Fake Ram: Identifying a Counterfeit Chip

[Robert Baruch‏] had something strange on his hands. He had carefully decapped 74LS189 16×4 static RAM, only to find that it wasn’t a RAM at all. The silicon die inside the plastic package even had analog elements, which is not what one would expect to find in an SRAM. But what was it? A quick tweet brought in the cavalry, in the form of chip analysis expert [Ken Shirriff].

[Ken] immediately realized the part [Robert] had uncovered wasn’t a 74 series chip at all. The power and ground pins were in the wrong places. Even the transistors were small CMOS devices, where a 74 series part would use larger bipolar transistors. The most glaring difference between the mystery device and a real LS819 was the analog elements. The mystery chip had a resistor network, arranged as an R-2R ladder. This configuration is often used as a simple Digital to Analog Converter (DAC).

Further analysis of the part revealed that the DAC was driven by a mask ROM that was itself indexed using a linear feedback shift register. [Ken] used all this information to plot out the analog signal the chip would generate. It turned out to be a rather sorry looking sine wave.

The mystery part didn’t look like any function generator or audio chip of the era. [Ken] had to think about what sort of commodity part would use lookup tables to generate an audio waveform. The answer was as close as his telephone — a DTMF “touch tone” generator, specifically a knockoff of a Mostek MK5085.

Most investigators would have stopped there. Not [Ken] though. He delved into the construction and function of the DTMF generator. You can find the full analysis on his site. This isn’t [Ken’s] first rodeo with decapped chips. He’s previously examined the Intel 8008 and presented a talk on silicon reverse engineering at the 2016 Hackaday Superconference. [Robert] has also shown us how to pop the top of classic ceramic integrated circuits.

 

Amphibious Houseboat Hits the Open Road

What’s better than having your own houseboat? How about an amphibious houseboat? That’s exactly what [Theon Parseghian] is building in his driveway. It all started with a derelict 32-foot long houseboat. A 1967 model with a rusted steel hull, [Theon] originally bought it as a guest house.

[Theon] couldn’t let the boat rust away in his back yard though. Quickly decided to get it back on the open water…. and on the road. An amphibious houseboat. While looking for large tractor tires, [Theon] found an entire crop sprayer which hadn’t been used in years. This crop sprayer was a giant tricycle wheeled monster, with huge spray arms.

The original plan was to carve out a hole for the sprayer, and essentially drop the boat on the sprayer chassis. Things never quite work out as planned though. The sprayer was a bit too short, so it’s chassis was replaced with one from a school bus. The axle wasn’t quite long enough to clear the boat’s draft, so it was extended with custom steel wheel spacers.

The build is documented in a 7 part series on YouTube. The latest episode details the boat’s first drive under its own power. We’re not sure how street legal an amphibious houseboat would be, but [Theon] doesn’t have too far to drive, as there is a large lake just behind his shop in Upstate New York. The houseboat launches on August 23. Good luck [Theon]!

If a houseboat is too big for you, how about a barrel boat. If you’re into tiny boats, you could cross the Atlantic with a 42-inch vessel.

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Wearable Superconductors

What do you do with a discarded bit of superconducting wire? If you’re [Patrick Adair], you turn it into a ring.

Superconducting wire has been around for decades now. Typically it is a thick wire made up of strands of titanium and niobium encased in copper. Used sections of this wire show up on the open market from time to time. [Patrick] got ahold of some, and with his buddies at the waterjet channel, they cut it into slices. It was then over to the lathe to shape the ring.

Once the basic shape was created, [Patrick] placed the ring in ferric chloride solution — yes the same stuff we use to etch PC boards. The ferric chloride etched away just a bit of the copper, making the titanium niobium sections stand out. A trip through the rock tumbler put the final finish on the ring. [Patrick] left the ring in bare metal, though we would probably add an epoxy or similar coating to keep the copper from oxidizing.

[Patrick] is selling these rings on his website, though at $700 each, they’re not cheap. Time to hit up the auction sites and find some superconducting wire sections of our own!

If you’re looking to make rings out of more accessible objects, check out this ring made from colored pencils, or this one made from phone wire.

DC Motor Whirligig Generates Power

Everyone knows that if you spin the shaft of a DC motor, it will generate power. [Vapsvus] has found a novel way to do this with no direct mechanical connection to the shaft. He simply taped a loop of string around to the motor can. This effectively turns the motor into a whirligig. Flip the motor to give the string a few twists, then pull on the two loops. The string unwinds and then winds back up, just like the toy we all grew up with.

The interesting thing is that the motor generates usable power when being spun like this. [Vapsvus] connected two LEDs to the motor’s leads to show what’s happening. The white LED glows when current travels from positive to negative, and the red LED glows when current travels from negative to positive.

What’s going on under the hood is all about momentum. As the motor can starts to spin, the heavy iron rotor remains still. Power is generated. Eventually, friction and torque from back EMF cause the rotor to spin as well. By the time the rotor is spinning, the motor can is already reversing direction.This generates even more power with current traveling in reverse.

Sure, this isn’t exactly practical, but we’d love to see how far it could be taken. Add a super capacitor, and we bet it would be more efficient than the magnetic shake lights which were popular a few years back.

Whirligigs are usefully little devices. Not only do they keep children entertained, you can use them as centrifuges.

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Charge Your Phone on an Iron Throne

Game of Thrones season 7 is finally here! [Hoecrux] is celebrating by building a GoT inspired cell phone charger. No, this isn’t a 3D print, nor is it vacuum molded. This iron throne was hand made from hundreds of cocktail swords. The frame of the chair is made from medium density fiberboard (MDF). The frame is covered with upholstery foam, then a layer of thin gray foam which forms the surface of the chair.

