[Bhuvanmakes] says that he has the simplest open source photobioreactor. Is it? Since it is the only photobioreactor we are aware of, we’ll assume that it is. According to the post, other designs are either difficult to recreate since they require PC boards, sensors, and significant coding.
This project uses no microcontroller, so it has no coding. It also has no sensors. The device is essentially an acrylic tube with an air pump and some LEDs.
I often ask people: What’s the most important thing you need to have a successful fishing trip? I get a lot of different answers about bait, equipment, and boats. Some people tell me beer. But the best answer, in my opinion, is fish. Without fish, you are sure to come home empty-handed.
On a recent visit to Bletchley Park, I thought about this and how it relates to World War II codebreaking. All the computers and smart people in the world won’t help you decode messages if you don’t already have the messages. So while Alan Turing and the codebreakers at Bletchley are well-known, at least in our circles, fewer people know about Arkley View.
The problem was apparent to the British. The Axis powers were sending lots of radio traffic. It would take a literal army of radio operators to record it all. Colonel Adrian Simpson sent a report to the director of MI5 in 1938 explaining that the three listening stations were not enough. The proposal was to build a network of volunteers to handle radio traffic interception.
That was the start of the Radio Security Service (RSS), which started operating out of some unused cells at a prison in London. The volunteers? Experienced ham radio operators who used their own equipment, at first, with the particular goal of intercepting transmissions from enemy agents on home soil.
At the start of the war, ham operators had their transmitters impounded. However, they still had their receivers and, of course, could all read Morse code. Further, they were probably accustomed to pulling out Morse code messages under challenging radio conditions.
Over time, this volunteer army of hams would swell to about 1,500 members. The RSS also supplied some radio gear to help in the task. MI5 checked each potential member, and the local police would visit to ensure the applicant was trustworthy. Keep in mind that radio intercepts were also done by servicemen and women (especially women) although many of them were engaged in reporting on voice communication or military communications.
Some people love tools in their browsers. Others hate them. We certainly do like to see just how far people can push the browser and version 0.6 of CHILI3D, a browser-based CAD program, certainly pushes.
If you click the link, you might want to find the top right corner to change the language (although a few messages stubbornly refuse to use English). From there, click New Document and you’ll see an impressive slate of features in the menus and toolbars.
The export button is one of those stubborn features. If you draw something and select export, you’ll see a dialog in Chinese. Translated it has the title: Select and a checkmark for “Determined” and a red X for “Cancelled.” If you select some things in the drawing and click the green checkmark, it will export a brep file. That file format is common with CAD programs, but you’ll need to convert, probably, if you want to 3D print your design.
The project’s GitHub repository shows an impressive slate of features, but also notes that things are changing as this is alpha software. The CAD kernel is a common one brought in via WebAssembly, so there shouldn’t be many simple bugs involving geometry.
We’ve seen a number of browser-based tools that do some kind of CAD. CADmium is a recent entry into the list. Or, stick with OpenSCAD. We sometimes go low-tech for schematics.
They say that if you let a million monkeys type on a million typewriters, they will eventually write the works of Shakespeare. While not quite the same thing [bbenchoff] (why does that sound familiar?), spent some computing cycles to generate random data and, via heuristics, find valid Atari 2600 “games” in the data.
As you might expect, the games aren’t going to be things you want to play all day long. In fact, they are more like demos. However, there are a number of interesting programs, considering they were just randomly generated.
It is a good bet that if most scientists and engineers were honest, they would most like to leave something behind that future generations would remember. While Marie Curie met that standard — she was the first woman to win the Nobel prize because of her work with radioactivity, and a unit of radioactivity (yes, we know — not the SI unit) is a Curie. However, Curie also left something else behind inadvertently: radioactive residue. As the BBC explains, science detectives are retracing her steps and facing some difficult decisions about what to do with contaminated historical artifacts.
Marie was born in Poland and worked in Paris. Much of the lab she shared with her husband is contaminated with radioactive material transferred by the Curies’ handling of things like radium with their bare hands.
Until recently, hobby-grade digital oscilloscopes were mostly, at most, 8-bit sampling. However, newer devices offer 12-bit conversion. Does it matter? Depends. [Kiss Analog] shows where a 12-bit scope may outperform an 8-bit one.
It may seem obvious, of course. When you store data in 8-bit resolution and zoom in on it, you simply have less resolution. However, seeing the difference on real data is enlightening.
Continue reading “Two Bits, Four Bits, A Twelve-bit Oscilloscope”
You might wonder why you’d repair a calculator when you can pick up a new one for a buck. [Tech Tangents] though has some old Sony calculators that used Nixie tubes, including one from the 1960s. Two of his recent finds of Sony SOBAX calculators need repair, and we think you’ll agree that restoring these historical calculators is well worth the effort. Does your calculator have a carrying handle? We didn’t think so. Check out the video below to see what that looks like.
The devices don’t even use modern ICs. Inside, there are modules of discrete parts encapsulated in epoxy. There isn’t even RAM inside, but there is a delay line memory, although it is marked “unrepairable.”
There is some interesting history about this line of calculators, and the video covers that. Apparently, the whole line of early calculators grew out of an engineer’s personal project to use transistors that were scrapped because they didn’t meet the specifications for whatever application that used them.
The handle isn’t just cosmetic. You could get an external battery pack if you really wanted a very heavy — about 14 pounds (6.3 kilograms) — and large portable calculator. We are sure the $1,000 retail price tag didn’t include a battery.
These machines are beautiful, and it is fun to see the construction of these old devices. You might think our favorite calculator is based on Star Trek. As much as we do like that, we still think the HP-41C might be the best calculator ever made, even in emulation.
Continue reading “Repairing Vintage Sony Luggable Calculators”
