WoWMIPS: A MIPS Emulator For Windows Applications

February 17, 2024 by 12 Comments

When Windows NT originally launched it had ports to a wide variety of platforms, ranging from Intel’s x86 and i860 to DEC’s Alpha as well as the MIPS architecture. Running Windows applications written for many of these platforms is a bit tricky these days, which [x86matthew] saw as a good reason to write a MIPS emulator. This isn’t just any old emulator, though. It maps 32-bit Windows applications targeted at the MIPS R4000 CPU to an x86 CPU instead. Since both platforms run in a little-endian, 32-bit mode, this theoretically should be a walk in the park.

The use of the Windows PE executable format is also the same, so the first task was to figure out how to load the MIPS PE binary in a way that made sense for an x86 platform. This involved some reverse-engineering of the MIPS ntdll.dll file to figure out how relocations on that platform were handled. Following this, the mapping of the instructions of the R4000 CPU to the (CISC) x86 ISA was pretty easy. Only Floating Point Unit (FPU) support was left as a future challenge. Memory access was left as direct access, meaning no sandboxing or isolation, for simplicity’s sake.

The final task was mapping the native API calls, which call almost directly into the underlying host Windows OS’s API, with a bit of glue logic. With all of this done, Windows NT applications originally written for 1990s MIPS ran just fine on a modern-day x86_64 PC running Windows — as long as you don’t need an FPU (for now).

Salvaged Meter Movements Really Pop In This DIY VU Meter Bridge

February 17, 2024 by 3 Comments

If you’re going to build a nice VU meter bridge for the recording studio, the first thing you need is a nice pair of VU meters. But lest you think it’s as easy as putting some meters into a nice box and calling it a day, think again.

This project comes to us from [Frank Olson], whose projects usually incorporate wood as part of the mechanism, as with his famous wooden ribbon microphone. This build does indeed use wood, and to excellent effect, but only in the project’s final enclosure. Before that, [Frank] had salvaged a pair of good-looking moving coil meters from an old tape recorder. He muddled through some ideas before settling on a design. A NE5532 dual-channel audio buffer module is used as a preamp, with each channel feeding into a bridge rectifier before heading to the meter. Wisely, [Frank] chose to illuminate the meters with their existing incandescent bulbs, so a small DC-DC supply was added to provide the necessary 8 volts.

As for the enclosure, that’s where [Frank]’s experience working with veneers paid off. He chose mahogany, carefully cut all the pieces to shape with a knife, and glued it all up with CA glue — at least we assume it was CA; based on previous efforts, he uses a lot of the stuff. The tung oil finish looks fantastic, and the completed build aesthetic looks great! The video below shows it all.

If you need some backstory on the VU meter, we can help with that.

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Sneaky Fix Gets Simon Back Up And Running

February 16, 2024 by 6 Comments

Simon was a cutting-edge “computer controlled game” when it launched back in 1978. It would flash out a pattern of ever-increasing length and you had to copy it if you didn’t want to lose. The name, obviously inspired by the traditional folk game of Simon Says. [Robert] recently found an original vintage Simon game, but it had been non-functional for many years. However, with some astute analysis and repair, he was able to get it working again.

Upon powering the unit up, the best [Robert] could get out of it was some flickering of the lights, nothing more. It wouldn’t start a game or respond to button presses. Eventually, probing around showed [Robert] that the TMS1000 microcontroller wasn’t running properly.  It seemed to concern the connection to the “Game Mode” selector switch. Thanks to a fault and the multiplexed layout of the controls, it was appearing to the microcontroller that a button was always pressed at all times.

The solution [Robert] landed on was to separate out the signal from the Game Mode switch by socketing the TMS1000 and lifting the relevant pin. . The signal was then wired back up to the chip via diodes so that it wouldn’t interfere with the other outputs and inputs on the chip used to read the other buttons. This meant that the unit was locked into the single main game mode, but it did get it operational again.

It may not be a complete repair, but it nonetheless saved this unit from complete failure. Failing a repair of your own unit, you can always build one with modern hardware instead. Video after the break.

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Bioluminescent Glowing Petunias Are Now A Thing

February 16, 2024 by 45 Comments

Outside of the depths of the ocean, or cartoons, we’re not typically accustomed to plant life glowing or otherwise generating its own light. However, science is helping to change all that. Now, you can order some bioluminescent plants of your very own from Light Bio.

