Linux And C In The Browser

May 28, 2022 by Al Williams 45 Comments

There was a time when trying to learn to write low-level driver or kernel code was hard. You really needed two machines: one to work with, and one to screw up over and over again until you got it right. These days you can just spin up a virtual machine and roll it back every time you totally screw up. Much easier! We don’t think it is all that practical, but [nsommer] has an interesting post about loading up a C compiler and compiling Linux for a virtual machine. What’s different? Oh, the virtual machine is in your browser.

The v86 CPU emulator runs in the browser and looks like a Pentium III computer with the usual hardware. You might think it is slow and it certainly isn’t going to be fast as a rocket, but it does translate machine code into WebAssembly, so performance isn’t as bad as you might think.

The post goes into detail about how to build and create a simple machine web page that hosts v86. Once you cross-compile the kernel you can boot the machine up virtually. The other interesting part is the addition of tcc which is a pretty capable C compiler and much smaller and faster than the very traditional gcc.

The tcc build is tricky because the normal build process compiles the compiler and then uses the same compiler to build the default libraries. When cross-compiling, this doesn’t work well because the library you want for the host compile is different from the library you want to target for the second pass. You’ll see how to work around that in the post. The post continues to show how to do remote debugging and even gets QEMU into the mix. Debugging inside v86 doesn’t seem to work so far. There are more posts on this topic promised.

Honestly, this is one of those things like teaching a chicken to play checkers. It can be done, there’s little practical value, but it is still something to see. On the other hand, if you spend the weekend working through this, your next Linux porting project ought to seem easy by comparison.

Amazing what you can pull off with WebAssembly. If you need a quick introduction, check this one out from [Ben James].

Flashing TI Chips With An ESP

April 3, 2022 by Bryan Cockfield 29 Comments

Texas Instruments is best known to the general public for building obsolete calculators and selling them at extraordinary prices to students, but they also build some interesting (and reasonably-priced) microcontrollers as well. While not as ubiquitous as Atmel and the Arduino platform, they can still be found in plenty of consumer electronics and reprogrammed, and [Aaron] aka [atc1441] demonstrates how to modify them with an ESP32 as an intermediary.

Specifically, the TI chips in this build revolve around the 8051-core microcontrollers, which [Aaron] has found in small e-paper price tags and other RF hardware. He’s using an ESP32 to reprogram the TI chips, and leveraging a web server on the ESP in order to be able to re-flash them over WiFi. Some of the e-paper displays have built-in header pins which makes connecting them to the ESP fairly easy, and once that’s out of the way [Aaron] also provides an entire software library for interacting with these microcontrollers through the browser interface.

Right now the project supports the CC2430, CC2510 and CC1110 variants, but [Aaron] plans to add support for more in the future. It’s a fairly comprehensive build, and much better than buying the proprietary TI programmer, so if you have some of these e-paper displays laying around the barrier to entry has been dramatically lowered. If you don’t have this specific type of display laying around, we’ve seen similar teardowns and repurposing of other e-paper devices in the past as well.

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The Noble Effort To Put OpenSCAD In The Browser

March 14, 2022 by Jenny List 58 Comments

In a world of CAD packages with arcane or unfriendly interfaces there’s a stand-out player that’s remarkable because it has no interface. OpenSCAD is a CAD package for coders, in which all design elements are created in a scripting language rather than graphically. It’s maybe not for everyone but it has a significant following, and its reach has been extended further as you can now run it from within a modern web browser.

The origins of this project can be tracked back to August of 2021, when when Autodrop3D’s [mmiscool] offered a sizable bounty for anyone willing to port the parametric CAD modeler to web assembly. Developer [Dominick Schroer] ultimately answered the call with openscad-wasm, which implements the core of OpenSCAD as a JavaScript ES6 module. From there, it just needed to get paired with a user interface, and off to the cloud we go.

Opening it up and giving it a go, we found it to be a very usable OpenSCAD version, albeit a little slower to render than the desktop equivalent on a mediocre laptop. We didn’t try exporting and printing an STL, but so far it has given us no reason to believe it wouldn’t be every bit as useful as the version you’re used to.

But wait, there’s more! Parallel to this effort, [Olivier Chafik] has also been working on his own idea of what OpenSCAD in the web should be. He’s using the same core developed by [Dominick], but has combined it with the Monaco editor from Microsoft and a Javascript STL viewer. Despite being very similar, we’re happy to report there’s no rivalry here; in fact, according to the video after the break, it sounds like two the projects have already swapped a bit of code.

The move among desktop applications to move into the browser and often into a pay-to-play cloud has seemed relentless over recent years, so it’s pleasing to see a rare example of a browser migration that’s open-source. It has the handy effect of bringing the CAD package to platforms such as tablets or Chromebooks which wouldn’t normally be an OpenSCAD platform, and this we like, a lot.

