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

April 6, 2025 by Al Williams 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 Al Williams 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 Al Williams 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 Al Williams 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.

The Transputer In Your Browser

April 4, 2025 by Al Williams 12 Comments

We remember when the transputer first appeared. Everyone “knew” that it was going to take over everything. Of course, it didn’t. But [Oscar Toledo G.] gives us a taste of what life could have been like with a JavaScript emulator for the transputer, you can try in your browser.

If you don’t recall, the transputer was a groundbreaking CPU architecture made for parallel processing. Instead of giant, powerful CPUs, the transputer had many simple CPUs and a way to chain them all together. Sounds great, but didn’t quite make it. However, you can see the transputer’s influence on CPUs even today.

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A Portable Electronics Workstation

April 4, 2025 by Al Williams 26 Comments

You don’t see them as often as you used to, but it used to be common to see “electronics trainers” which were usually a collection of components and simple equipment combined with a breadboard, often in a little suitcase. We think [Pro Maker_101’s] portable electronics workstation is in the same kind of spirit, and it looks pretty nice.

The device uses a 3D printed case and a custom PC board. There are a number of components, although no breadboard. There is a breakout board for Raspberry Pi GPIO, though. So you could use the screw terminals to connect to an external breadboard. We were thinking you could almost mount one as a sort of lid so it would open up like a book with the breadboard on one side and the electronics on the other. Maybe version two?

One thing we never saw on the old units? An HDMI flat-screen display! We doubt you’d make one exactly like this, of course, but that’s part of the charm. You can mix and match exactly what you want and make the prototyping station of your dreams. Throw in a small portable soldering iron, a handheld scopemeter, and you can hack anywhere.

We’d love to see something like this that was modular. Beats what you could build in 1974.

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Australia’s Silliac Computer

April 3, 2025 by Al Williams 17 Comments

When you think about the dawn of modern computers, you often think about the work done in the UK and the US. But Australia had an early computer scene, too, and [State of Electronics] has done a series of videos about the history of computers down under. The latest episode talks about SILLIAC, a computer similar to ILLIAC built for the University of Sydney in the late 1950s.

How many racks does your computer fill up? SILLIAC had quite a few.

This episode joins earlier episodes about CSIRAC, and WREDAC. The series starts with the CSIR Mark I, which was the first computer in the southern hemisphere.

The -AC computers have a long history. While you often hear statements like, “…in the old days, a computer like this would fill a room,” SILLIAC, in fact, filled three rooms. The three meters of cabinets were in one room, the power supply in another. The third room? Air conditioning. A lot of tubes (valves, in Australia at the time) generate a lot of heat.

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