The SGI O2 was SGI’s last-ditch attempt at a low-end MIPS-based workstation back in 1996, and correspondingly didn’t use the hottest parts of the time, nor did it offer much of an upgrade path. None of which is a concern to hobbyists who are more than happy to work around any hardware- and software limitations to e.g. install much faster CPUs. While quite a few CPU upgrades were possible with just some BGA chip reworking skills, installing the 900 MHz RM7900 would require some PROM hacking, which [mattst88] recently took a shake at.

The initial work on upgrading SGI O2 systems was done in the early 2000s, with [Joe Page] and [Ian Mapleson] running into the issue that these higher frequency MIPS CPUs required a custom IP32 PROM image, for which they figured that they’d need either SGI’s help or do some tricky reverse-engineering. Since SGI is no longer around, [mattst88] decided to take up the torch.

After downloading a 512 kB binary dump of the last version of the O2’s PROM, he set to work reverse-engineering it, starting by dissembling the file. A big part of understanding MIPS PROM code is understanding how the MIPS architecture works, including its boot process, so much of what followed was a crash-course on the subject.

With that knowledge it was much easier to properly direct the Capstone disassembler and begin the arduous process of making sense of the blob of data and code. The resulting source files now reassemble into bit-identical ROM files, which makes it likely that modifying it to support different CPUs is now possible with just a bit more work.

For those who want to play along, [mattst88] has made his ip32prom-decompiler project available on GitHub.

Thanks to [adistuder] for the tip.

Top image: Silicon Graphics 1600SW LCD display and O2 workstation. (Source: Wikimedia)

Phased-array radars are great for all sorts of things, whether you’re doing advanced radio research or piloting a fifth-generation combat aircraft. They’re also typically very expensive. [Nawfal] hopes to make the technology more affordable with an open-source radar design of their own.

The design is called the AERIS-10, and is available in two versions. Operating at 10.5 GHz, it can be built to operate at ranges between 3 or 20 kilometers depending on the desired spec. The former uses an 8 x 16 patch antenna array, while the latter extends this to a 32 x 16 array. Either way, each design is capable of fully-electronic beam steering in azimuth and can be hacked to enable elevation too—one of the most attractive features of phased array radars. The hardware is based around an STM32 microcontroller, an FPGA, and a bunch of specialist clock generators, frequency synthesizers, phase shifters, and ADCs to do all the heavy lifting involved in radar.

Radar is something you probably don’t spend a lot of time thinking about unless you’re involved in maritime, air defence, or weather fields. All of which seem to be very much in the news lately! Still, we feature a good few projects on the topic around these parts. If you’ve got your own radar hacks brewing up in the lab, don’t hesitate to let us know. 

If a zipper breaks, a 3D printer might not be the first tool one reaches for — but it’s more feasible than one might think. [MisterJ]’s zipper slider replacement is the kind of 3D print that used to be the domain of well-tuned printers only, but most hobbyist printers should be able to handle it nowadays.

What really sets this design apart from other printed versions is its split construction. Putting a new slider onto a zipper usually requires one to free the ends of the zipper by unsewing them. [MisterJ]’s two-part design instead allows the slider to be assembled directly onto the zipper, without the hassle of unsewing and re-sewing anything. That’s a pretty significant improvement in accessibility.

Want to make some adjustments? Good news, because the files are in STEP format which any CAD program will readily understand. We remember when PrusaSlicer first gained native STEP support and we’re delighted that it’s now a common feature in 3D printer software.

[MisterJ]’s zipper slider design is available in a variety of common sizes, in both standard (zipper teeth face outward) and reverse (zipper teeth face inward) configurations. Naturally a metal slider is more durable than a plastic one, but being able to replace broken parts of a zipper with a 3D printer is a pretty handy thing. Speaking of which, you can also 3D print a zipper box replacement should the squarish bit on the bottom get somehow wrecked or lost.

Odds are, you’ve taken pills before; it’s a statistical certainty that some of you reading this took several this morning. Whenever you do, you’re at the mercy of the manufacturer: you’re trusting that they’ve put in the specific active ingredients in the dosage listed on the package. Alas, given the world we live in, that doesn’t always happen. Double-checking actual concentrations requires expensive lab equipment like gas chromatography. It turns out checking for counterfeit pills is easier than you’d think, thanks to a technique called Disintegration Fingerprinting.

It’s delightfully simple: all you need is a clear plastic cup, a stir plate, and a handful of electronic components — namely, a microcontroller, a servo, and an IR line-following sensor. You’ve probably played with just such a sensor: the cheap ones that are a matched pair of LED and photodetector. It works like this: the plastic cup, filled with water, sits upon the stir plate. To start the device, you turn on the stir plate and actuate the servo to drop the pill in the water. The microcontroller then begins recording the signal from the photo-diode. As the pill breaks up and/or dissolves in the water, the swirling bits are going to reflect light from the IR LED. That reflectance signal over time is the Disintegration Fingerprint (DF), and it’s surprisingly effective at catching fakes according to the authors of the paper linked above. Out of 32 different drug products, the technique worked on 90% of them, and was even able to distinguish between generic and brand-name versions of the same drug.

Of course, you do need a known-good sample to generate a trustworthy fingerprint, and there’s that pesky 10% of products the technique doesn’t work on, but this seems like a great way to add some last-mile QA/QC to the drug distribution chain, particularly in low and middle-income countries where counterfeit drugs are a big problem.

We’ve featured pill-identifiers before, but machine vision is going to be much more easily fooled by counterfeits than this method. If your problem isn’t worrying that your pills are fake, but forgetting to take them, we’ve had projects to help with that, too.

Thanks to [Zorch] for the tip!

Here's a nifty bit of design from Brent Biglow, who runs Canadian outfit Biglow Woodworks. The Book Stop is a wall-mounted bookshelf with an integrated, adjustable bookend. But it doesn't rest on the shelf; instead it hangs from the ceiling of the structure, riding in a dovetailed groove.

The unit itself arrives flatpack, and the user can easily assemble it with no tools—there's no hardware. The sides attach to the horizontals via, again, sliding dovetails.

The $180 units are available in Cherry or Walnut and will ship this summer.

If you live in a house with an attic, basement or garage, purchasing a drinks cooler is no big deal. But if you live in a space-tight apartment, acquiring such a bulky object warrants careful consideration. Where will it live, during the hundreds of days a year you're not barbecuing or picnicking?

Coleman has addressed this issue with their new Snap 'N Go cooler. The hard-sided object borrows a trick from folding storage crates, collapsing down to just 1/3rd of its original volume.

Watertightness is conferred by a removable interior bladder, which collapses flat.

The cooler can be collapsed in seconds, and the bladder fitted neatly within the lid.

"Assembly" is similarly easy.

The company sells them in three sizes: A $200 35-quart model, a $220 45-quart model and a $240 55-quart model. Dimensions and specs are below.