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Cloud-Based Atari Gaming

July 29, 2021 by Bryan Cockfield 4 Comments

While the Google Stadia may be the latest and greatest in the realm of cloud gaming, there are plenty of other ways to experience this new style of gameplay, especially if you’re willing to go a little retro. This project, for example, takes the Atari 2600 into the cloud for a nearly-complete gaming experience that is fully hosted in a server, including the video rendering.

[Michael Kohn] created this project mostly as a way to get more familiar with Kubernetes, a piece of open-source software which helps automate and deploy container-based applications. The setup runs on two Raspberry Pi 4s which can be accessed by pointing a browser at the correct IP address on his network, or by connecting to them via VNC. From there, the emulator runs a specific game called Space Revenge, chosen for its memory requirements and its lack of encumbrance of copyrights. There are some limitations in that the emulator he’s using doesn’t implement all of the Atari controls, and that the sound isn’t available through the remote desktop setup, but it’s impressive nonetheless

[Michael] also glosses over this part, but the Atari emulator was written by him “as quickly as possible” so he could focus on the Kubernetes setup. This is impressive in its own right, and of course he goes beyond this to show exactly how to set up the cloud-based system on his GitHub page as well. He also thinks there’s potential for a system like this to run an NES setup as well. If you’re looking for something a little more modern, though, it is possible to set up a cloud-based gaming system with a Nintendo Switch as well.

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Browser Makes Tiny Office Suite

October 13, 2020 by Al Williams 17 Comments

There’s a recent craze of people living in tiny houses of 400 square feet down to as little as 80 square feet. Maybe [zserge] was thinking about that and created a very tiny office suite in which each tool weighs in at less than 1K. If you are guessing you couldn’t squeeze much functionality in C or C++ code or even assembly, you’d be right. The language of choice? HTML and JavaScript. So while the code is small, it relies on a pretty big piece of software. On the other hand, you have a browser open right now, so the incremental cost of using these tools is very small.

We get the idea that there’s not much chance this is going to sweep the shelves of Microsoft Office, Libre Office, and all the many competitors. However, it is a pretty stunning example of what you can do with modern HTML. There’s even a GitHub repo and a subreddit.

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Maxing Out Browser Tabs With 2TB Of Memory

March 30, 2020 by Lewin Day 39 Comments

Tabbed browsing was a gamechanger, allowing users to effectively browse multiple websites at once without losing context. It proved a better solution than using multiple windows, and was an efficiency boon celebrated by all. Many of us are tab fiends, opening great numbers at a time as a habitual part of our workflow. [Linus] decided to find out just how many he could open on a system armed with a full 2TB of RAM.

As may be obvious, setting up a system with 2TB of RAM is no mean feat. Special server-grade RAM modules were sourced, packing 128GB of RAM each, set up for ECC operation. Packing out 16 slots, there’s a performance penalty to addressing so much RAM with a single CPU, but for memory-intensive work, it’s worthwhile. The CPU in question is an AMD 64-core processor, providing plenty of grunt for the task at hand.

In testing, the machine began to slow down long before the RAM was full. Beyond 5000 tabs, things began to crawl. At 6000 tabs, it was simply impractical to open more, with the machine taking a full 26 seconds to respond to a single click. Memory usage at this point was just 200GB, suggesting that software limitations were getting in the way of opening yet more tabs.

While it’s not a useful measure of anything important, it’s fun to explore the limits nonetheless. We’ve seen their projects before, such as this original Xbox casemod. Video after the break.

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The Smart Home Gains An Extra Dimension

December 29, 2019 by Ben James 15 Comments

With an ever-growing range of smart-home products available, all with their own hubs, protocols, and APIs, we see a lot of DIY projects (and commercial offerings too) which aim to provide a “single universal interface” to different devices and services. Usually, these projects allow you to control your home using a list of devices, or sometimes a 2D floor plan. [Wassim]’s project aims to take the first steps in providing a 3D interface, by creating an interactive smart-home controller in the browser.

Note: this isn’t just a rendered image of a 3D scene which is static; this is an interactive 3D model which can be orbited and inspected, showing information on lights, heaters, and windows. The project is well documented, and the code can be found on GitHub. The tech works by taking 3D models and animations made in Blender, exporting them using the .glTF format, then visualising them in the browser using three.js. This can then talk to Hue bulbs, power meters, or whatever other devices are required. The technical notes on this project may well be useful for others wanting to use the Blender to three.js/browser workflow, and include a number of interesting demos of isolated small key concepts for the project.

We notice that all the meshes created in Blender are very low-poly; is it possible to easily add subdivision surface modifiers or is it the vertex count deliberately kept low for performance reasons?

This isn’t our first unique home automation interface, we’ve previously written about shAIdes, a pair of AI-enabled glasses that allow you to control your devices just by looking at them. And if you want to roll your own home automation setup, we have plenty of resources. The Hack My House series contains valuable information on using Raspberry Pis in this context, we’ve got information on picking the right sensors, and even enlisting old routers for the cause.