Author: Al Williams

4296 Articles

Salamander Robot Is Squishy

April 8, 2025 by 7 Comments

If you want to get started in microfluidic robotics, [soiboi soft’s] salamander is probably too complex for a first project. But it is impressive, and we bet you’ll learn something about making this kind of robot in the video below.

The pneumatic muscles are very impressive. They have eight possible positions using three sources of pressure. This seems like one of those things that would have been nearly impossible to fabricate in a home lab a few decades ago and now seems almost trivial. Well, maybe trivial isn’t the right word, but you know what we mean.

The soft robots use layers of microfluidic channels that can be made with a 3D printer. Watching these squishy muscles move in an organic way is fascinating. For right now, the little salamander-like ‘bot has a leash of tubes, but [soiboi] plans to make a self-contained version at some point.

If you want something modular, we’ve seen Lego-like microfluidic blocks. Or, grab the shrinky dinks.

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ASCII To Mainframe

April 8, 2025 by 11 Comments

IBM mainframes are known for very unusual terminals. But IBM made many different things, including the IBM 3151 ASCII terminal, which uses a cartridge to emulate a VT220 terminal. [Norbert Keher] has one and explains in great detail how to connect it to a mainframe.

It had the 3151 personality cartridge for emulating multiple IBM and DEC terminals. However, the terminal would not start until he unplugged it. The old CRT was burned in with messages from an IBM 3745, which helped him work out some of the configuration.

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The Computers Of EPCOT

April 8, 2025 by 8 Comments

Even if you aren’t a Disney fan, you probably know about EPCOT — Experimental Prototype Community of Tomorrow — a Disney attraction that promised a glimpse of the future. [ErnieTech] takes a glimpse at the UNIVAC computer that ran the operation in the 1980s. A lot of schools had UNIVAC 1100-series computers back in those days, so while you don’t hear as much about them as, say, IBM 360s, there are hordes of people who have used the 1100s, even if they don’t remember it.

EPCOT opened in 1982, and the UNIVAC not only ran the attraction but was also visible as part of the exhibit’s ambiance. They even used the Pepper’s Ghost illusion to superimpose a little man on top of the equipment.

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Pluto’s Not A Planet, But It Is A Spectrum Analyzer

April 6, 2025 by 8 Comments

The RTL-SDR dongles get most of the love from people interested in software-defined radio, but the Pluto is also a great option, too. [FromConceptToCircuit] shares code to turn one of these radios into a spectrum analyzer that sweeps up to 6 GHz and down to 100 MHz. You can see a video of how it works below.

While it may seem that 100 MHz is a bit limiting, there’s plenty of activity in that range, including WiFi, Bluetooth, radio systems, both commercial and amateur, and even cell phones.

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Emulating IPhone On QEMU

April 6, 2025 by 4 Comments

[Georges Gagnerot] has been trying to emulate iOS and run iPhone software in a virtual environment. There were a few choices, and qemu-t8030 had a number of interesting features that you can check out in his post.

The project requires a patched QEMU, and [Georges] did some basic jailbreaking techniques. The real problem, of course, was not having the Apple Silicon GPU. Older versions of iOS let you select software rendering, but that option is gone on newer versions. However, it was possible to patch the phone to still use software rendering. There are still apps that directly use Metal or OpenGL that won’t run, but that’s another problem.

There is a plan to explore forwarding GPU calls to a real device. However, that seems difficult so it will have to wait for now.

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Inside An Edison Phonograph

April 5, 2025 by 14 Comments

If you think of records as platters, you are of a certain age. If you don’t remember records at all, you are even younger. But there was a time when audio records were not flat — they were drums, which was how the original Edison phonograph worked. [Our Own Devices] did a video earlier showing one of these devices, but since it was in a museum, he didn’t get to open it up. Lucky for us, he now has one of his own, and we get to see inside in the video below.

Ironically, Edison was deaf yet still invented the phonograph. While he did create the working phonograph — his self-identified most important invention — the original invention wasn’t commercially viable. You could record and playback audio on tin foil wrapped around a drum. But you couldn’t remove the foil without destroying it.

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A Look Inside MacPaint

April 5, 2025 by 28 Comments

Usually when we talk about retrocomputing, we want to look at — and in — some old hardware. But [Z→Z] has a different approach: dissecting MacPaint, the Apple drawing program from the 1980s.

While the program looks antiquated by today’s standards, it was pretty hot stuff back in the day. Things we take for granted today were big deals at the time. For example, being able to erase a part of something you drew prompted applause at an early public demo.

We enjoyed the way the program was tested, too. A software “monkey” was made to type keys, move things, and click menus randomly. The teardown continues with a look inside the Pascal and assembly code with interesting algorithms like how the code would fill an area with color.

The program has been called “beautifully organized,” and [Z→Z] examines that assertion. Maybe the brilliance of it has been overstated, but it did work and it did influence many computer graphics programs over the years.

We love digging through old source code. Even old games. If you do your own teardowns, be sure to send us a tip.