What to do if you have a really cool old HP MicroServer that just can’t keep up with the demands of today? [jacksonliam] decided to restomod it by installing a mini PC into the drive bay.
The HP N54L MicroServer was still running, but its soldered CPU and non-standard motherboard made a simple upgrade impossible. Evaluating the different options, [jacksonliam] decided to save the case and PSU by transplanting an Intel Alder Lake mini PC into the drive bay with 3D printed brackets and heat set inserts.
Selecting a fanless “router” model to increase reliability, he was able to find an M.2 to mini-SAS adapter to attach the four drive cage to the NVME slot on the new PC. Power is supplied via the 12 V line on the ATX power supply and one of the mini PC’s Ethernet lines was broken out to a 3D printed PCI slot cover.
Like playing around with Linux on low-power devices? You’d be hard pressed to find a better example than the [tvlad1234]’s linux-ch32v003 project. It’s not just a one-off — it’s something you could build right now, since it requires hardly any extra parts.
With help of a 8 MB PSRAM chip for RAM supplementation purposes and an SD card, plus some careful tailoring of the Linux .config parameters, you get Linux on a chip never meant to even come close to handling this much power. The five minutes it takes to boot up to a prompt is part of the experience.
As usual with [tvlad1234]’s projects, there’s a fun twist to it! Running Linux on this chip is only possible thanks to [chlohr]’s mini-rv32ima project, which, as you might remember, is a RISC-V emulator. Yes, this runs Linux by running a RISC-V emulator on a RISC-V chip. The main reason for that is because the MCU can’t map the PSRAM chip into RAM, but if you use an emulator, memory mapping is only a matter of software. Having applied a fair amount of elbow grease, [tvlad1234] brings us buildroot and mainline Linux kernel configs you can compile to play with this — as well as a single-layer-ready KiCad board project on GitHub. Yep, you could literally etch a PCB for this project from single-sided copper-clad FR4 with a bit of FeCl3.
While the CH32V003 is undoubtedly a more impressive target for Linux, the RP2040 Linux project might be more approachable in terms of having most of the parts in your parts box. At least, up until we start valuing the CH32V003 for all the cool stuff it can do!
In the 1967 movie The Graduate, a wise older man gives some advice to the title character: plastics. Indeed, plastics would become big business. In 1962, though, a computer-savvy character might have offered a different word: transfluxor. What’s a transfluxor? Well, according to computer history sleuth [Ken Shirriff], it was the heart of a 20-pound transistor computer from Arma. Of course, plastics turned out to be a better bet, but in 1962, the transfluxor seemed to be the wave of the future.
In 1962, most computers were room-sized, but the Arma was “micro” taking up just 0.4 cubic feet — less than an Apple II. It would eventually spawn computers used in ships at sea and airplanes ranging from the Concorde to Air Force One.
We’ve seen quite a few DIY 2G networks over the years, but the 4G field has been relatively barren. Turns out, there’s an open source suite called srsRAN that lets you use an SDR for setting up an LTE network, and recently, we’ve found a blog post from [MaFrance351] (Google Translate) that teaches you everything you could need to know if you ever wanted to launch a LTE network for your personal research purposes.
For a start, you want a reasonably powerful computer, a transmit-capable full-duplex software defined radio (SDR), suitable antennas, some programmable SIM cards, and a few other bits and pieces like SIM card programmers and LTE-capable smartphones for testing purposes. Get your hardware ready and strap in, as [MaFrance351] guides you through setting up your own base station, with extreme amounts of detail outlining anything you could get caught up on.
For a while around a quarter century ago PC motherboards came with a special slot, a little shorter than the PCI slots which ruled the roost back then, and offset from them further into the case. This was the Accelerated Graphics Port, or AGP, a standard created to more quickly serve the 3D graphics cards which were then taking the world by storm. It was everywhere for a few years, then in the mid-2000s it was replaced by PCI Express and faded into obscurity. [Peter] has a Socket 7-based NAS with an AGP slot, and was left wondering whether the unused port could be put to a worthwhile purpose.
AGP is a superset of PCI clocked at 66 MHz, and usually benefiting from having its own exclusive bridge to the processor bus. Thus he reasoned that he could make an AGP to PCI adapter and it might work, as the right connections are all there. A hacked-together version was made by butchering two riser cards, and when a network card worked quite happily he knew he was on to something and made a PCB. There’s a caveat that it only works with 66-MHz capable PCI cards so not everything will work, but if you’re one of the very few people who must be in the market for one, he can do you a PCB.
Concluding a four-part repair-a-thon on a stack of Cybiko handheld computers, [Robert] over at Robert’s Retrocovered the intricate details of fixing a last batch of four in a nearly one-hour long video. These devices, with their colorful transparent cases, are a great time capsule of the early 2000s. Even with their limited hardware, they provided PDA-like capabilities to teens years before smartphones were a thing, with features including music playback and wireless chat (albeit limited to recipients within 100 meters).
Of the four units covered in this video, they are all the original Cybiko Classic, with two each of the first and second revision, none of which were booting due to a bad Flash chip. Another issue was the dead rumble motors on them, which fortunately are the easiest to replace. One of the units also has a dead display, which did not get replaced this time around.
Insides of a Cybiko Classic (Credit: Robert’s Retro, YouTube)
The flash chip replacement was a bit more of a headache, as these devices don’t just take any chip, mostly due to how much the system relies on the ready-busy line. This led [Robert] to replace the old 4 Mb AT45DB041 chips with the 16 Mb Atmel AT45DB161. Previously he had taken 1 MB chips from an expansion cartridge to replace more dead flash chips, so those were replaced with 2 MB chips.
With fresh flash in place, the next challenge was to get these written with a firmware image, with the v2 Cybiko units already having CyOS on the separate 256 kB Flash chip, but the v1 units relying on the single big Flash chip for all storage. Fortunately, an enterprising member of the community developed a tool to ease this ordeal by allowing a Cybiko unit in its serial dock to be flashed with no issues, other than the 2 MB Flash causing some issues as this was a previously unknown hardware configuration.
[Robert] now has four working Cybiko units, with one being headless due to the busted screen, and more room for apps on the 2 MB units than a 2000s teenager would have known what to do with.
Hacks are rough around the edges by their nature, so we love it when we get updates from makers about how they’ve improved their process. [Denny] from Shake the Future has just provided an update on his microwave casting process.
Sticking metal in a microwave certainly seems like it would be a bad idea at first, but with the right equipment it can work quite nicely to develop a compact foundry. [Denny] walks us through the process start to finish in this video, including how to build the kilns, what materials to use, and how he made several different investment castings using the process. The video might be worth watching just for all the 3D printed tools he’s built to aid in the process — it’s a great example of useful 3D prints to accompany your fleet of little plastic boats.
A lot of the magic happens with a one minute on and six minutes off cycle set by a simple plug timer. This allows a more gradual ramp to burn out the PLA or resin than running the microwave at full blast which can cause some issues with the kiln, although nothing catastrophic as demonstrated. Vacuum is applied to the mold with a silicone sleeve cut from a swimming cap while pouring the molten metal into the mold to draw the metal into the cavities and reduce imperfections.
We appreciate the shout out to respirators while casting or cutting the ceramic fiber mat. Given boric acid’s effects, [PDF] you might want to use safety equipment when handling it as well or just use water as that seems like a valid option.
