While discussing the design, [Francis] reveals his first pass at the instruction set, discussed what he found wrong about it, and then reveals the final set composed of real instructions and some macros to handle other common cases.
Continue reading “Virtual CPU Stays on Script”
[Alexander Reben] makes tech art, and now he’s encouraging you to do the same — within a URL. The gimmick? Making the code small enough to fit the data portion of a link. And to help with that, he has set up a webpage that uncompresses and wraps code from the URL and inserts it into the HTML on the fly. His site essentially applies or un-applies all the tricks of JS minification in the URL, and turns that into content.
So, for instance,
Something strikes us as fishy about passing JS code opaquely in links, but since the URL decodes on [Alexander]’s server, we don’t see the XSS attack just yet. If you can find the security problem with this setup, or better yet if you write up a nice animation, let us know in the comments.
People have been interested in chess-playing computers before there were any chess-playing computers. In a 1950 paper, [Claude Shannon] defined two major chess-playing strategies. Apparently, practical chess programs still use the techniques he outlined. If you’ve ever wondered how to make a computer play chess [FreeCodeCamp] has an interesting post that walks you through building a chess engine step-by-step.
Continue reading “Chess AI, Old School”
Most old-school remote controlled cars broadcast their controls on 27 MHz. Some software-defined radio (SDR) units will go that low. The rest, as we hardware folks like to say, is a simple matter of coding.
So kudos to [watson] for actually doing the coding. His monster drift project starts with the basics — sine and cosine waves of the right frequency — and combines them in just the right durations to spit out to an SDR, in this case a HackRF. Watch the smile on his face as he hits the enter key and the car pulls off an epic office-table 180 (video embedded below).
Continue reading “SDR and Node.js Remote-Controlled Monster Drift”
Forth has a strong following among embedded developers. There are a couple of reasons for that. Almost any computer can run Forth, even very small CPUs that would be a poor candidate for running programs written in C, much less host a full-blown development environment. At its core, Forth is very simple. Parse a word, look the word up in a dictionary. The dictionary either points to some machine language code or some more Forth words. Arguments and other things are generally carried on a stack. A lot of higher-level Forth constructs can be expressed in Forth, so if your Forth system reaches a certain level of maturity, it can suddenly become very powerful if you have enough memory to absorb those definitions.
If you want to experiment with Forth, you probably want to start learning it on a PC. There are several you can install, including gForth (the GNU offering). But sometimes that’s a barrier to have to install some complex software just to kick the tires on a system.
Continue reading “Browsing Forth”
Until recently, computer-aided design (CAD) software was really only used by engineering companies who could afford to pay thousands of dollars a year per license. The available software, while very powerful, had a very high learning curve and took a lot of training and experience to master. But, with the rise of hobbyist 3D printing, a number of much more simple CAD programs became available.
While these programs certainly helped makers get into 3D modeling, most had serious limitations. Only a few have been truly open-source, and even fewer have been both open-source and parametric. Parametric CAD allows you to create 3D models based on a series of parameters, such as defining a cube by its origin and dimensions. This is in contrast to sculpting style 3D modeling software, which is controlled much more visually. The benefit of parametric modeling is that parameters can be changed later, and the model can be updated on the fly. Features can also be defined mathematically, so that they change in relation to each other.
Continue reading “Open-Source Parametric CAD in Your Browser”
LED matrix projects are all over the place, but this one is interesting for its simplicity: it’s an LED matrix that is driven straight from an ESP8266 board. [Ray] put it together as a quick project for his students to teach the basics of LED programming.
Just get on the same network and load up the module’s WiFi address for a graphical representation of the 5×7 LED matrix. Pick a color, turn pixels on or off, or choose a predefined pattern and send it to the hardware. This is a powerful way to get use input and with this as a guide it’s fast to set up for pretty much an application you can think of. Just work your way through the documents he put together for the workshop (Zip file link), including all of the code and the slides he used to run the workshop.
Continue reading “Web Matrix Control Proves Power of ESP8266”