The venerable Intel 486 was released in 1989 as the successor to the extremely popular Intel 386. It was the minimum recommended processor for Windows 98.  (Surprisingly, the Windows 95 minimum was a 386!)  But by the time XP rolled around, you needed at least a 233 MHz Pentium to install. Or at least that was the case until recently when an extremely dedicated user on MSFN named [Dietmar] showed how he hacked the XP kernel so it could run on the classic chip!

The biggest issue preventing XP from working on earlier processors is an instruction introduced on the Pentium: CMPXCHG8B. This instruction compares two 8-byte values and takes different actions depending on an equality test. It either copies the 8 bytes to a destination address or loads it into a 64-bit register. Essentially, it does what it says on the tin: it CoMPares and eXCHanGes some values. If you want to dig into the nitty-gritty details, you can check out this info on the instruction taken from the x86 datasheet.

Without getting too technical, know that this instruction is vital for performance when working with large data structures. This is because one instruction moves 8 bytes at a time, unlike the older CMPXCHG instruction, which only moves a single byte. Essentially, [Dietmar] had to find every usage of CMPXCHG8B and replace it with an equivalent series of CMPXCHG instructions.

On a side note, the once well-known and devastating Pentium F00F bug was caused by a faulty encoding of the CMPXCHG8B instruction. This allowed any user, even unprivileged users, to completely lock up a system, requiring a full reset cycle!

So [Dietmar] was successful, and now you can run the German version of Windows XP on either a real 486 or an emulated one. The installer is available on the Internet Archive and there’s a detailed video below demonstrating installing it on the 86Box virtual machine host.

Thanks to [DosFox] for the tip!

So you say you missed the Great Solar Storm of 2024 along with its attendant aurora? We feel you on that; the light pollution here was too much for decent viewing, and it had been too long a day to make a drive into the deep dark of the countryside survivable. But fear not — the sunspot that raised all the ruckus back at the beginning of May has survived the trip across the far side of the sun and will reappear in early June, mostly intact and ready for business. At least sunspot AR3664 seems like it’s still a force to be reckoned with, having cooked off an X-class flare last Tuesday just as it was coming around from the other side of the Sun. Whether 3664 will be able to stir up another G5 geomagnetic storm remains to be seen, but since it fired off an X-12 flare while it was around the backside, you never know. Your best bet to stay informed in these trying times is the indispensable Dr. Tamitha Skov.

Back here on our soon-to-be-incinerated planet, you know we’ve reached the peak of the AI hype curve when you see something like AI competitive thermal paste being hawked. That’s the marketing niche Cooler Master has staked out for its new Cyrofuze 5 thermal paste, which is supposed to somehow make your computer smarter by keeping it cooler? Or maybe not; it’s not really clear from Cooler Master’s Chinese website for the product what the AI advantages are, and sadly the Cryofuze 5 line doesn’t seem to be offered on the US site. Which is a shame, because the new smartening goo comes in six designer colors that for all the world look like a Bob Ross palette — it that alizarin crimson and phthalo blue? Who in their right mind wouldn’t want a chance to color coordinate their thermal grease while simultaneously making their machine more AI competitive?

Speaking of AI, we’ve covered a lot of interactions between humans and autonomous vehicles in this column, with most of them tending toward the violent. But we’ve finally got a more heartwarming interaction to report, where a pedestrian helped a stuck delivery vehicle out of a tough spot. The truck, which is really only a little bigger than those munchie-delivering robots that ply college campuses, maneuvered itself onto a driveway sporting a pair of speed bumps spaced almost exactly as far apart as the vehicle’s wheelbase. The front wheels made it over the first bump, but when it came time to climb both obstacles at the same time, the poor little truck just couldn’t manage it. The fact that the bumps were a significant fraction of the wheel diameter on the tiny truck likely didn’t help, but thankfully a pedestrian took pity and gave the little fella a push. The bot’s rear wheels seemed to be having trouble clearing the last bump, too; the video cuts off too soon to tell, but we’ll give it the benefit of the doubt.

Victim blame is generally in bad form, but if you don’t even bother to change the default password, can you really call a cyberattack a “break-in”? That’s the question we have after learning of an alarming increase in cyberattacks against public infrastructure in the US, including public water supplies in Pennsylvania and Texas. While the separate attacks resulted in no damage to the physical plants, the article links to a report listing some attacks that did result in damage, including an intentional release of 800,000 liters of sewage in Australia in 2000.

And finally, speaking of cybersecurity, if you’ve ever procrastinated on keeping your OS patched, what happened when a Windows XP machine was put online with no protection should spur you into action. YouTuber Eric Parker put an XP machine on the raw internet — no router, no firewall, and no anti-malware software. It only took about ten minutes for the first signs of infection to appear, and things went downhill pretty fast from there. Parker notes that the same setup on a Windows 7 machine resulted in no major malware infections after several hours, which should be a gut punch to those who fought so long against updating from XP.