Pico-mac-nano Fits Working Macintosh On Barbie’s Desk

May 26, 2025 by Tyler August 13 Comments

Have you ever looked in a doll house and said “I wish those dolls had a scale replica of a 1984 Macintosh 128K that could be operated by USB?” — well, us neither, but [Nick Gillard] gives us the option with his 63mm tall Pico-mac-nano project.

As you might imagine, this project got its start with the RP2040-based Pico Mac project by [Matt Evans], which we covered

The collector’s edition will come with a lovely box, but what’s in it is still open source so you can make your own.

before. [Nick] saw that, built it, and was delighted by it enough to think that if the Mac could run on such tiny hardware, how small could build a fully-usable replica Mac? The answer was 63 mm tall– at 5.5:1, that’s technically under the 6:1 scale that Barbie operates on, but if we had such a dollhouse we’d absolutely put one of these in it. (You just know Barbie’s an Apple kind of girl.)

The size was driven by the screen, which is a 2″ TFT panel with 480 x 640 pixel native resolution. Here [Nick] cheats a tiny bit– rather than trying to rewrite the PicoMac to output 640 x 480 and rotate the screen, he keeps the screen in portrait mode and drives it at 480 x 342 px. Sure, it’s not a pixel-perfect output, but no LCD is going to be a perfect stand in for a CRT, and who is going to notice 32 pixels on a 2″ screen? Regardless, that set the height of the computer, which is built around the portrait display. A highly detailed, and to our eyes, accurate replica of the original Macintosh case was printed to fit the LCD, coming in at the aforementioned 63mm tall.

Unfortunately this means the floppy drive could not be used for micro SD access– there is an SD card reader on this unit, but it’s on the back, along with a USB-C port, which is roughly where the mouse and keyboard ports are supposed to be, which is a lovely detail. Also delightful is the choice of a CR2 lithium battery for power, which is a form factor that will look just a bit familiar if you’ve been inside one of these old Macs.

[Nick] has posted the 3D designs and modified pico mac firmware to a GitHub repository, but if you’re looking for a charming desk ornament and don’t have the time to build your own, he will also be selling these (both kits and fully assembled units) via 1bitrainbow, which is the most delightfully retro web store we’ve seen of late.

If Classic MacOS isn’t good enough for you, how about linux? You won’t enjoy it as much, but it will run on the RP2040.

A graph of download speeds is shown, with two triangular spikes and declines. Above the graph, the label “8 MB/s” is shown.

A Quick Introduction To TCP Congestion Control

May 25, 2025 by Aaron Beckendorf 11 Comments

It’s hard to imagine now, but in the mid-1980s, the Internet came close to collapsing due to the number of users congesting its networks. Computers would request packets as quickly as they could, and when a router failed to process a packet in time, the transmitting computer would immediately request it again. This tended to result in an unintentional denial-of-service, and was degrading performance significantly. [Navek]’s recent video goes over TCP congestion control, the solution to this problem which allows our much larger modern internet to work.

In a 1987 paper, Van Jacobson described a method to restrain congestion: in a TCP connection, each side of the exchange estimates how much data it can have in transit (sent, but not yet acknowledged) at any given time. The sender and receiver exchange their estimates, and use the smaller estimate as the congestion window. Every time a packet is successfully delivered across the connection, the size of the window doubles.

Once packets start dropping, the sender and receiver divide the size of the window, then slowly and linearly ramp up the size of the window until it again starts dropping packets. This is called additive increase/multiplicative decrease, and the overall result is that the size of the window hovers somewhere around the limit. Any time congestion starts to occur, the computers back off. One way to visualize this is to look at a graph of download speed: the process of periodically hitting and cutting back from the congestion limit tends to create a sawtooth wave.

[Navek] notes that this algorithm has rather harsh behavior, and that there are new algorithms that both recover faster from hitting the congestion limit and take longer to reach it. The overall concept, though, remains in widespread use.

If you’re interested in reading more, we’ve previously covered network congestion control in more detail. We’ve also covered [Navek]’s previous video on IPV5. Continue reading “A Quick Introduction To TCP Congestion Control” →

LED Matrix Built For M.2 Interface

May 24, 2025 by Lewin Day 8 Comments

The M.2 slot is usually used for solid-state storage devices. However, [bitluni] had another fun idea for how to use the interface. He built an M.2 compatible LED matrix that adds a little light to your motherboard.

[bitluni] built a web tool for sending images to the matrix.

[bitluni] noted that the M.2 interface is remarkably flexible, able to offer everything from SATA connections to USB, PCI Express, and more. For this project, he elected to rely on PCI Express communication, using a WCH CH382 chip to translate from that interface to regular old serial communication.

He then hooked up the serial interface to a CH32V208 microcontroller, which was tasked with driving a 12×20 monochrome LED matrix. Even better, he was even able to set the microcontroller up to make it programmable upon first plugging it into a machine, thanks to its bootloader supporting serial programming out of the box. Some teething issues required rework and modification, but soon enough, [bitluni] had the LEDs blinking with the best of them. He then built a web-based drawing tool that could send artwork over serial direct to the matrix.

While most of us are using our M.2 slots for more traditional devices, it’s neat to see this build leverage them for another use. We could imagine displays like this becoming a neat little add-on to a blingy computer build for those with a slot or two to spare. Meanwhile, if you want to learn more about M.2, we’ve dived into the topic before.

