fidzu : debian

Ohai,

I have some pending, encrypted mails to answer. And some of my answers for the next few days (particularly to what pertains to the current in-discussion vote on LLM usage in Debian) will be unsigned, even though I'd like otherwise.

My desktop system at work is showing some data corruption, and I'm slowly backing up my data. Fortunately, it seems I haven't lost any data, but still, given I'm letting rsync run until it starts spewing I/O errors, then power down and let the machine cool a bit, and start again… it is a potentially long process.

And yes, this makes me somewhat angry. Why angry? Because I'm working on a brand-new computer (well, have used it for slightly over six months), custom-built to specs requested by my workplace. Specs that I don't really need, this machine is an utter luxury (i.e. an AMD Ryzen 9 9950X processor with 16 real cores / 32 threads; 128GB RAM in this day and age of RAM shortage, quite recent 32GB GPU, and lots of shiny lights seen in its huge fishbowl cabinet, liquid-based cooling…). The specs came not from me, but from people who had no idea what we would use them for. And yes, I expect the little fortune spent on this machine to be good for my use for probably a decade, as my previous computer was, but the amount paid was… exorbitant.

But still, what I learned recently is that the 4TB nVME SSD it has (a T-Force TM8FFJX34T) is… a very cheap brand, bought because it was close to half the price of other offerings similar in capacity. According to smartctl's output, th SSD operates with a Warning Comp. Temp. Threshold: 90 Celsius and Critical Comp. Temp. Threshold: 110 Celsius, which sounds sensible, even too high for my standards (my last two laptops have been fanless… yes, an ARM system is very different from a high-end gaming machine). I'm right now typing from my laptop, which shows 78°C and 82°C for warning/critical thresholds.

And as expected, under heavy sustained reads (backing up to my NFS server), the desktop's smartctl shows Temperature: 83 Celsius and, further down, Temperature Sensor 1: 107 Celsius and Temperature Sensor 2: 82 Celsius (don't know which of these would make the threshold jump). The SSD has sustained Media and Data Integrity Errors: 20 and Warning Comp. Temperature Time: 21 (although Critical Comp. Temperature Time: 0). At least one of my colleagues have shrugged and installed a SATA SSD, laying the huge nVME basically to waste.

Anyway… I also learned I am not the first, but the fourth person to notice this kind of issues in this system (out of ten similar purchased systems AIUI). It is completely unacceptable, and I'll be pushing our Institute's authorities to demand the provider to provide either good component quality for this very expensive system that has many luxury items, or to fix the system's build in a way the nVME does not heat as much as it currently does.

Anyway, sigh, I only wanted to say, please excuse me for not using my cryptographic keys for a couple of days 🙃

PS- I'm also currently not connected to IRC and Jabber (and some similar technologies), as my bouncer runs from my usual workstation.

13 Aug 2026 5:47pm GMT

Since I wrote about my fly30 ice skates, I'd continued to battle pain around the navicular bone in my feet. The action that seems to have finally fixed it was to perform a "punch out": a very localized remoulding of the area of the boot that presses against the sore area.

I basically followed the process from this helpful YouTube video.

I narrowed down the exact spot by borrowing some lipstick and transferring it from my navicular bone to the boot lining, then making that more permanent with a sharpie.

My punch was a spare part from a radiator valve which I packed with US cents (I couldn't fit any UK coins in). For the receiving-end, I tried another part from the radiator valve but I think it wasn't sufficiently larger than the punch to work well, so I swapped that out for a spoon.

I didn't have a temperature sensor I could use and I used a heat gun rather than a hairdryer, so I YOLO'd it a little. Some of the wrap on one of my boots is now distorted from where I didn't move the heat gun enough. It only took a minute or two to get the boot hot enough to be flexible. I set a 15 minute timer once the clamp was in place.

I've only skated one session since I did this but the pain seems to have gone! It's remarkably freeing to be skating without constantly trying to manage pain. Now I can focus on technique.

13 Aug 2026 8:28am GMT

Inspired by some recent reverse-engineering, here are some things I find wild by the original PlayStation GPU:

• VRAM is a flat 1024x512 16-bit image (555 + 1 bit alpha). You want more than just a framebuffer? Figure out yourself what goes where.
• Yes, that means you'll need to allocate two framebuffers and double-buffer everything yourself.
• Quads are common. No "triangles only" business here.
• Vertex coordinates are screen-space x/y integers. No floats or fixed-point. (I'm ignoring the GTE here, plus higher-level libraries.)
• Wait, where's z? There's no z. So there's no perspective correction. (This one is pretty famous)
• OK, so how do you give in subpixel coordinates? You don't. There's no AA after all.
• Texture coordinates (u/v) are uint8_t. There's no texture filtering either; everything is nearest-neighbor only.
• OK, so that means you can't have textures larger than 256x256 (pretty common in that era), but how do you give in the handle to the texture?
• You don't, it points directly to the 1024x512 VRAM. You manage yourself what goes where, remember?
• So can you an only have textures in the top-left 256x256? Hah, no, we give you a bit-packed "texture page" system that offsets all your u/v coordinates.
• Most textures are paletted to save VRAM (so instead of 555+1, your pixels now mean something like "two palette indexes"). Where does the palette live?
• Well, duh, that's a 256x1 (or 16x1, or whatever) area of VRAM too. The GPU does not care, you can use another texture's pixels as a palette if you feel like it.
• OK, so you said there's no z, how do you do z-buffering? You have a z-buffer, right… right?
• Yeah, sure, we're not cavemen. We have an "ordering table" that is your Z-buffer, drawn back-to-front. If you want 256 levels of Z, you just allocate an array of 256 linked-list pointers, and then you put your polygon into the one corresponding to the correct right Z.
• But, eh, what if my polygon is not completely flat in Z-space?
• Hello?
• Hello…?

12 Aug 2026 2:45pm GMT