Out in the neon-painted desert of Las Vegas, if you know where to look, you can find an old, 1980s electromechanical horse racing game called Sigma Derby. In this group game, you and several drunk strangers sit around a machine the size of a pool table and bet on tiny horses at 25 cents a throw. There is no skill involved, it’s all chance. This is not that game.
[Alex Kov]’s electromechanical horse racing game is a unicorn compared to Sigma Derby, or at least a zebra. This game takes patience, skill, and cunning. And unlike Sigma Derby, you can easily replicate it at home with a few shakes of the old junk bin. You just need a couple of motors, transistors, electrolytic caps, and some passives.
The idea is simple — advance horse, be first, win prizes — but it’s not that easy. While the switch is unpressed, the circuit charges up a capacitor. Press it and the horse noses forward, draining the cap. There is never enough chooch in the cap to reach the finish line, so the real game is in building up more juice than the other guy, and then staying ahead or overtaking him with the next spurt. Place your bets and catch the action after the break.
A scoreboard would be a great addition to this game. If you want to keep it electromechanical, we have some tote board inspiration for you.
Continue reading “Horse Racing Game Hits Trifecta Of Fun, Skill, And Competition”
Guitar amplifiers are a frequent project, and despite being little more than a simple audio amplifier on paper, they conceal a surprising quantity of variables in search of a particular sound. We’ve seen a lot of them, but never one quite like [Nate Croson]’s CRT TV guitar amplifier. The LM386 doesn’t just drive the speaker, he’s also using it to turn the TV into a crude oscilloscope to form a visualisation of the sound.
The video showing this feat is below the break, and it puts us in a quandary due to being short on technical information. He’s driving the horizontal coils with the TV’s 50 Hz sawtooth field timebase, and the vertical ones with the audio from the LM386. We aren’t sure whether he’s rotated the yoke or whether the connections have been swapped, but the result is certainly impressive.
So given that there’s not quite as much technical detail as we’d like, why has this project captured our interest? Because it serves as a reminder that a CRT TV is a bit more than a useless anachronism, it’s a complex analogue device with significant and unique hacking potential. The older ones in particular provide endless possibilities for modification and circuit bending, and make for a fascinating analogue playground at a very agreeable price. It’s worth pointing out however that some of the voltages involved can make them a hazardous prospect for the unwary hacker. If you’re interested though, take a look at our dive into an older model.
Continue reading “It’s A TV-Scope-Guitar Amplifier!”
There are probably few parents who haven’t watched their kids sitting on the floor, afloat on a sea of LEGO pieces and busily creating, and thought, “If only they could make a living at that.” But time goes on and kids grow up, and parents soon sing the same refrain as the kids sit transfixed by the virtual equivalent of LEGO: Minecraft.
Finding a way to monetize either LEGO or Minecraft is a bit difficult for the young enthusiast; combining both obsessions into a paying proposition would be a dream come true. [Mike Schropp] did it, and this Minecraft-themed LEGO computer case was the result. Intel wanted a LEGO case for their new NUC mini-PC motherboard, and as a sponsor of the Minefaire event, the case needed to be Minecraft themed.
[Mike] chose the block that any Enderman would choose: the basic grass block. Each of the ten cases he made for the show had about 1000 of the smallest LEGO pieces available, to recreate the texture of the grass block in all its faux 8-bit glory. The 4″ x 4″ (10cm x 10cm) 8th Gen NUC board was a great fit for the case, which included slots for ventilation and SD card access, plus pop-out covers to access the board’s ports. It’s not exactly a screamer, but playing Minecraft on a grass block made from LEGO bricks is probably worth the performance hit.
We’ve seen [Mike]’s work a time or two here, most recently with a full-scale LEGO rack-mount server. Our hats off to him for another fun and creative build, and for proving that you’re never too old to LEGO. Or Minecraft.
Proprietary components are the bane of anyone who dares to try and repair their own hardware. Nonstandard sizes, lack of labeling or documentation, and unavailable spare parts are all par for the course. [Jason] was unlucky enough to have an older Dell computer with a broken, and proprietary, cooling fan on it and had to make some interesting modifications to replace it.
