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”
Today, we think nothing of sticking thousands of pages of documents on a tiny SD card, or just pushing it out to some cloud service. But for decades, this wasn’t possible. Yet companies still generated huge piles of paper. What could be done? The short answer is: microfilm.
However, the long answer is quite a bit more complicated. Microfilm is, technically, a common case of the more generic microform. A microform is a photographically reduced document on film. A bunch of pages on a reel of film is microfilm. If it is on a flat card — usually the size of an index card — that’s microfiche. On top of that, there were a few other incidental formats. Aperture cards were computer punch cards with a bit of microfilm included. Microcards were like microfiche, but printed on cardboard instead of film.
In its heyday, people used specialized cameras, some made to read fanfold computer printer paper, to create microfilm. There were also computer output devices that could create microfilm directly.
Continue reading “Information Density: Microfilm And Microfiche”
We aren’t sure if [Joshua Bellamy] is serious that he wants a laminar flow to water his plants, but there are many places where having a smooth and predictable flow of water is useful or even essential. With his 3D printed adapter, you can produce laminar flow from any garden hose.
If you haven’t heard the term before, laminar flow is to water what a laser is to light. The water moves in parallel tracks with minimal mixing and turbulence. Ensuring laminar flow is often critical to precise flow metering, for example.
This isn’t [Joshua]’s first attempt. He has made a nozzle like this before, but it required a lot of assembly (“more fiddly bits than a Swedish flat-pack sofa” according to the post). Depending on the version, you’ll need various bits of extra hardware in addition to the 3D printed parts. Some versions have drop-in nuts and even an LED. Fiberglass insulation at the inlet diffuses turbulence, and some manual work on the output provided better results. When everything is working, the output of the hose should look like a glass rod, as you can see in the video below.
Air can also have laminar or non-laminar flow. Laminar air flow in a laser cutter’s air assist can make a big difference. If you don’t fancy 3D printing, you could save some drinking straws from your last few hundred trips to the local fast food emporium.
If you have never heard of the Bellmac-32, you aren’t alone. But it is a good bet that most, if not all, of the CPUs in your devices today use technology pioneered by this early 32-bit CPU. The chip was honored with the IEEE Milestone award, and [Willie Jones] explains why in a recent post in Spectrum.
The chip dates from the late 1970s. AT&T’s Bell Labs had a virtual monopoly on phones in the United States, but that was changing, and the government was pressing for divestiture. However, regulators finally allowed Bell to enter the computing market. There was only one problem: everyone else had a huge head start.
There was only one thing to do. There was no point in trying to catch the leaders. Bell decided to leap ahead of the pack. In a time when 8-bit processors were the norm and there were nascent 16-bit processors, they produced a 32-bit processor that ran at a — for the time — snappy 2 MHz.
[Daniel Salião Ferreira] may or may not be a Game of Thrones fan, but he does have a fun demo of the Seebeck effect in the form of a flashlight powered by fire and ice. The basic idea is to use a thermocouple, but — in this case — he uses a Peltier effect cooler.
The Peltier and Seebeck effects are two sides of the same coin: the Peltier effect creates heating and cooling when current flows through a thermoelectric material. In contrast, the Seebeck effect generates a voltage when there is a temperature gradient. While thermocouples do produce voltage this way, they usually have much lower power output and are useless as heat pumps.
It is no secret that we like slide rules around the Hackaday bunker, and among our favorites are the cylindrical slide rules. [Chris Staecker] likes them, too, and recently even 3D printed a version. But spurred by comments on his video, he decided to try something that might be unique: a helical slide rule. You can see how it works in the video below.
With a conventional slide rule, the scale is rotated around a cylinder so that it is the same length as a much longer linear scale. However, this new slide rule bends the entire rule around a cylinder and allows the slide to move, just like a conventional slide rule. If you have a 3D printer, you can make your own.
