An Amiga 2000 on a carpet floor

Amiga, Interrupted: A Fresh Take On Amiga OS

Serena OS is not just another operating system—it’s a playground for hackers, tinkerers, and Amiga enthusiasts pushing vintage hardware to new limits. Born from modern design principles and featuring pervasive preemptive concurrency and multi-user support, [dplanitzer]’s Serena OS is far from ordinary.

Running on Amiga systems with a 68030 or better CPU, it challenges traditional OS concepts by ditching threads in favor of dispatch queues, akin to Apple’s Grand Central Dispatch. The result? A dynamic, flexible kernel that combines forward-thinking design with retro charm.

The real innovation in Serena is its kernel, which uses a virtual processor concept to manage system resources efficiently. Instead of threads, Serena dynamically adjusts a pool of virtual processors based on dispatch queue needs, ensuring tasks are executed with precision and speed. Interrupt handling is also unique: interrupts are converted into semaphore signals, allowing the code to handle these signals at its convenience without missing any, making hardware interactions more controlled, especially where timing is critical.

For Amiga enthusiasts already customizing their setups, Serena OS offers new possibilities. It shares some spirit with projects like AROS (Amiga Research Operating System) but adds its own twist with object-oriented design and cross-platform goals. Whether you’re developing software for your classic Amiga or exploring new hardware interfaces, Serena OS provides a robust and adaptable foundation.

A very wide beige laptop sits on a wooden table. A hand manipulates a teal ball in a semicircle attached to the right sided of the device. The track ball and hand are outlined in white.

A Trackball Retro Laptop

While track pads and mice dominate the pointing device landscape today, there was a time when track balls were a major part of the scene. In order to really sell the retro chops of his portable computer, [Ominous Industries] designed a clip-on style track ball for his retro Raspberry Pi laptop.

Starting with a half circle shape, he designed the enclosure in Fusion360 to house the guts of a USB trackball. Using the pattern along a path feature of the software, he was able to mimic the groovy texture of the main device on the trackball itself. Flexures in the top of the track ball case with pads glued on actuate the buttons.

We appreciate the honesty of the cuts showing how often the Pi can get grumpy at the extra wide display in this video as well as the previous issues during the laptop build. The bezel around the screen is particularly interesting, being affixed with magnets for easy access when needing to work on the screen.

Retro portables are having a moment. We just covered the Pi Portable 84 and previously saw one inspired by the GRiD Compass . If you’re more interested in trackballs, maybe give this trackball ring or the Ploopy trackball a look?

Continue reading “A Trackball Retro Laptop”

Cost-Optimized Raspberry Pi 5 Released With 2 GB RAM And D0 Stepping

When the Raspberry Pi 5 SBC was released last year, it came in 4 and 8 GB RAM variants, which currently retail from around $80 USD and €90 for the 8 GB variant to $60 and €65 for the 4 GB variant. Now Raspberry Pi has announced the launch of a third Raspberry Pi 5 variant: a 2 GB version which also features a new stepping of the BCM2712 SoC. This would sell for about $50 USD and feature the D0 stepping that purportedly strips out a lot of the ‘dark silicon’ that is not used on the SBC.

These unused die features are likely due to the Broadcom SoCs used on Raspberry Pi SBCs being effectively recycled set-top box SoCs and similar. This means that some features that make sense in a set-top box or such do not make sense for a general-purpose SBC, but still take up die space and increase the manufacturing defect rate. The D0 stepping thus would seem to be based around an optimized die, with as only possible negative being a higher power density due to a (probably) smaller die, making active cooling even more important.

As for whether 2 GB is enough for your purposes depends on your use case, but knocking $10 off the price of an RPi 5 could be worth it for some. Perhaps more interesting is that this same D0 stepping of the SoC is likely to make it to the other RAM variants as well. We’re awaiting benchmarks to see what the practical difference is between the current C1 and new D0 steppings.

Thanks to [Mark Stevens] for the tip.

Historical Microsoft And Apple Artifacts Among First Christie’s Auction Of Living Computers Museum

Recently the Christie’s auction house released the list of items that would be going up for sale as part of the first lot of Living Computer Museum items, under the banner “Gen One: Innovations from the Paul G. Allen Collection”. One auction covers many ‘firsts’ in the history of computing,  including a range of computers like an Apple 1, and a PDP-10, as well as early Microsoft memos and code printouts. The other auctions include such items like a Gemini Spacesuit as worn by [Ed White] and a signed 1939 letter from [Albert Einstein] to [US President Roosevelt] on the discovery by the Germans of a fissionable form of uranium from which a nuclear weapon could be constructed.

We previously reported on this auction when it was first announced in June of this year. At the time many were saddened at seeing the only computer history and its related educational facilities vanish, and there were worries among those who had donated items to the museum what would happen to these now that the museum’s inventory was being put up for sale. As these donations tend to be unconditional, the museum is free to do with the item as they see fit, but ‘being sold at auction’ to probably a private collector was likely not on their mind when filling in the donation form.

