Vacuum Tubes: Shipping Through EBay Now Challenging?

January 20, 2018 by Jenny List 76 Comments

There is disquiet in the world of vacuum electronics, that something as simple as shipping a vacuum tube could now be very difficult to achieve. It’s a concern expressed among other places in a video by [Guitologist] that we’ve included below, and includes tales of vacuum tubes being impounded as either dangerous to ship, or not allowed to be shipped across international borders.

Upon investigation it appears that the common thread in all the stories lies with eBay’s Global Shipping Program, the centralised shipping service operated by the online auction giant. We reached out to eBay’s press office on the subject but have yet to receive a reply. It’s best to ask someone who ships a lot of tubes for comment when you have a tube shipping story, so we also had a conversation with TC Tubes. They’re a small company dealing in tubes, and as you might imagine they ship a lot of them (Their website is likely to detain you for a while if you are a tube-head). [Chelsea] from TC Tubes told us that they have encountered no regulatory barriers to tube shipping, and that their only bad experience has been yet again with eBay’s Global Shipping Program.

So it seems there is no cause for panic if you ship tubes, CE marking or RoHS rules haven’t come for your EL34s and your 6550s. Ebay have evidently got some kind of issue with tubes in their shipping operation, and perhaps you should ship by other means if you wish to avoid your tubes going astray. The consensus here among the Hackaday crew is that it could be as simple as uninformed employees not being aware of what tubes are because they aren’t as common as they used to be. After all, with over a hundred years of history behind them it’s not as though any potential issues with their shipping haven’t been comprehensively explored.

We’d still be interested to hear from eBay on the matter though, if they would care to comment.

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Getting To Know An 18th Century Hacker

January 19, 2018 by Tom Nardi 11 Comments

Here at Hackaday we tend to stay pretty close to the bleeding edge in tech, not by any conscious effort, but simply because that’s what most hackers are interested in. Sure we see the occasional vintage computer rebuild, or reverse engineering of some component that was put into service before most of us were born; but on the whole you’re way more likely to see projects involving the latest and greatest microcontroller to hit AliExpress than ones involving the once ubiquitous vacuum tube.

But occasionally it’s nice to take a step back from the latest and greatest, to really look at what makes the hacker spirit without the all modern trappings of blinking LEDs and Wi-Fi connectivity. We make and explore because it’s something we are passionate about, and while today most of us are doing that with a soldering iron or a compiler, that hasn’t always been the case. In the video below, historic interpreter and woodworker [Bill Maddox] talks about what draws him to 18th century technology. His tools may look foreign to us, but the passion he shows while talking about his creations will be familiar to anyone who’s ever set foot in a hackerspace.

Even with a vastly different set of interests than the modern hacker, [Bill] runs into some very familiar problems. When the highly specialized tools he needed to work like an 18th century craftsman weren’t available, he decided to make his own. But to make his own tools he needed to learn how to forge, and after he forged his hand tools he moved on to forging chisels for the lathe he decided to build.

Whether or not we ever take a knife to a piece of wood and try to carve out a spoon, it’s impossible to watch [Bill] speak about his creations and not see him as a kindred spirit. Like many of us, he’s honed skills in a niche that the everyday person takes for granted. Makes you wonder what people from 300 years in the future would think of us if they could peer back through the centuries.

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Reading Out An EPROM – With DIP Switches

January 18, 2018 by Sven Gregori 10 Comments

We’re all too spoiled nowadays with our comfortable ways to erase and write data to persistent memory, whether it’s our microcontroller’s internal flash or some external EEPROM. Admittedly, those memory technologies aren’t exactly new, but they stem from a time when their predecessors had to bathe under ultraviolet light in order to make space for something new. [Taylor Schweizer] recently came across some of these quartz-window decorated chips, and was curious to find out what is stored in them. Inspired by the BIOS reverse engineering scene in Halt and Catch Fire, he ended up building his own simple reader to display the EPROM’s content.

