If you are under a certain age, you probably associate Radio Shack with cellphones. While Radio Shack never gave us access to the variety and economy of parts we have today, they did have one thing that I wish we could get again: P-Box kits. The obvious questions are: What’s a P-Box and why do I want one? But the kit wasn’t to make a P-Box. P-Box was the kind of box the kit came in. It was like a piece of perfboard, but made of plastic, built into a plastic box. So you bought the kit — which might be a radio or a metal detector — opened the box and then built the kit using the box as the chassis.
The perfboard was pretty coarse, too, because the components were all big discrete components. There was at least one that had an IC, but that came premounted on a PC board that you treated like a big component. One of my favorites was a three-transistor regenerative shortwave receiver. In those days, you could pick up a lot of stations on shortwave and it was one of the best ways at the time to learn more about the world.
On the left, you can see a picture of the radio from the 1975 catalog. You might think $7.95 is crazy cheap, but that was at least a tank full of gas or four movie tickets in those days, and most of us didn’t have a lot of money as kids, so you probably saved your allowance for a few weeks, did chores, or delivered papers to make $8.
Continue reading “Retrotechtacular: Remembering Radio Shack P-Box Kits”
If you want to visualize sound waves, you reach for your oscilloscope, right? That wasn’t an option in 1905 so physicist [Heinrich Rubens] came up with another way involving flames. [Luke Guigliano] and [Will Peterson] built one of these tubes — known as a Rubens’ tube — and will show you how you can, too. You can see a video of their results, below. Just in case a flame oscilloscope isn’t enough to attract your interest, they are driving the thing with a theremin for extra nerd points.
The guys show a short flame run and one with tall flames. The results are surprising, especially with the short flames. Of course, the time base is the length of the tube, so that limits your measurements. The tube has many gas jets along the length and with a sound source, the height of the flames correspond to the air pressure from the sound inside the tube.
Continue reading “My Oscilloscope Uses Fire”
What has six wheels and runs on water? Azaris — a new off-road vehicle prototype from Ferox. Azaris has a rocker suspension modeled after the one on the Mars rover. The problem is, linking four drive wheels on a rocker suspension would be a nightmare. The usual solution? Motors directly in the wheels. But Ferrox has a different approach.
The vehicle has a conventional BMW motorcycle engine but instead of driving a wheel, it drives a pump. The pump moves fluid to the wheels where something similar to a water wheel around the diameter of the wheel causes rotation. The fluid is mostly water and the pressure is lower than a conventional hydraulic system. Auto Times has a video of some stills of the prototype and you can see it below. We haven’t actually seen it in motion, unfortunately.
Continue reading “Off Road Vehicle has Six Wheels and Fluid Power”
You have a clean MSDOS system, and you need to write some software for it. What do you do? You could use debug, of course. But there are no labels so while you can get machine code from mnemonics, you’ll still need to figure out the addresses on your own. That wasn’t good enough for [mniip], who created an assembler using mostly batch files. There are a few .COM files and it looks as if the first time you use debug to create those, but there’s also source you can assemble on subsequent builds with the assembler.
Why? We aren’t entirely sure. But it is definitely a hack. The technique sort of reminded us of our own universal cross assembler — sort of.
Continue reading “Bootstrapping An MSDOS Assembler With Batch Files”
Perhaps it is true that if all you have is a hammer every problem you see looks like a nail. When you think of augmented reality (AR), you usually think of something like the poorly-received Google Glass where your phone or computer overlays imagery in your field of vision. Bose isn’t known for video, though, they are known for audio. So perhaps it isn’t surprising that their upcoming (January 2019) AR sunglasses won’t feature video overlays. Instead, the $200 sunglasses will tell you what you are looking at.
The thing hinges on your device knowing your approximate location and the glasses knowing their orientation due to an inertial measuring system. In other words, the glasses — combined with your smart device — know where you are and what you are looking at. Approximately. So at the museum, if you are looking at a piece of art, the glasses could tell you more information about it. There’s a video showing an early prototype from earlier this year, below.
Continue reading “Bose Wants You to Listen Up for Augmented Reality”
It is three weeks after the apocalypse. No zombies yet. But you do need to charge your cell phone. How do you quickly make a wind turbine? If you’ve read this project, you might reach for a few empty water bottles. This educational project might not charge your phone without some extra work, but it does illustrate how to use water bottles to make a workable air scoop for turning a crank and possibly generating electricity.
That takes care of the wind and water aspects, but how did we get solar? According to the post — and we agree it is technically true — wind power is a form of solar power since the wind is driven by temperature differences created by the sun. Technically true!
Continue reading “Generating Power with Wind, Water, and Solar”
Over on GitHub, [ttsiodras] wanted to learn VHDL. So he started with an algorithm to do Mandelbrot sets and moved it to an FPGA. Because of the speed, he was able to accomplish real-time zooming. You can see a video of the results, below.
The FPGA board is a ZestSC1 that has a relatively old Xilinx Spartan 3 chip onboard. Still, it is plenty powerful enough for a task like this.
Continue reading “FPGA used VHDL for Fractals”