For garden variety daily computing tasks, the floppy disk has thankfully been a thing of the past for quite some time. Slow, limited in storage and easily corrupted, few yearn for the format to return, even if there is some lingering nostalgia for the disks. As it turns out, though, there is still hardware that relies on floppies – namely, the Boeing 747-400, as The Register reports.
The news comes from the work of Pen Test Partners, who recently inspected a 747 being retired as a result of the coronavirus pandemic. The floppy disks are used to load navigational databases which need to be updated regularly, every 28 days. Engineers responsible for loading updates must perform the process manually on the ground.
Efforts have been made in some areas to replace the disks with more modern technology. As Aviation Today covered in 2014, legacy aircraft often require updates involving up to eight floppy disks, leading to slow updates that can cause flight delays. As anyone familiar with the reliability of floppy media knows, it only takes one bad disk to ruin everything. While retrofits are possible, it’s more likely that airlines will simply stick with the technology until the legacy airplanes are retired. Certifying new hardware for flight is a major cost that is difficult to justify when the current system still works.
After seeing the poorly embossed paper maps used in the school, [Sergei] decided there had to be a better way. The solution was 3D printing, which makes producing a map with physical contours easy. Initial attempts involved printing street maps and world maps with raised features, such that students could feel the lines rather than seeing them.
Taking things a step further, [Sergei] went all out, producing an interactive educational device. The build consists of a world map, and contains audio files with information about countries, cultures, and more. When the ultrasonic sensor detects a user in range, it invites them to press or pull out the removable continents on the map. The device can sense touch, thanks to a pair of MPR121 capacitive touch sensor boards which are used to trigger the audio files.
These days, if you’ve got a TV that’s a little too old to directly access streaming services, you’ve got plenty of options. Apple TV, Chromecast, and a cavalcade of Android boxes are available to help get content on your screen. However, if you’re really stuck in the past, ESPFLIX might just be for you.
Yes, that’s right – it’s an online streaming service running on an ESP32. [rossumur] has achieved this feat through a careful use of codecs, and some efficient coding strategies to make it all come together. Video is MPEG1, at just 352×192 resolution. Audio is via the SBC codec, originally intended for use with Bluetooth devices. It’s chosen here for its tiny sample buffers, making it easier to decode in the limited RAM of the ESP32. Output is via composite video, generated on the ESP32 itself.
The titles themselves consist of public domain content, running off an Amazon Web Services instance. With limited RAM on the ESP32, there’s not much buffering to be had, so [rossumur] is bankrolling an AWS Cloudfront instance which should make it possible to use ESPFLIX from most places around the world with a solid internet connection.
Printed circuit boards, they’re a medium designed primarily to mount electrical components with the wires themselves places as copper traces on the boards. To accommodate wide range of needs that have arisen over decades, board houses have evolved all manner of advanced techniques in routing and plating. To our benefit, this also makes it possible to leverage PCBs in an entirely artistic way, taking advantage of the highly-optimized manufacturing process. [GeeekClub] did just that, creating awesome vibrating robots out of custom-made PCBs.
The ‘bots come as a single PCB, with the parts snapped out akin to removing parts from sprues in a plastic model kit. They can then be assembled, with a pair of pager vibration motors installed to provide motive power. But really it’s the aesthetic of the boards and not the functionality that make these so incredible.
The design nestles a coin cell in the base of each bot, providing power and using the weight to help keep them upright. There’s a smattering of LEDs on board, and the art style of the ‘bots draws from Hopi Indian, Asian, and South American influences.
By and large, the Raspberry Pi is a computer that eschews legacy interfaces. Primarily relying on SD cards for storage and USB ports for further expansion, magnetic hard drives are a rare sight. However, [Manawyrm] decided that some 40-pin goodness was in order, and set to making a PATA IDE adapter for the platform.
To achieve the task of interfacing now-vintage IDE devices with the Raspberry Pi, [Manawyrm] elected to use the single board computer’s GPIO pins to get the job done. 23 pins are required, with 16 used for the data bus, with the rest dedicated to address lines, strobes, and other features.
The adapter is no speed demon, netting 800 KiB/s on reads and 500 KiB/s on writes with a Raspberry Pi 4. The main bottleneck comes from relying on libgpiod, which [Manawyrm] readily admits is designed for general IO tasks, not data transfers. Despite this, it’s still fast enough to play an audio CD from an IDE CD-ROM drive without skipping. A kernel build is required, however, as Raspberry Pis are unsurprisingly not configured to use ATA disks by default.
If you’re a human or other animal with two ears, you’ll probably find great utility in your ability to identify the direction of sounds in the world around you. Of course, this is really just a minimal starting point for such abilities. When [John Duffy] set out to build his acoustic camera, he chose to use ninety-six microphones to get the job done.
The acoustic camera works by having an array of microphones laid out in a prescribed grid. By measuring the timing and phase differences of signals appearing at each microphone, it’s possible to determine the location of sound sources in front of the array. The more microphones, the better the data.
[John] goes into detail as to how the project was achieved on the project blog. Outlining such struggles as assembly issues, he also shares information about how to effectively debug the array, and just how to effectively work with so many microphones at once. Particularly impressive is the video of [John] using the device to track a sound to its source. This technology has potential applications in industry for determining the location of compressed air leaks, for example.
Overall, it’s a university research project done right, with a great writeup of the final results. [John]’s project would serve well as a jumping off point for anyone trying to build something similar. Phased array techniques work in RF, too, as this MIT project demonstrates. Video after the break.
Near the turn of the millenium, portable media players like the iPod led to the development of the podcast. The format generally consists of content similar to talk-based radio, and is typically served up in modern codecs like AAC, M4A and MP3. However, [Sean Haas] decided these were all too chunky, and wanted to see if it was possible to deliver similar content on a floppy disk. The results are predictable, but impressive.
[Sean]’s aim was to try and fit roughly 45 minutes of audio on to a 1.44 MB floppy disk. To pull this off, he looked far and wide for a codec fitting for the task. The choice landed on was Adaptive Multi-Rate, or AMR. Typically used to encode audio for GSM phone calls, it can also be used to create compressed audio files.
Initial attempts weren’t quite good enough to do the job, so [Sean] introduced a pre-processing step with FFMPEG, to speed the audio up 1.2 times. It was then passed through SoX and encoded in AMR at approximately 5 kbit/s. This allowed a 45-minute long MP3 file of 72MB to be compressed down into just 1.2 MB, and thus able to fit onto a floppy disk. Audio quality is predictably poor, as you can hear in the embedded clip below, but definitely intelligible. You’d probably want to skip any musical passages if you were doing this seriously.