Light Bio is a startup company working in the synthetic biology space. It’s not content to simply pursue research behind closed doors, and is now sharing its work with the public. It has announced it plans to start selling petunias to U.S. customers which literally glow with the magic of bioluminescence.

Petunias don’t normally glow, but with some modifications, it turns out they can be convinced to. It took a large team of 26 scientists to figure out how to boost bioluminescence in plants, by isolating and optimizing genes sourced from various glowing mushroom species.

The plants will be available from April, with Light Bio planning to sell them as “Firefly Petunias.” It might sound like scary sci-fi tech, but the USDA has apparently already signed off on Light Bio selling these to the public.

Something’s been bothering me, though. It’s at the edge of my memory… I think my old housemate played bass for Glowing Petunias back in 2015. Something like that, anyway… video after the break.

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A white man with red hair in pigtails under a brown cap holds an axe with a black head and wooden handle. The axe has a rectangular box welded onto the back side of its trapezoidal head.

Deadblow Axe Splits Wood With Minimal Rebound

February 16, 2024 by 17 Comments

Dead-blow hammers are well-known in the construction industry for minimizing rebound. [Jacob Fischer] is on a mission to bring this concept to splitting axes.

Over the course of several months, [Fischer] has been working on adding a dead-blow to a splitting axe. This fifth iteration uses a custom-forged head from blacksmith [Todd Elder] with a dead-blow box welded to the poll. The combination of the head geometry and the dead-blow distributing the delivery of force seems to result in a very effective splitting axe.

The dead-blow portion of the axe is a steel box filled with lead (Pb) BBs. Since the BBs are trailing the axe head within the box, the force from the BBs is delivered later than the initial impact of the steel axe head onto the block of wood, allowing the full force of the blow to be spread out over more time. Dead-blow hammers typically use polymers to further absorb any rebound energy, so there is some limit to the extent rebound can be reduced as seen in the testing portion of the video.

Looking for other ways to split wood? How about this cross-bladed axe or maybe a log splitter or two? If you’re curious about how they used to make axes in the old days, we’ve got you covered there too.

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Sonolithography With The Raspberry Pi Pico

February 16, 2024 by 5 Comments

You can do some wild things with sound waves, such as annoy your neighbours or convince other road users to move out of your way. Or, if you get into sonolithography like [Oliver Child] has, you can make some wild patterns with ultrasound.

Sonolithography is a method of patterning materials on to a surface using finely-controlled sound waves. To achieve this, [Oliver] created a circular array of sixteen ultrasonic transducers controlled via shift registers and gate driver ICs, under the command of a Raspberry Pi Pico. He then created an app for controlling the transducer array via an attached computer with a GUI interface. It allows the phase and amplitude of each element of the array to be controlled to create different patterns.

Creating a pattern is then a simple matter of placing the array on a surface, firing it up in a given drive mode, and then atomising some kind of dye or other material to visualize the pattern of the acoustic waves.

It could be a useful tool for studying the interactions of ultrasonic waves, or it could just be a way to make neat patterns in ink and dye if that’s what you’re into. [Oliver] notes the techniques of sonolithography could also have implications in biology or fabrication in future, as well. If you found this interesting, you might like to study up on ultrasonic levitation, too!

Change The Jingle In Your Makita Charger Because You Can

February 16, 2024 by 20 Comments

Lots of things beep these days. Washing machines, microwaves, fridge — even drill battery chargers. If you’re on Team Makita, it turns out you can actually change the melody of your charger’s beep, thanks to a project from [Real-Time-Kodi].

The hack is for the Makita DR18RC charger, and the implementation of the hack is kind of amusing. [Real-Time-Kodi] starts by cutting the trace to the buzzer inside the charger. Then, an Arduino is installed inside the charger, hooked up to the buzzer itself and the original line that was controlling it. When it detects the charger trying to activate the buzzer, it uses this as a trigger to play its own melody on the charger instead. The Arduino also monitors the LEDs on the charger in order to determine the current charge state, and play the appropriate jingle for the situation.

It’s an amusing hack, and one that could certainly confuse the heck out of anyone expecting the regular tones out of their Makita charger. It also shows that the simple ways work, too — there was no need to dump any firmware or decompile any code.

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