As the first auctions kick off in a few days we will just have to wait and see where the museum’s inventory ends up at, but it seems likely that many of these items which were publicly viewable will now be scattered across the globe in private collections.

Top image: A roughly 180° panorama of the “conditioned” room of the Living Computer Museum, Seattle, Washington, USA. Taken in 2014. (Credit: Joe Mabel)

Portable Router Build: Finding An LTE Modem

Ever want your project equipped with a cellular interface for a data uplink? Hop in, I have been hacking on this for a fair bit! As you might remember, I’m building a router, I told you about how I picked its CPU board, and learned some lessons from me daily-driving it as a for a bit – that prototype has let me learn about the kind of extra hardware this router needs.

Here, let’s talk about LTE modems for high data throughput, finding antennas to make it all work, and give you a few tips that should generally help out.  I’d like to outline a path that increases your chances of finding a modem working for you wonderfully – the devices that we build, should be reliable.

Narrowing It Down

If you look at the LTE modem selection, you might be a little overwhelmed: Simcom, Qualcomm, uBlox, Sierra, Telit, and a good few other manufacturers package baseband chipsets into modules and adjust the chipset-maker-provided firmware. The modems will be available in many different packages, too, many of them solderable, and usually, they will be available on mPCIe cards too. If you want to get a modem for data connections for a project, I argue that you should go for mPCIe cards first, and here’s why.

Continue reading “Portable Router Build: Finding An LTE Modem”

Get More Freedom With This Guitar Pedal

When the electric guitar was first produced in the 1930s, there was some skepticism among musicians as to whether or not this instrument would have lasting impact or be a flash-in-the-pan novelty. Since this was more than a decade before the invention of the transistor, it would have been hard then to imagine the possibilities that a musician nowadays would have with modern technology to shape the sound of an instrument like this. People are still innovating in this space as well as new technology appears, like [Gary Rigg] who has added a few extra degrees of freedom to a guitar effects pedal.

A traditional expression pedal, like a wah-wah pedal, uses a single motion to change an aspect of the sound of the guitar, and is generally controlled with the musician’s foot. [Gary]’s pedal, on the other hand, can be manipulated in three different ways to control separate elements of the instrument’s sound. It can be pitched forward and back like a normal effects pedal, but also rolled side-to-side and twisted around its yaw axis. The pedal has a built-in IMU to measure the various position changes of the pedal, which is then translated by an RP2040 microcontroller to a MIDI signal which controls the three different aspects of the sound digitally.

While the yaw motion might be difficult for a guitarist to create with their foot while playing, the idea for this pedal is still excellent. Adding in a few more degrees of freedom gives the musician more immediate control over the sound of their instrument and opens up ways of playing that might not be possible or easy with multiple pedals, with the MIDI allowing for versatility that might not be available in many analog effects pedals. Not every pedal needs MIDI though; with the help of a Teensy this digital guitar pedal has all its effects built into a self-contained package.

Continue reading “Get More Freedom With This Guitar Pedal”

This Is Not A Laptop, It’s A KVM Combo

A spare monitor and keyboard are handy things to have around, but they’re a bit of a hassle. They are useful for hardware development, plugging in to headless servers, or firing up a Raspberry Pi or similar single-board computer (SBC). If that’s something you do and portability and storage space are important to you, then you may be interested in the CrowView Note.

I got an opportunity to test and provide feedback on an early version of this unusual device, which is functionally a portable spare monitor plus keyboard (and touchpad) without the bulk and extra cables. Heck, it’s even giving me ideas as the guts of a Cyberdeck build. Let’s take a look.

What It Is

It really looks like a laptop, but it’s actually a 14″ 1920 x 1280 monitor and USB keyboard in a laptop form factor.

There is also an integrated trackpad, speakers and mic, and a rechargeable battery. That makes it capable of providing its own power, and it can even function as a power bank in a pinch. There’s an HDMI input on one side, and on the other is a full-featured USB-C port that accepts video input via the DisplayPort altmode.

Pictured here is a Raspberry Pi 5 with optional PCB adapter to eliminate cables. The three ports (HDMI in, USB-C 5 V out, and USB-A for peripherals) provide all the board needs.

The CrowView Note is a pretty useful device for a workbench where one is often plugging hardware in for development or testing, because there’s no need to manage a separate monitor, keyboard, and mouse.

It is not a laptop, but attaching an SBC like a Raspberry Pi makes it act like one. The three ports conveniently located on the left-hand side (HDMI in, USB-C out for power to the SBC, and USB-A in for peripherals like keyboard and trackpad) are all that are needed in this case. Elecrow offers a “cable eliminator” PCB adapters to make the process of connecting a Raspberry Pi 5 or a Jetson Nano as simple as possible. The result is something that looks and works just like a laptop.

Well, almost. The SBC will still be a separate piece of hardware, whether connected by cables or by one of Elecrow’s PCB adapters. The result is OK for bench work, but especially in the case of the PCB adapter, not particularly rugged. Still, it’s a nice option and makes working on such boards convenient and cable-free.

Continue reading “This Is Not A Laptop, It’s A KVM Combo”