The original fan had three wires and was controlled thermostatically, meaning that a small thermistor would speed up the the fan as the temperature increased. Of course, the standard way of controlling CPU fans these days is with PWM, so he built a circuit which essentially converts the PWM signal from the motherboard into a phantom thermistor. It’s even more impressive that it was able to be done with little more than a MOSFET and a Zener diode.
Unfortunately, there was a catch. The circuit only works one way, meaning the fan speed doesn’t get reported to the motherboard and the operating system thinks the fan has failed. But [Jason] simply disabled the warning and washed his hands of that problem. If you don’t want to use a CPU fan at all, you can always just dunk your entire computer in mineral oil.
Decades of post-apocalyptic Hollywood movies have taught us that once all the trappings of our civilisation have been stripped away, it’s going to be kinda cool. We’re all going to wear slightly dusty looking 1980s motorcycling gear, and we’re going to drive really cool cars. Except of course Mad Max is fantasy, and the reality is likely to be unspeakbly grim. The future [Virgil Dupras] is anticipating is not a post-nuclear wasteland though, instead he’s trying to imagine what access to computing might look like in a world where the global supply chain has broken down. His solution is CollapseOS, an operating system designed for resilience and self-replication, that runs upon the minimal hardware of an 8-bit Z80.
It’s a pretty basic operating system so brace yourself if you are expecting a 64-bit fully multithreading kernel. Instead, you’re looking at a kernel, an assembler, and a text editor. One of the stated aims is that it can compile assembly language for a wide range of target CPUs, but it does not make it clear whether this means the OS itself will support those platforms. The self-replication is a fascinating feature though.
It’s an interesting question: what computing hardware would be available to the would-be hacker in a world in which all parts must be scavenged? The Z80 and other processors like it fit the bill admirably in one sense as it is possible to create a working computer using them with fairly minimal tools and knowledge, but we can’t help wondering whether the days when almost any electronic junk pile would contain one are now past. So what other easily accessible computing platforms might be created from post-apocalyptic junk in 2019? Remember, with no laptop and IDE you can’t just put an Arduino bootloader on that ATmega328 you desoldered from an old thermostat. As always the comments are open.
Image: Damicatz [CC BY 2.5].
Cats are among the most popular domesticated creatures, and their penchant for chasing laser pointers is well known. With a pair of felines of his own to look after, [Tobi] set about making a device to help keep them entertained.
The aim of the device is to automate the motion of a laser pointer to make playing with the cats a hands-free operation. A pan-tilt servo mechanism has a low-power red laser pointer fitted, and the assembly is hooked up to a NodeMCU microcontroller. Based on the ESP8266, it allows the system to be controlled remotely over WiFi. Various sweeps can be automatically commanded from a smartphone, or the servo position can be controlled manually.
Test footage confirms that [Tobi’s] pets do indeed find the device to be worthy prey. It’s a popular build for cat lovers, and readily achievable with off-the-shelf parts. If you’ve built your own hardware to keep these proud hunters out of trouble, be sure to hit up the tip line.
Making a natural fiber like wool into something useful like a sweater involves a lot of steps. We might be familiar with shearing the sheep, spinning the wool into yarn, or knitting and weaving, but between shearing and spinning there’s another unfamiliar process you’ll have to go through. Known as carding, it helps align the fibers so they are able to be spun, and of course it requires either an expensive tool, or one you build on your own.
This drum carder is exactly what it sounds like. It uses two drums covered in a metal mesh, spinning at different speeds, which pull the fibers into an orderly shape. Small drum carders like this can run around $600 but with some quality wood and a lathe you can easily make one for a fraction. Making the series of drums is fairly straightforward with a lathe, and from there you need to make sure they are connected with a quality belt or chain and then covered in the appropriate metal mesh.
[kris] notes in the reddit comments section that he’d like for a second version to spin a little faster and be a little more durable, but this is a great working carder nonetheless. From there you’ll want to move on to spinning the wool into yarn, which you can do with either a wheel or an electric motor.
Continue reading “Hand-Made Drum Carder Gets Wool Ready For Spinning”