[Alyssa Rosenzweig] has been tirelessly working on reverse engineering the GPU built into Apple’s M1 architecture as part of the Asahi Linux effort. If you’re not familiar, that’s the project adding support to the Linux kernel and userspace for the Apple M1 line of products. She has made great progress, and even got primitive rendering working with her own open source code, just over a year ago.
Trying to mature the driver, however, has hit a snag. For complex rendering, something in the GPU breaks, and the frame is simply missing chunks of content. Some clever testing discovered the exact failure trigger — too much total vertex data. Put simply, it’s “the number of vertices (geometry complexity) times amount of data per vertex (‘shading’ complexity).” That… almost sounds like a buffer filling up, but on the GPU itself. This isn’t a buffer that the driver directly interacts with, so all of this sleuthing has to be done blindly. The Apple driver doesn’t have corrupted renders like this, so what’s going on? Continue reading “Asahi GPU Hacking”→
These days, mass storage for computers is pretty simple. It either uses a rotating disk or else it is solid state. There are a few holdouts using tape, too, but compared to how much there used to be, tape is all but dead. But it wasn’t that long ago that there were many kinds of mass storage. Tapes, disks, drums, punched cards, paper tape, and even stranger things. Perhaps none were quite so strange though as the IBM 2321 Data Cell drive — something IBM internally called MARS.
What is a data cell you might ask? A data cell was a mass storage device from IBM in 1964 that could store about 400 megabytes using magnetic strips that looked something like about a foot of photographic film. The strips resided inside a drum that could rotate. When you needed a record, the drum would rotate the strip you needed to the working part and an automated process would remove the strip in question, wrap it around a read/write head and then put it back when it was done.
[Johnny] had a monitor that he was particularly fond of. The whole monitor appeared dead, and he decided to open it up and find out what could be wrong. He wound up fixing it — sort of — using a hairdryer. While we think his explanation of the problem is unlikely, we hate to armchair quarterback, and we applaud that he opened it up and got it working.
When something is dead, it is always a good idea to check the power and power supply, but that didn’t pan out in this case. In fact, the power supply board inside had what looked like reasonable voltage values throughout. The problem had to be something more subtle.
On October 23rd of 2001, the first Apple iPod was launched. It wasn’t the first Personal Media Player (PMP), but as with many things Apple the iPod would go on to provide the benchmark for what a PMP should do, as well as what they should look like. While few today remember the PMP trailblazers like Diamond’s Rio devices, it’s hard to find anyone who doesn’t know what an ‘iPod’ is.
Even as Microsoft, Sony and others tried to steal the PMP crown, the iPod remained the irrefutable market leader, all the while gaining more and more features such as video playback and a touch display. Yet despite this success, in 2017 Apple discontinued its audio-only iPods (Nano and Shuffle), and as of May 10th, 2022, the Apple iPod Touch was discontinued. This marks the end of Apple’s foray into the PMP market, and makes one wonder whether the PMP market of the late 90s is gone, or maybe just has transformed into something else.
After all, with everyone and their pet hamster having a smartphone nowadays, what need is there for a portable device that can ‘only’ play back audio and perhaps video?
Plenty of potential, but a cozy hacking space it is not
To us hackers and makers, the tools of our trade are often as important and interesting as the details of the hacks themselves, but what about the most important tool of all — the very space you use to make your magic happen? That may be your bedroom, a nearby hackerspace, and if you have the resources, you may even own a place of your own, and get to build your perfect workspace.
The latter situation is what [MichD] and partner [Brittany] found themselves in, having moved into their first place. Many couples focus on getting a hot tub in the garden or sorting the nursery, but these two are proper electronics nerds, so they converted a free-standing double wide garage into the nerdhub, learning as they went along, and documenting it in excruciating detail for your viewing pleasure.
Door fitted, framed up, and insulation in place. All ready for plasterboarding.
The building structurally is a single-skinned brick-built box, with a raw concrete floor. Pretty typical stuff for the UK (we’ve seen much worse), but not ideal for spending an extended amount of time in due to our damp, cold climate, at least in winter.
The first order of business was partitioning the front section for bike storage, and screeding the floor. Once the floor was solid, the walls and ceiling joists could be framed up, ready for fitting insulation material and covering with plasterboard.
Electrics were next in order, with the wires clipped to the brickwork, well away from where the plasterboard would be, therefore making it less likely to accidentally drill into a live cable when adding external fixtures.
Since the front part of the room was to be partitioned off, another access door was needed. This involved cutting out the bricks to fit a concrete lintel. With that installed, and the bricks above supported, the area below was cut out to the required shape. A somewhat nerve-wracking experience, if you ask us!
As any self-respecting hacker will tell you — no room build is complete without a decent amount of RGB bling, so the whole room was decked out with APA102 addressable LED strips. Control of these was courtesy of WLED running on an ESP32 module, with LedFX used on a nearby PC to perform music visualisation, just because.
Before the Ford marketing department started slapping Maverick badges on pickup trucks, the name had been attached to compact cars from the 70s instead. These were cheap even by Ford standards, and were built as a desperate attempt to keep up with Japanese imports that were typically higher quality and more efficient than most American cars at the time. Some people called them the poor man’s Mustang. While Ford and the other American car companies struggled to stay relevant during the gas crisis, it turns out that they could have simply slapped a lawn mower carburetor on their old Mavericks to dramatically improve fuel efficiency.
The old Maverick used a 5 L carbureted V8 engine, which is not exactly the pinnacle of efficiency even by 1970s standards. But [ThunderHead289] figured out that with some clever modifications to the carburetor, he could squeeze out some more efficiency. By using a much smaller carburetor, specifically one from a lawn mower, and 3D printing an adapter for it, he was able to increase the fuel efficiency to over 40 mpg (which is higher than even the modern Mavericks) while still achieving a top speed of 75 mph.
While it’s not the fastest car on the block with this modification, it’s still drives well enough to get around. One thing to watch out for if you try this on your own classic car is that some engines use fuel as a sort of coolant for certain engine parts, which can result in certain problems like burned valves. And, if you don’t have a lawnmower around from which to borrow a carb, take a look at this build which 3D prints one from scratch instead.
Conceptually, FDM 3D printing is quite a simple process: you define a set of volumes in 3D space, then the slicing software takes a cut through the model at ever-increasing heights, works out where the inner and outer walls are, and then fills in the inside volume sparsely in order to tie the walls together and support the top layers that are added at the end.
But as you will find quite quickly, when models get larger and more complex, printing times can quickly explode. One trick for large models with simple shapes but very low structural needs is to use so-called ‘vase mode’, which traces the outline of the object in a thin, vertical spiral. But this is a weak construction scheme and allows only limited modelling complexity. With that in mind, here’s [Ben Eadie] with a kind-of halfway house technique (video, embedded below) that some might find useful for saving on printing time and material.
This solid shape is mostly cut-through to make supporting ribs between the walls of the shell
The idea is to use vase mode printing, but by manipulating the shell of the model, adding partially cut-through slots around the perimeter, and critically, adding one slot that goes all the way.
First you need a model that has an inner shell that follows the approximate shape of the outer, which you could produce by hollowing out a solid, leaving a little thickness. By making the slot width equal to half the thickness of the nozzle size and stopping the slots the same distance from the outer shell, vase mode can be used to trace the outline of shape, complete with supporting ribs in between the inner and outer walls of the shell.
Because the slot is narrower than the extrudate, the slot walls will merge together into one solid rib, tying the objects’ walls to each other, but critically, still allowing it to be printed in a continuous spiral without any traditional infill. It’s an interesting idea, that could have some merit.
