Building A Replica Of An Obscure Romanian Computer

September 29, 2022 by Lewin Day 5 Comments

We’ve all seen emulated Apple II and Commodore 64 boards about the place. Few of us have heard of the Romanian ZX Spectrum clone known as the Cobra, let alone any efforts to replicate one. However, [Thomas Sowell] has achieved just that, and has shared the tale with us online.

The Cobra was named for its origins in the city of Brasov – hence, COmputer BRasov. The replica project was spawned for a simple reason. Given that sourcing an original Romanian Cobra would be difficult, [Thomas] realized that he could instead build his own, just as many Romanians did in the 1980s. He set about studying the best online resources about the Cobra, and got down to work.

The build started with board images sourced from Cobrasov.com, and these were used to get a PCB made. [Thomas] decided to only use vintage ICs sourced from the Eastern Bloc for authenticity’s sake, too. Most came from the former USSR, though some parts were of East German, Romanian, or Czechoslovakian manufacture. The project took place prior to the Russian invasion of Ukraine, so there weren’t any hassles shipping across borders.

With everything hooked up and the EEPROMs given a real Cobra ROM image, the computer burst into life. There were some hiccups, with an overheating video IC and some memory glitches. However, with some nifty tweaks and replacements subbed in, the computer came good. Other work involved adding a custom keyboard and modifying 3.5″ floppy drives to work with the system.

Overall, the build is a faithful tribute to what was an impressive piece of engineering from behind the Iron Curtain. [Thomas]’s work also embodies the DIY ethos behind many homebrew Cobra computers built back in the day.

If all this talk has got you curious about the full history of the Cobra and Romania’s underground computer movement, we have everything you’re looking for right here!

Teardown: Cobra XRS 9740 Radar Detector

March 18, 2020 by Tom Nardi 46 Comments

Drivers with a lead foot more often than not have Waze open on their phone so they can see if other drivers have spotted cops up ahead. But avoiding a speeding ticket used to involve a lot more hardware than software. Back before the smartphone revolution, that same driver would have had a radar detector on their dashboard. That’s not to say the gadgets are completely unused today, but between their relatively high cost (one of the top rated models on Amazon as of this writing costs over $300) and the inevitable false positives from so many vehicles on the road having their own radar and LIDAR systems, they’ve certainly become a less common sight over the years

The subject of today’s teardown is a perfect example of “Peak Radar Detector”. Manufactured back in 2007, the Cobra XRS 9740 would have been a fairly mid-range entry offering the sort of features that would have been desirable at the time. Over a decade ago, having an alphanumeric display, voice alerts, and a digital compass were all things worth shouting about on the box the thing was sold in. Though looking like some kind of Cardassian warship was apparently just an added bonus.

As the name implies these devices are primarily for detecting radar activity, but by this point they’d also been expanded to pick up infrared lasers and the strobe beacons on emergency vehicles. But false positives were always a problem, so the device allows the user to select which signals it should be on the lookout for. If you were getting some kind of interference that convinced the detector it was being bombarded with IR lasers, you could just turn that function off without having to pull the plug entirely.

But it’s important to remember that this device was built back when people were still unironically carrying around flip phones. Detecting laser and multi-band radars might sound like something pulled from the spec sheet of a stealth fighter jet, but this is still a piece of consumer electronics from more than a decade in the past. So let’s crack it open and take a look at what goes on inside a radar detector that’s only a few years away from being old enough to get its own driver’s license.

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Ever Hear Of The Ford Cylon?

May 25, 2017 by Jamie Navarro 42 Comments

OK, we haven’t heard of a Ford Cylon either. However, there is now a Mustang Cobra out there that has been given a famous Cylon characteristic. [Monta Elkins] picked himself up an aftermarket third brake light assembly, hacked it, and installed it on said Mustang.

The brake light assembly contains 12 LEDs, which unfortunately, are not individually addressable. Additionally, by the looks of it, the brake light housing was not meant to be opened up. That didn’t get [Monta] down though. There’s more than one way to skin a cat, but he chose to use a hot knife to open the assembly, which worked quite well. A rotary cutter tool was used to cut the traces between the LEDs allowing them to be individually controlled with an Arduino. A Bluetooth module allows him to control the new brake light from his smartphone. There are different modes (including a special mode that he shows off at the end of the video) that can be selected via a Bluetooth Terminal app.

There is no schematic or code link in the video itself or the description, but [Monta] did hit the high points. Therefore, it shouldn’t be too hard to replicate.

This isn’t the first brake light hack we’ve featured. This one goes way beyond just animated lights. This one requires no programming. Rather wear your brake light? We’ve got your back(pack).

A Charming Arduino King Cobra Game

June 22, 2013 by Brian Benchoff 22 Comments

cobra

Here’s a fun game from [A.J.]’s lab. It’s a simulated king cobra made from an Arduino, an ultrasonic sensor, and a servo. The aim of the game is to grab a ball in front of the device without being ‘bitten’ by the thumbtack attached to a drinking straw controlled by a servo. You know, just like a real king cobra.

There’s no schematic or build plans for this project, but it looks easy enough to cobble together. Despite its simplicity, this game looks hilariously fun, and could quite possibly provide more entertainment through using the machine rather than simply building it.

No text description of this game can do it justice, so check out the video below. It looks like a lot of fun, and if you already have the parts in a bin somewhere, it’ll make a great weekend build.

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$4500 Book About A Car You Can’t Afford

October 9, 2009 by Mike Szczys 24 Comments

The folks over at Kirkham Motorsports have turned out two things of beauty. The first is a sky’s-the-limit milled aluminum car. The second is a book about the making of the car that runs $4500 per copy. Why so much for a book? The binding is milled out of a 35 pound aluminum billet.

The project spans a 2 1/2 year build cycle and showcases the gamut of craftsmanship. The extremely detailed build log is available at their website in PDF form. Of particular interest to us is Chapter 10: Milling. The sheer volume of machined parts for this roadster is mind-boggling. There’s also plenty of CNC pipe bending involved with the body work in Chapter 18.

Finish up your work this morning and spend the rest of the day with this fantasy creation. If you’ve got too much to do, why not shell out for the hard-copy version and devote your weekend to metal-working romance?

[via Makezine]