Continue reading “LED Matrix Built For M.2 Interface” →

C64 on desk with NFC TeensyROM and game token

TeensyROM NFC Game Loading On The C64

May 23, 2025 by Heidi Ulrich 6 Comments

When retro computing nostalgia meets modern wireless wizardry, you get a near-magical tap-to-load experience. It’ll turn your Commodore 64 into a console-like system, complete with physical game cards. Inspired by TapTo for MiSTer, this latest hack brings NFC magic to real hardware using the TeensyROM. It’s been out there for a while, but it might not have caught your attention as of yet. Developed by [Sensorium] and showcased by YouTuber [StatMat], this project is a tactile, techie love letter to the past.

At the heart of it is the TeensyROM cartridge, which – thanks to some clever firmware modding – now supports reading NFC tags. These are writable NTag215 cards storing the path to game files on the Teensy’s SD card. Tap a tag to the NFC reader, and the TeensyROM boots your game. No need to fumble with LOAD “*”,8,1. That’s not only cool, it’s convenient – especially for retro demo setups.

What truly sets this apart is the reintroduction of physical tokens. Each game lives on its own custom-designed card, styled after PC Engine HuCards or printed with holographic vinyl. It’s a tangible, collectible gimmick that echoes the golden days of floppies and cartridges – but with 2020s tech underneath. Watch it here.

Continue reading “TeensyROM NFC Game Loading On The C64” →

Running DOOM On An Atari ST

May 22, 2025 by Heidi Ulrich 27 Comments

If you grew up with a beige Atari ST on your desk and a faint feeling of being left out once Doom dropped in 1993, brace yourself — the ST strikes back. Thanks to [indyjonas]’s incredible hack, the world now has a working port of DOOM for the Atari STe, and yes — it runs. It’s called STDOOM, and even though it needs a bit of acceleration or emulation to perform, it’s still an astonishing feat of retro-software necromancy.

[indyjonas] did more than just recompile and run: he stripped out chunks of PC-centric code, bent GCC to his will (cheers to Thorsten Otto’s port), and shoehorned Doom into a machine never meant to handle it. That brings us a version that runs on a stock machine with 4MB RAM, in native ST graphics modes, including a dithered 16-colour mode that looks way cooler than it should. The emotional punch? This is a love letter to the 13-year-old Jonas who watched Doom from the sidelines while his ST chugged along faithfully. A lot of us were that kid.

Sound is still missing, and original 8MHz hardware won’t give you fluid gameplay just yet — but hey, it’s a start. Want to dive in deeper? Read [indyjonas]’ thread on X.

Escaping US Tech Giants Leads European YouTuber To Open Source

May 17, 2025 by Tyler August 113 Comments

The video (embedded below) by [TechAltar] is titled “1 Month without US tech giants“, but it could have been titled “1 Month with Open Source Tools” — because, as it turns out, once you get out of the ecosystem set up by the US tech giants, you’re into the world of open source software (OSS) whether you want to be or not.

From a (German-made) Tuxedo laptop running their own Linux distro to a Fairphone with e/OS (which is French), an open version of Android, [TechAlter] is very keen to point out whenever Europeans are involved, which is how we learned that KDE has a physical headquarters, and that it’s in Berlin. Who knew?

He also gives his experiences with NextCloud (also German), can be used as an OSS alternative Google Workspaces that we’ve written about before, but then admits that he was the sole user on his instance. To which one must question: if you’re the sole user, why do you need a cloud-based collaborative environment? To try it out before getting collaborators involved, presumably.

Regardless what you think of the politics motivating this video, it’s great to see open source getting greater traction. While [TechAltar] was looking for European alternatives, part of the glory of open source is that it doesn’t matter where you’re from, you can still contribute. (Unless you’re Russian.) Have you found yourself using more open source software (or hardware) of late? Do you think the current political climate could lead to a broadening of its reach? Is this the year of the linux desktop? Let us know what you think in the comments. Continue reading “Escaping US Tech Giants Leads European YouTuber To Open Source” →

Turning A Chromebox Into A Proper Power-Efficient PC

May 14, 2025 by Maya Posch 21 Comments

Google’s ChromeOS and associated hardware get a lot of praise for being easy to manage and for providing affordable hardware for school and other educational settings. It’s also undeniable that their locked-down nature forms a major obstacle and provides limited reusability.

That is unless you don’t mind doing a bit of hacking. The Intel Core i3-8130U based Acer CXI3 Chromebox that the [Hardware Haven] YouTube channel got their mittens on is a perfect example.

The Acer CXI3 in all its 8th-gen Intel Core i3 glory. (Credit: Hardware Haven, YouTube)

This is a nice mini PC, with modular SODIMM RAM, an NVMe storage M.2 slot as well as a slot for the WiFi card (or SATA adapter). After resetting the Chromebox to its default configuration and wiping the previous user, it ran at just a few watts idle at the desktop. As this is just a standard x86_64 PC, the only thing holding it back from booting non-ChromeOS software is the BIOS, which is where [MrChromebox]‘s exceedingly useful replacement BIOSes for supported systems come into play, with easy to follow instructions.

Reflashing the Acer CXI3 unit was as easy as removing the write-protect screw from the mainboard, running the Firmware Utility Script from a VT2 terminal (Ctrl+Alt+F2 on boot and chronos as login) and flashing either the RW_LEGACY or UEFI ROM depending on what is supported and desired. This particular Chromebox got the full UEFI treatment, and after upgrading the NVMe SSD, Debian-based Proxmox installed without a hitch. Interestingly, idle power dropped from 2.6 watts under ChromeOS to 1.6 watts under Proxmox.

If you have a Chromebox that’s supported by [MrChromebox], it’s worth taking a poke at, with some solutions allowing you to even dualboot ChromeOS and another OS if that’s your thing.

Continue reading “Turning A Chromebox Into A Proper Power-Efficient PC” →