The 2732 he uses is a standard EPROM with 32kbit memory. Two pins, Chip Enable and Output Enable, serve as main control interface, while 12 address pins select the data stored in the chip’s internal 4K x 8 arrangement, to output it on the 8 data output pins. You could of course hook up the EPROM to a microcontroller and send what you read via serial line, but [Taylor] opted for a more hands-on approach that lets him read out the data in a manual way. He simply uses a bank of DIP switches to set the address and control pins, and added a row of LEDs as display.

As you can see from the short demonstration in the video after the break, reading out the entire EPROM would be a rather tedious task this way. If you do have more serious intentions to read out the content, you could have a look at one of those microcontroller based solutions sending data via serial line after all.

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Improvising An EPROM Eraser

January 17, 2018 by Brian Benchoff 86 Comments

Back in the old days, when we were still twiddling bits with magnetized needles, changing the data on an EPROM wasn’t as simple as shoving it in a programmer. These memory chips were erased with UV light shining through a quartz window onto a silicon die. At the time, there were neat little blacklights in a box sold to erase these chips. There’s little need for these chip erasers now, so how do you erase and program a chip these days? Build your own chip eraser using components that would have blown minds back in the 70s.

[Charles] got his hands on an old 2764 EPROM for a project, but this chip had a problem — there was still data on it. Fortunately, old electronics are highly resistant to abuse, so he pulled out the obvious equipment to erase this chip, a 300 watt tanning lamp. This almost burnt down the house, and after a second round of erasing of six hours under the lamp, there were still unerased bits.

Our ability to generate UV light has improved dramatically over the last fifty years, and [Charles] remembered he had an assortment of LEDs, including a few tiny 5mW UV LEDs. Can five milliwatts do what three hundred watts couldn’t? Yes; the LED had the right frequency to flip a bit, and erasing an EPROM is a function of intensity and time. All you really need to do is shine a LED onto a chip for a few hours.

With this vintage chip erased, [Charles] slapped together an EPROM programmer — with a programming voltage of 21V — out of an ATMega and a bench power supply. It eventually worked, allowing [Charles]’ project, a vintage liquid crystal display, to have the right data using vintage-correct parts.

Joykill: Previously Undisclosed Vulnerability Endangers User Data

January 17, 2018 by Brian Benchoff 28 Comments

Researchers have recently announced a vulnerability in PC hardware enabling attackers to wipe the disk of a victim’s computer. This vulnerability, going by the name Joykill, stems from the lack of proper validation when enabling manufacturing system tests.

Joykill affects the IBM PCjr and allows local and remote attackers to destroy the contents of the floppy diskette using minimal interaction. The attack is performed by plugging two joysticks into the PCjr, booting the computer, entering the PCjr’s diagnostic mode, and immediately pressing button ‘B’ on joystick one, and buttons ‘A’ and ‘B’ on joystick two. This will enable the manufacturing system test mode, where all internal tests are performed without user interaction. The first of these tests is the diskette test, which destroys all user data on any inserted diskette. There is no visual indication of what is happening, and the data is destroyed when the test is run.

A local exploit destroying user data is scary enough, but after much work, the researchers behind Joykill have also managed to craft a remote exploit based on Joykill. To accomplish this, the researchers built two IBM PCjr joysticks with 50-meter long cables.

Researchers believe this exploit is due to undocumented code in the PCjr’s ROM. This code contains diagnostics code for manufacturing burn-in, system test code, and service test code. This code is not meant to be run by the end user, but is still exploitable by an attacker. Researchers have disassembled this code and made their work available to anyone.

As of the time of this writing, we were not able to contact anyone at the IBM PCjr Information Center for comment. We did, however, receive an exciting offer for a Carribean cruise.

DIY Bookshelf Is More Than Meets The Eye

January 14, 2018 by Tom Nardi 28 Comments

It might surprise you, Dear Reader, that not every project featured on Hackaday needs to pulsate with LEDs, or update the world about its goings-on over Twitter. They don’t even, contrary to what you may have heard, need to have an Arduino inside. No, sometimes you can pull off a pretty neat hack with nothing more than some wood, a couple of tools, and a unique idea which repurposes something that would otherwise be in a landfill.

