Quantum Computing On A Commodore 64 In 200 Lines Of BASIC

July 4, 2023 by 17 Comments

The term ‘quantum computer’ gets usually tossed around in the context of hyper-advanced, state-of-the-art computing devices. But much as how a 19th century mechanical computer, a discrete computer created from individual transistors, and a human being are all computers, the important quantifier is how fast and accurate the system is at the task. This is demonstrated succinctly by [Davide ‘dakk’ Gessa] with 200 lines of BASIC code on a Commodore 64 (GitHub), implementing a range of quantum gates.

Much like a transistor in classical computing, the qubit forms the core of quantum computing, and we have known for a long time that a qubit can be simulated, even on something as mundane as an 8-bit MPU. Ergo [Davide]’s simulations of various quantum gates on a C64, ranging from Pauli-X, Pauli-Y, Pauli-Z, Hadamard, CNOT and SWAP, all using a two-qubit system running on a system that first saw the light of day in the early 1980s.

Naturally, the practical use of simulating a two-qubit system on a general-purpose MPU running at a blistering ~1 MHz is quite limited, but as a teaching tool it’s incredibly accessible and a fun way to introduce people to the world of quantum computing.

3D Audio Imaging With A Phased Array Microphone

July 4, 2023 by 28 Comments

Remember the scene from Blade Runner, where Deckard puts a photograph into a Photo Inspector? The virtual camera can pan and move around the captured scene, pulling out impossible details. It seems that [Ben Wang] discovered how to make that particular trick a reality, but with audio instead of video. The secret sauce isn’t a sophisticated microphone, but a whole bunch of really simple ones. In this case, it’s 192 of them, arranged on long PCBs working as the spokes of a wall-art wheel. Quite the conversation piece.

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2023 Cyberdeck Challenge: Reviving The First Notebook Computer

July 4, 2023 by 7 Comments

At first sight upon seeing [Don]’s HX2023 cyberdeck project one might be sad at the destruction of a retrocomputer, but in fact its classic Epson shell comes from a pile of spare parts left after restoring many other of the classic HX20 notebook computers to working order. The result stays true to the original but gives us so much more in the shape of a Raspberry Pi, and it’s worth cracking it open to see what components make this happen.

The first impression from the pictures is how tidy it all is, with the various USB-based boards contained on a large piece of perfboard spanning the whole case. As well as a USB hub and UPS board there’s an M.2 SSD interface and an audio board, and a DSI color TFT screen neatly fitted in place of the original monochrome item. Finally, there’s an Adafruit keyboard matrix interface board, allowing the use of the Epson’s original keys.

We like this conversion, because it manages to preserve a lot of what the original Epson had that made it great. We’re reminded of a cyberdeck inspired by the other great 8-bit notebook, the TRS-80 model 100.

2023 Hackaday.io Cyberdeck Challenge

Minimal Mods Make Commodity LNBs Work For QO-100 Reception

July 4, 2023 by 15 Comments

A word of advice: If you see an old direct satellite TV dish put out to the curb, grab it before the trash collector does. Like microwave ovens, satellite dishes are an e-waste wonderland, and just throwing them away before taking out the good stuff would be a shame. And with dishes, the good stuff basically amounts to the bit at the end of the arm that contains the feedhorn and low-noise block downconverter (LNB).

But what does one do with such a thing once it’s harvested? Lots of stuff, including modifying it for use with the QO-100 geosynchronous satellite (German link). That’s what [Sebastian Westerhold] and [Celin Matlinski] did with a commodity LNB, although it seems more like something scored on the cheap from one of the usual sources rather than picking through trash. Either way, these LNBs are highly integrated devices that at built specifically for satellite TV use, but with just a little persuasion can be nudged into the K-band to receive the downlink signals from hams using QO-100 as a repeater.

The mods are simple — snipping out the 25 MHz reference crystal on the LNB board and replacing it with a simple LC bandpass filter. This allows the local oscillator on the LNB to be referenced to an external signal generator; when fed with a 25.78 MHz signal, it’s enough to goose the LNB up to 10,490 MHz — right about the downlink frequency. [Sebastian] and [Celin] tested the mods and found that it was easily able to detect the third harmonics of a 3.5-ish GHz signal.