[Hoecrux] then began the painstaking process of hot gluing 600 cocktail swords to her creation. Each sword had to be modified by cutting off the loop guard. Some of the swords are bent, which was achieved with a heat gun. The completed chair was finished with a coat of black spray paint, followed by dry brushing with acrylic silver paint.

This particular iron throne charger is built for an android phone. [Hoecrux] embedded a micro USB cable in the base of the seat. If you’re of the iOS persuasion, you can substitute a lightning cable.

Check out the video after the link, and while you’re at it, get a look at this beach ready solar charger setup.

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Books you should read: The Bridge

A few weeks ago, Amazon’s crack marketing AI decided to recommend a few books for me. That AI must be getting better because instead of the latest special-edition Twilight books, I was greeted with this:

“The asteroid was called the Hand of God when it hit.”

That’s the first sentence of The Bridge, a new Sci-Fi book by Leonard Petracci. If you think that line sucks you in, wait until you read the whole first chapter.

The Bridge is solidly in the generation ship trope. A voyage hundreds or even thousands of years long, with no sleep or stasis pods. The original crew knows they have no hope of seeing their destination, nor will their children and grandchildren. Heinlein delved into it with Orphans of the Sky. Even Robert Goddard himself discussed generation ships in The Last Migration.

I wouldn’t call The Bridge hard Sci-Fi — and that’s perfectly fine. Leonard isn’t going for scientific accuracy. It’s a great character driven story. If you enjoyed a book like Ready Player One, you’ll probably enjoy this.

The Bridge Is the story of Dandelion 14, a ship carrying people of Earth to a new planet. At some point during the journey, Dandelion 14 was struck by an asteroid, which split the ship in two. Only a few wires and cables keep the halves of the ship together. The crew on both sides of the ship survived, but they had no way to communicate. They do catch glimpses of each other in the windows though.

Much of the story is told in the first person by Horatius, a young man born hundreds of years after the asteroid strike. Horatius’ side of the ship has a population of one thousand, carefully measured at each census. They’ve lost knowledge of how to operate the ship’s systems, but they are surviving. Most of the population are gardeners, but there are doctors, cooks, porters, and a few historians. At four years old, Horatius is selected to become a gardener, like his father was before him. But Horatius has higher aspirations. He longs to become a historian to learn the secrets of the generations that came before him and to write his own story down for those who will come after.

Horatius sees the faces of the people on the other side of the ship as well. Gaunt, hungry, often fighting with knives or other weapons. A stark contrast to the well-fed people on his side of the vessel. The exception is one red-haired girl about his age. He often finds her staring back at him, watching him.

Horatius might have been chosen as a gardener, but he’s clever — a fact that sometimes gets him in trouble. His life takes an abrupt turn when the sleeping ship awakens with an announcement blaring “Systems Rebooting, Ship damage assessed. Reuniting the two halves of the ship and restoring airlock, approximately twenty-four hours until complete.”

The hardest part of writing a book review is not giving too much away. While I won’t tell you much more about the plot for The Bridge, I can tell a bit about how the book came about. You might call this book a hack of the publishing system. Leonard Petracci is also known as leoduhvinci on Reddit. The Bridge started life as Leonard’s response to a post on /r/writingprompts. The prompt went like this:

After almost 1,000 years the population of a generation ship has lost the ability to understand most technology and now lives at a pre-industrial level. Today the ship reaches its destination and the automated systems come back online.

Leonard ’s response to the prompt shot straight to the top, and became the first chapter of The Bridge. Chapter 2 followed soon after. In only a few months, the book was complete. Available on Reddit, and on Leonard’s website. The Bridge is also available on Amazon for Kindle, and on paper from Amazon’s CreateSpace.

The only real criticism I have about The Bridge is the ending. The book’s resolution felt a bit rushed. It would have been nice to have a few more pages telling us what happened to the characters after the major events of the book. Leonard is planning a sequel though, and he teases this in the final pages.

You can start reading The Bridge right now on Leonard’s website. He has the entire book online for free for a few more weeks. If you’ve missed the free period, the Kindle edition is currently $2.99.

eMMC to SD Hack Rescues Data from a Waterlogged Phone

How do I get the data off this destroyed phone? It’s a question many of us have had to ponder – either ourselves or for friends or family. The easy answer is either spend a mint for a recovery service or consider it lost forever.  [Trochilidae] didn’t accept either of those options, so he broke out the soldering iron and rescued his own data.

A moment’s inattention with a child near a paddling pool left [Trochilidae’s] coworker’s wife with a waterlogged, dead phone. She immediately took apart the phone and attempted to dry it out, but it was too late. The phone was a goner. It also had four months of photos and other priceless data on it. [Trochilidae] was brought in to try to recover the data.

The phone was dead, but chances are the data stored within it was fine. Most devices built in the last few years use eMMC flash devices as their secondary storage. eMMC stands for Embedded Multimedia Card. What it means is that the device not only holds the flash memory array, it also contains a flash controller which handles wear leveling, flash writing, and host interface. The controller can be configured to respond exactly like a standard SD card.

The hard part is getting a tiny 153 ball BGA package to fit into an SD card slot.  [Trochilidae] accomplished that by cutting open a microSD to SD adapter. He then carefully soldered the balls from the eMMC to the pins of the adapter. Thin gauge wire, a fine tip iron, and a microscope are essentials here. Once the physical connections were made,  [Trochilidae] plugged the card into his Linux machine. The card was recognized, and he managed to pull all the data off with a single dd command.

[Trochilidae] doesn’t say what happened after the data was copied, but we’re guessing he analyzed the dump to determine the filesystem, then mounted it as a drive. The end result was a ton of recovered photos and a very happy coworker.

If you like crazy soldering exploits, check out this PSP reverse engineering hack, where every pin of a BGA was soldered to magnet wire.