When you want to read what is being said on a television program, movie, or video you turn on the captions. Looking under the hood to see how this text is delivered is a fascinating story that stared with a technology called Closed Captions, and extended into another called Subtitles (which is arguably the older technology).
I covered the difference between the two, and their backstory, in my previous article on the analog era of closed captions. Today I want to jump into another fascinating chapter of the story: what happened to closed captions as the digital age took over? From peculiar implementations on disc media to esoteric decoding hardware and a baffling quirk of HDMI, it’s a fantastic story.
There were some great questions in the comments section from last time, hopefully I have answered most of these here. Let’s start with some of the off-label uses of closed captioning and Vertical Blanking Interval (VBI) data.
Hackaday editors Elliot Williams and Mike Szczys recount the coolest hacks from the past week. Most clocks keep time with a quartz crystal, but we discuss one that uses a tuning fork… like the kind you use to tune a piano. Ghidra is a powerful reverse engineering tool developed by the NSA that was recently put to good use changing an embedded thermometer display from Celsius to Fahrenheit. We talk turkey on the Texas power grid problems and Tesla’s eMMC failures. And of course there’s some room for nostalgia as we walk down memory lane with the BASIC programming language.
Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Hackaday has among its staff a significant number of writers who also hold amateur radio licenses. We’re hardware folks at heart, so we like our radios homebrew, and we’re never happier than when we’re working at high frequencies.
Amateur radio is a multi-faceted hobby, there’s just so much that’s incredibly interesting about it. It’s a shame then that as a community we sometimes get bogged down with negativity when debating the minutia. So today let’s talk about a few of my favourite things about the hobby of amateur radio. I hope that you’ll find them interesting and entertaining, and in turn share your own favorite things in the comments below.
If you have a pile of old VHS tapes collecting dust in your attic or basement that you know you’ll never watch again, either because all of those movies are available on DVD or a streaming service, or because you haven’t had a working VCR since 2003, there might be a way of putting them to good use in another way. With the miles of tape available in just a few cassettes, [brtv-z] shows us how to use that tape as filament for a 3D printer.
The first step of the build is to actually create the filament. He uses a purpose-built homemade press to spin several tapes into one filament similar to how cotton or flax is spun into yarn. From there the filament is simply fed into the 3D printer and put to work. The tape filament needs to be heated higher than a standard 3D printer filament so he prints at a much slower rate, but the resulting product is indistinguishable from a normal print except for the color. It has some other interesting properties as well, such as retaining its magnetism from the magnetic tape, and being a little more brittle than PET plastic although it seems to be a little stronger.
While the VHS filament might not be a replacement for all plastic 3D prints, it’s still a great use for something that would likely otherwise head straight to the landfill. There are some other uses for this magnetic tape as well, like if you wanted to build a DIY particle accelerator.
To get started, [Daniel] fitted X-acto blades to a brushless outrunner motor, and tested their ability to cut grass. Satisfied with the performance, he built a trailer to tow behind an RC tank mounted to such a setup, with some success. With the concept beginning to bear fruit, he went with a clean sheet design for maximum performance.
The final build relies on an RC rock-crawler chassis, fitted with a brushless motor using field oriented control for maximum torque at low speeds. This allows the RC mower to slowly push through the grass without overwhelming the cutter heads. As for the cutter heads, the final rig has eight motors, each sporting two blades to chop down long field grasses with impunity.
I’m moving, and in the process of packing all of my belongings into storage boxes to disappear into a darkened room for the next year. Perhaps I could become one of those digital nomads I hear so much about and post my Hackaday stories from a sun-kissed beach while goldfish shoals nibble at my toes. But here in a slightly damp British autumn, box after box of a lifetime’s immersion in tech needs sorting and directing. Why on earth did I hang on to three Philips N1500 VCR system video cassette recorders from the early 1970s! (Don’t worry, those have found a good home.)
Say Hello To An Old Friend Of Mine
Instantly recognisable, the AVO 8
As I was packing up my bench, I happened upon a multimeter. I have quite a few multimeters and this isn’t the first time I’ve written about these indispensable instruments, but this one’s a little special.
It’s a treasure from my youth, that most venerable of British test equipment: the AVO 8. This was the ubiquitous multimeter to be found in all manner of electrical and electronic workshops across most of the 20th century, and remains to this day one of the highest quality examples of its type.
It’s a relatively huge Bakelite box about 190mm x 170mm x 100mm in size, and it is instantly recognisable by its dual rotary selector switches and the window for viewing the needle, which forms a characteristic circular arc kidney shape.
The earliest ancestors of my meter appeared in the 1920s, and the first model 8 in the early 1950s. Mine is a Mk III that a penciled date on the inside of its meter movement tells me was made in November 1965 and which I bought reconditioned from Stewart of Reading in about 1991, but manufacture continued until the last Mk VIII rolled off the production line in 2008. It’s to my shame that my AVO is a bit dusty and that maybe I haven’t used it much of late, but as I picked it up all the memories of using it to fix dead TV sets and set up optimistic experiments in radio came flooding back. If there’s one instrument that connects me to the youthful would-be electronic engineer that I once was, then here it is. Continue reading “Ode To An AVO 8 Multimeter”→
Microsoft has just announced a way to disable JScript in Internet Explorer. This would have been very useful a few years ago, to proactively prevent problems found in the now-ancient JScript engine, which ran their own slightly different version of standard JavaScript. Even though IE is no longer under active development, it still receives security updates. JScript, on the other hand, is basically done. If you’re one of the 1.06% that still use IE, then go flip the switch to protect yourself from additional JScript vulnerabilities.
Zerologon and Samba?
Samba is an open source re-implemenation of Microsoft’s SMB protocol. There’s a clever term that describes the reality of this situation: “Bug for bug compatibility”. Remember Zerologon, the flaw where a security token’s generation could be manipulated to vastly reduce the key space? Samba follows the specification, and therefore suffers from the same issue, though it seems to be unusual to actually run Samba in a vulnerable configuration.