As for testing on actual downlink signals from the satellite, that’ll have to wait. For now, if you’re interested in satellite comms, and you live on the third of the planet covered by QO-100, keep an eye out for those e-waste LNBs and get to work.

Quetzal-1 Satellite Goes Open Source

July 4, 2023 by 30 Comments

Back in 2020, students from Universidad Del Valle De Guatemala (UVG) pulled off a really impressive feat, designing and building a CubeSat that lasted a whopping 211 days in orbit. In addition to telemetry and radio equipment, it carried a black-and-white camera payload.

But it turns out space is hard. The first pictures were solid black or white, with the automatic exposure process failing pretty badly. A pair of good pictures were taken by waiting until the satellite was passing over Guatemala during sunrise or sunset. A hung I2C bus led to battery drain, and the team tried a system reset to clear the hung state. Sadly the craft never came back to life after the reset, likely because of one of the Lithium-Ion battery cells failed completely in the low charge state.

That was 2020, so why are we covering it now? Because the project just released a massive trove of open source design documents, the software that ran on the satellite and ground station, and all the captured telemetry from the flight. It’s the ultimate bootstrap for anyone else designing a CubeSat, and hopefully provides enough clues to avoid some of the same issues.

Even though the mission had problems, it did achieve a lot of milestones, including the first picture of Earth taken by a Central American satellite. Even coming online and making radio contact from orbit to an earthbound station is quite a feat. The team is already looking forward to Quetzal-2, so stay tuned for more!

And if you want the details on the Quetzal-1 design, and what went wrong with the electrical system, both PDF papers have been released. Seeing more open source in space is an encouraging development, and one that should continue to grow as the cost of payloads to orbit continues to fall. We’ve covered the UPSat satellite, the PyCubed framework, and even the RTL-SDR for listening to satellite radio traffic.

Windows 10 The Hard Way: On A Phone

July 4, 2023 by 19 Comments

Sure, there are — or were — Windows phones. But [neozed] wanted something different. An earlier project ran Windows 10 on the Raspberry Pi 4 with some tricks, but those are sometimes hard to come by lately, so the next project was to put one on a Xiaomi PocoPhone F1.

The choice of phone wasn’t an accident. There was enough support and information on the Snapdragon 845 to pull the trick off, and this is one of the phones that looked like it should work. They were pretty inexpensive on eBay and have 128 GB of flash and 6 GB of RAM.

After a few false starts, the phone yielded to fastboot mode. Loading UEFI firmware allows you to re-partition the disks using a PC. With the partitions set up, you must find an ARM Windows 10 image to load. Sounds simple, but as you’ll see in the post, the devil is always in the details. Combined with a USB dock, the end result is a tiny Windows computer. However, it does seem like a lot of work. Even the original poster says: “TL;DR don’t do it… get a used Surface X instead.”

We’ve seen old phones repurposed before, of course. Or, go the other way: start from scratch and build a new phone. We won’t judge, either way.

There’s Always Room For Another Cycle Accurate PC Emulator

July 3, 2023 by 17 Comments

While many Hackaday readers will have their own pieces of classic hardware lovingly preserved, it still remains that most of us get our fix of retro goodness through emulation. And while there are emulators aplenty for almost every platform imaginable, the world of emulation is never complete. Thus we’re happy to encounter a new player in the form of MartyPC, a cycle-accurate 8088 PC emulator written in Rust.

It’s a project that started only in April 2022, but alongside such in-depth processor support it has the full range of PC and XT peripherals including CGA and VGA cards to the extent that it will run even the most hardware-demanding demos. Below the break you can see it running the fiendishly hardware-specific PC demo Area 5150 — thought to be the first time an emulator has managed this task.

If there’s a snag it’s that the releases are so far Windows-only, though it’s claimed that it should also compile on other major platforms. There’s also a WebAssembly version, though sadly the link to it doesn’t work. We look forward to this emulator maturing, because we’re sure it will become a PC standby. After all, not everyone managed to snag one of the recent batch of new hardware.

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