Talking To A Texas Instruments Calculator

Texas Instruments is a world-class semiconductors company, but unfortunately what they are best known for among the general public is dated consumer-grade calculators thanks to entrenched standardized testing. These testing standards are so entrenched, in fact, that TI has not had to update the hardware in these calculators since the early 90s. They still run their code on a Z80 microcontroller, but [Ben Heck] found himself in possession of one which has a modern ARM coprocessor in it and thus can run Python.

While he’s not sure exactly what implementation of Python the calculator is running, he did tear it apart to try and figure out as much as he could about what this machine is doing. The immediately noticeable difference is the ARM coprocessor that is not present in other graphing calculators. After some investigation of test points, [Ben] found that the Z80 and ARM chips are communicating with each other over twin serial lines using a very “janky” interface. Jankiness aside, eventually [Ben] was able to wire up a port to the side of the calculator which lets him use his computer to send Python commands to the device when it is in its Python programming mode.

While there are probably limited use cases for 1980s calculators to run Python programs, we can at least commend TI for attempting to modernize within its self-built standardized testing prison. Perhaps this is the starting point for someone else to figure out something more useful to put these machines to work with beyond the classroom too. We’ve already seen some TI-84s that have been modified to connect to the Internet, for example.

Thanks to [Nikša] for the tip!

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Change Desktop Environments On… IOS?

While Apple’s modern operating systems may seem like they exist independently of the rest of the computing world, they are actually close cousins of modern versions of Linux. The primary link between the two is that Apple’s offerings are Unix-based and even though Linux isn’t Unix in the strict sense, it’s built to be extremely Unix-like. Plenty of Linux software is POSIX-compliant, meaning it is effectively compatible with true Unix. But what can we do with that information? Well, to start, we can run Linux desktop environments on top of an iOS install on your favorite iPhone or iPad.

To be sure, we will be filing this hack in the “because you can” category. [Torrekie], the creator of this project, has plenty of builds (Google translate from Chinese) where the boundaries between things like Linux and Unix are either blurred or nonexistant. In this particular project, a jailbroken iOS device is essentially gifted a ported version of XFCE which is able to run fairly well on iOS thanks to its compatibility with Unix environments. Details on how this was accomplished are sparse without a full investigation of the source code right now, but you can head over to the repository if you are curious enough to try this for yourself. [Torrekie] does note that this will only work with iOS devices that have been jailbroken using the “unc0ver” jailbreak only though.

To be sure, the relationship between modern Apple operating systems and Linux is about as close as modern Porsches and the Volkswagen Beetle, but either way the two are close enough to get interesting and impressive mashups like this project. For now only time will tell if using XFCE on iOS will be useful for anyone, but other projects bridging the gap between Linux and Apple are sure to be more immediately fruitful.

The Doom computer game rendered with HTML checkboxes

Play DOOM Using Web Browser Checkboxes (Finally)

If you’ve ever felt the need to render DOOM using nothing but web browser checkboxes, [Andrew Healey] has you covered with his recent port of the first-person shooter. Naturally, this gets our tick of approval.

Yes, you read that right. You can now play DOOM in a 160 x 100 grid of HTML-generated checkboxes, much like this: ☑. The secret sauce for this project is partly derived from the fascinating Checkboxland project by fellow hacker Brian Braun, who uses HTML checkboxes to generate a variety of artistic demos.

[Andrew Healey] also made use of Cornelius Diekmann’s port of DOOM using WebAssembly, which we recently covered here on Hackaday. A smattering of code ties both projects together, and the end result is DOOM at 160×100 resolution, rendered entirely with HTML checkboxes.

The port can be played here using Chrome or Edge (other browsers may have issues if they do not support the zoom property in CSS). The source code is also available over on GitHub.

While the resolution and color palette aren’t what we have come to expect from DOOM, it’s likely that the graphics could be further improved by tinkering with the dithering and threshold settings. Higher resolutions may also be possible with further optimization.

We would be hard pressed to pick our favorite port of DOOM, as the list is becoming quite long. However for something completely different, check out our story on how DOOM was brought to Twitter.

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DOOM Played By Tweet

Getting DOOM to run on hardware it was never intended to run on is a tradition as old as time. Old cell phones, embedded systems, and ancient televisions have all been converted to play this classic first-person shooter. This style of playing games on old hardware might be passé now as the new trend seems to be the ability to play this game on more ethereal platforms instead. This project brings DOOM to Twitter.