Such is the case with the latest project from [Keith Decent], which uses plywood and the spines of old books to create a secret compartment “bookshelf”. The concept is probably best described as a roll-top desk on its side, and while the action does appear a little stiff, it scores extra points for how easy it looks to replicate.

Using a router, [Keith] cuts a channel into the top and bottom sheets of plywood, which the “books” will eventually ride in. This channel goes around the entire perimeter of the shelf, and it’s important to make it as straight as possible so nothing binds up. To make sure things move through as smoothly as possible, some sandpaper is used to clean-up the inside edges.

The next step is to rip some books apart and salvage their spines. Used books can be purchased for next to nothing at flea markets, so even if you don’t have a home library filled with vintage tomes to eviscerate, it should be easy enough to get your hands on some if you want to build your own version. For sanity’s sake it would seem that books with the same size spines are ideal, so keep an eye out for old sets of encyclopedias and the like.

When the spines are removed from the books, they get glued to individual wooden slats. These slats then have holes drilled in the top and bottom, and standard wood screws driven in to act as “rollers”. Real rollers would undoubtedly make for smoother action, but you can’t beat his method if you’re trying to get it done cheaply and quickly.

The slats are then glued onto a piece of fabric, creating what is referred to as a tambour. The fabric backing links all the slats together and makes it so that pushing and pulling one slat will move them all together as one. The book spine tambour is then inserted in the routed channel, and the back panel of the shelf can be installed to lock it all together.

At this point the project is essentially done, but [Keith] does take it the extra mile by sealing all the book spines and doing some finish work on the shelf to make it look more like a real vintage piece of furniture instead of some scrap plywood screwed together.

If this exercise in woodworking has gotten you interested in the wonderful world of dead trees, you’re in luck. We’ve covered several woodworking projects from the hacker perspective, so you won’t be completely lost.

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Bartop Arcade Cabinet Build Skips The Kit

January 14, 2018 by Tom Nardi 7 Comments

An arcade cabinet is one of those things that every gamer wants at home, but few ever get. Getting a real arcade cabinet is usually expensive, and building one yourself is no small feat. There are kits you can get now which help the process along, generally taking the form of pre-cut cabinet parts, but with them comes the quiet shame of kit-building. What if your friends found out you used a kit instead of designing it yourself? The drama is almost too much to think about.

That’s how [Bogdan Berg] felt about it, at least. Not content with just getting a pre-cut cabinet kit from eBay, he decided to design and build his own bartop arcade machine in just one week: fast enough for him to fit the whole thing into his Christmas vacation. We don’t know what Christmas was like for his friends and family this year with him toiling away on this beautiful build the whole time, but we can confidently say his Christmas was awesome.

He designed the cabinet in Fusion 360, working around the limitation that the laser cutter he had access to had a work area of 24 inches by 18 inches. Some interesting design choices were made here, including going with a tab and slot construction method. While [Bogdan] admits that this aesthetic isn’t always popular, he liked how sturdy it makes the final product.

He was originally going to use plywood for the cabinet, but owing to the fact that he couldn’t find any pieces that weren’t warped locally, he switched over to MDF. Using MDF did mean he had to seal all the cut pieces with shellac before painting, but in the end he’s happy with the final lacquer paint job; even if it did take more work and materials than he anticipated.

The hardware is pretty much the standard for DIY arcades these days: a 17 inch LCD monitor he had laying around is used for the display, a two player joystick and button kit from Amazon provides the user interface, and emulation is provided by a Raspberry Pi 3 running RetroPie. A recessed door in the rear allows him to get into the machine will still maintaining a finished look on the backside.

While the size of them may vary wildly, DIY arcade cabinets are always a popular project. Whether shamelessly emblazoned with our logo or playing host to glorious LED lighting, it seems like the design of these cabinets provide as much entertainment as the games they play.

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