own weight. We’ve embedded the ‘look back’ video below.

We hoped for something revolutionary, something bizzare, something really, really cool– and there were absolutely entries on the field that met all of those superlatives. Unfortunately, sometimes conventional designs are the convention for a reason , and the overall winner by AVIDrone, Inc. was just a very well made electric helicopter. One big lift rotor, one little tail rotor– aside from clever details in the solid-state batteries and carbon-fiber construction, it is a totally normal aircraft… albeit one that could lift 3.84x its dry weight, or 112 lb of payload. Interestingly a battery-powered hexrotor drone took home second place with a 3.64:1 lift ratio. Perhaps the big shock was not seeing combustion engines until third place: another helicopter, this time with a turbine engine. So much for energy density!

Some of the other more bizzare– if less performant–entries did get prizes to further their development, so we’ll likely see them back for the 2028 version of the challenge. Some of the concepts visible were covered here on Hackaday, like turning the drone body into a giant lift rotor , so perhaps one of you will have the bright idea that brings home a million in the next round of the contest.

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Your Computer Memory Is A Lie

October 12, 2026 by 38 Comments

When you first learn to program, memory seems pretty straightforward. You have a bunch of bytes, each with an address. If you want to read or write something, you specify the address, and the computer goes to that place and does your bidding. Sure, some addresses might be reserved for hardware or the operating system, but the general idea is simple: memory is a big array of bytes.

Just like we pretend that a wire is a perfect conductor, the big array of memory model used to be a slight twisting of the truth. On a modern computer, however, it is almost entirely a lie. The address you use probably isn’t a physical address. The data you read might not come from RAM at all. Even if it does, it might be sitting in one of several caches. And if you follow the rabbit hole far enough, you discover that your SSD is arguably just another level in the memory hierarchy.

The Need For Speed

The fundamental problem is that processors have gotten much faster than memory. A modern processor can execute several instructions per clock cycle, but accessing ordinary DRAM can take hundreds of cycles. If the processor had to wait for RAM every time it needed data, much of that impressive computing power would go to waste.

The solution is caching. Keep copies of frequently used data in smaller, faster memories closer to the processor. Most modern desktop processors have at least three levels of cache. The L1 cache is tiny but extremely fast, and often split between instructions and data. L2 is larger and somewhat slower, while L3 is even larger and usually slower as well.

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