The gameplay is a little nontraditional as well. To play the game, a tweet needs to be sent with specific instructions for the bot. The bot then plays the game according to its instructions and then tweets a video. By responding to this tweet with more instructions, the player can continue the game tweet-by-tweet. While slightly cumbersome, it does have the advantage of allowing a player to resume any game simply by responding to the tweet where they would like to start. Behind the scenes of the DOOM-playing Twitter bot is interesting as well and the code is available on the project’s GitHub page.

While we’ve seen plenty of DOOM instances on all kinds of hardware, it’s safe to say we’ve never really seen a gameplay experience quite like this one. It may stay as a curiosity, but DOOM porters are always looking for something else to run this classic game so it may eventually branch out or develop into something more user-friendly like this cloud-based Atari 2600.

Charger Caddy Shows What 3D Printers Were Meant For

As computers became more popular in the late 80s and into the 90s, they vastly changed their environments. Of course the technological changes were obvious, but plenty of other things changed to accommodate this new technology as well. For example, furniture started to include design elements to accommodate the desktop computer, with pass-through ports in the back of the desks to facilitate cable management. While these are less common features now there are plenty of desks still have them, this 3D printed design modernizes them in a simple yet revolutionary way.

While these ports may have originally hosted thick VGA cables, parallel printer cables (if they would fit), and other now-obsolete wiring, modern technology uses simpler, smaller solutions. This doesn’t mean that they aren’t any less in need of management, though. This print was designed to hold these smaller wires such as laptop chargers, phone chargers, and other USB cables inside the port. A cap on the top of the print keeps everything hidden until it is lifted by hand, where a cable can be selected and pulled up to the top of the desk.

While it might seem like a simple project at first, the elegance of this solution demonstrates excellent use of design principles and a knack for integrating slightly older design decisions with modern technology. If you have a 3D printer and a cable management port on your desk, the print is available on Thingiverse. Not every project needs a complicated solution to solve a problem, like this automatic solar tracker we recently saw which uses no complicated electronics or algorithms to reliably point itself at the sun.

Clever PCB Brings Micro USB To The Arduino Uno

Even with more and more devices making the leap to USB-C, the Arduino Uno still proudly sports a comparatively ancient Type-B port. It wouldn’t be a stretch to say that many Hackaday readers only keep one of these cables around because they’ve still got an Uno or two they need to plug in occasionally.

Looking to at least move things in the right direction, [sjm4306] recently set out to create a simple board that would let him mount a micro USB connector in place of the Uno’s original Type-B. Naturally there are no components on the PCB, it simply adapts the original through-hole footprint to the tight grouping of surface mount pads necessary to mount a female micro USB port.

Making castellated holes on the cheap.

The design is straightforward, but as [sjm4306] explains in the video below, there’s actually more going on here than you might think. Looking to avoid the premium he’d pay to have the board house do castellated holes, he cheated the system a bit by having the board outline go right through the center of the standard pads.

Under a microscope, you can see the downside of this approach. Some of the holes got pretty tore up as the bit routed out the edges of the board, with a few of them so bad [sjm4306] mentions there might not be enough of the pad left to actually use. But while they may not be terribly attractive, most of them were serviceable. To be safe, he says anyone looking to use his trick with their own designs should order more boards than they think they’ll actually need.

Of course you could go all the way and retrofit the Uno with a USB-C port, as we’ve seen done with devices in the past. But the latest-and-greatest USB interface can be a bit fiddly, especially with DIY gadgets, so we can’t blame him for going with the more reliable approach.

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DOOM On A Bootloader Is The Ultimate Cheat Code

Porting DOOM to run on hardware never meant to run it is a tradition as old as time. Getting it to run on embedded devices, ancient computers, virtual computers, and antique video game consoles are all classic hacks, but what DOOM ports have been waiting for is something with universal applicability that don’t need a bespoke solution for each piece of hardware. Something like DOOM running within a bootloader.

The bootloader that [Ahmad] works with is called Barebox and is focused on embedded systems, often those running Linux. This is the perfect environment for direct hardware access, since the bootloader doubles as a bare metal hardware bring-up toolkit. Now that DOOM runs on this bootloader, it effectively can run anywhere from embedded devices to laptops with minimal work, and although running it in a bootloader takes away a lot of the hard work that would normally need to be done during a port, it may still need some tweaking for specific hardware not otherwise supported.

For those already running Barebox, the bareDOOM code can be found on [Ahmad]’s GitHub page. For those not running Barebox, it does have a number of benefits compared to other bootloaders, even apart from its new ability to play classic FPS games. For those who prefer a more custom DOOM setup, though, we are always fans of DOOM running within an NES cartridge.

Photo: AntonioMDA, CC BY-SA 4.0 via Wikimedia Commons