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.

 

Hackaday Prize Entry: Staircane, a Walker That Takes the Stairs

[Jim]’s aunt has lived in the same house for the last 50 years. She loves it there, and she wants to stay as long as possible. There’s a big problem, though. The house has several staircases, and they are all beginning to disagree with her. Enter Staircane, [Jim]’s elegant solution that adds extendable legs to any standard walker.

Most of the time, walkers serve their purpose quite well. But once you encounter uneven ground or a staircase, they show their limitations. The idea behind Staircane is a simple one: quickly extend the back or front legs of a walker depending on the situation, and do so in unison. Staircane uses one button for each set of legs. Pushing the button engages a thin cable, much like the brake cable on a bicycle. The cable pulls a release trigger, unlocking the notched extensions. When the legs are sufficiently extended, the user simply releases the button to lock them in place. Once on flat ground, the user pushes the button again while pressing down on the walker to even out the leg lengths. Check out the video after the break to see the 3D-printed prototype.

Staircane is a semi-finalist in our Wheels, Wings, and Walkers challenge, which ended a few weeks ago. Did you know that you can enter your project into more than one challenge? Since this project falls squarely into assistive technologies territory, we hope that [Jim] and his team submit Staircane to our Assistive Technologies challenge before the deadline on September 4th. We don’t have many entries so far, so if  you’re thinking about entering, give in to temptation!

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How Peptides Are Made

What does body building, anti-aging cream and Bleomycin (a cancer drug) have in common? Peptides of course! Peptides are large molecules that are vital to life. If you were to take a protein and break it into smaller pieces, each piece would be called a peptide. Just like proteins, peptides are made of amino acids linked together in a chain-like structure. Whenever you ingest a protein, your body breaks it down to its individual amino acids. It then puts those amino acids back together in a different order to make whatever peptide or protein your body needs. Insulin, for instance, is a peptide that is 51 amino acids long. Your body synthesizes insulin from the amino acids it gets from the proteins you eat.

Peptides and small proteins can be synthesized in a lab as well. Peptide synthesis is a huge market in the pharmaceutical and skin care industry. They’re also used, somewhat shadily, as a steroid substitute by serious athletes and body builders. In this article, we’re going to go over the basic steps of how to join amino acids together to make a peptide. The chemistry of peptide synthesis is complex and well beyond the scope of this article. But the basic steps of making a peptide are not as difficult as you might think. Join me after the break to gain a basic understanding of how peptides are synthesized in labs across the world, and to establish a good footing should you ever wish to delve deeper and make peptides on your own.

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ESP8266 Based Internet Radio Receiver is Packed with Features

Have a beautiful antique radio that’s beyond repair? This ESP8266 based Internet radio by [Edzelf] would be an excellent starting point to get it running again, as an alternative to a Raspberry-Pi based design. The basic premise is straightforward: an ESP8266 handles the connection to an Internet radio station of your choice, and a VS1053 codec module decodes the stream to produce an audio signal (which will require some form of amplification afterwards).

Besides the excellent documentation (PDF warning), where this firmware really shines is the sheer number of features that have been added. It includes a web interface that allows you to select an arbitrary station as well as cycle through presets, adjust volume, bass, and treble.

 

If you prefer physical controls, it supports buttons and dials. If you’re in the mood for something more Internet of Things, it can be controlled by the MQTT protocol as well. It even supports a color TFT screen by default, although this reduces the number of pins that can be used for button input.

The firmware also supports playing arbitrary .mp3 files hosted on a server. Given the low parts count and the wealth of options for controlling the device, we could see this device making its way into doorbells, practical jokes, and small museum exhibits.

To see it in action, check out the video below:

[Thanks JeeCee]

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The Enigma Enigma: How The Enigma Machine Worked

To many, the Enigma machine is an enigma. But it’s really quite simple. The following is a step-by-step explanation of how it works, from the basics to the full machine.

Possibly the greatest dedicated cipher machine in human history the Enigma machine is a typewriter-sized machine, with keyboard included, that the Germans used to encrypt and decrypt messages during World War II. It’s also one of the machines that the Polish Cipher Bureau and those at Britain’s Bletchley Park figured out how to decipher, or break. Most recently the story of how it was broken was the topic of the movie The Imitation Game.

Let’s start with the basics.

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Self-Playing Violin: Eighth Wonder Of The World

[Martin], of the YouTube channel [WinterGatan], recently uploaded a video tour of the Phonoliszt Violina, an orchestrion, or a machine that plays music that sounds as though an orchestra is playing. The interesting thing about this one is that it plays the violin. At the time of its construction, people weren’t even certain such a thing would be possible and so when [Ludwig Hupfeld] first built one around 1910, it was considered the eighth wonder of the world.

The particular one shown in the video is at the Speelklok Museum in Utrecht, the Netherlands. The bow is a rotating cylinder with 1300 horsehairs. To get the sound of a single violin, it actually uses three of them. Rather than the bow being moved to press against the strings, the violins tilt forward to make their strings contact the rotating bow. Only one string is used per violin, hence the reason that three violins are needed. The volume is controlled by making the bow rotate faster for more volume, and slower for less. Mechanical fingers press against the strings with cork to more closely imitate the human fingertip.

The machine consists of both the mechanical violin and piano under the guidance of two paper rolls, with one roll playing at a time. See and hear it in action in the video below.

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Laser Etching PCBs

A while ago, [Marco] mounted a powerful laser diode to a CNC machine in an attempt to etch copper clad board and create a few PCBs. The results weren’t that great, but the technique was promising. In a new experiment, [Marco] purchased a very cheap laser engraver kit from China, and now this technique looks like it might be a winner.

[Marco] sourced his laser engraver from Banggood, and it’s pretty much exactly what you would expect for a CNC machine that costs under $200. The frame is aluminum extrusion, the motors are off-the-shelf steppers, the electronics are just Pololu-like drivers, and the software is somewhere between abysmal and terrible. Nevertheless, this machine can cut wood, leather, fabric, and can remove spray paint with a big blue laser diode.

To create his PCBs, [Marco] is first cleaning a piece of copper clad board, coating it with spray paint, then blasting it with a laser. The preferred software for this is LaserWeb, and the results are pretty good for a cheap machine.

There are a few extra steps to creating the PCB once the board has been coated with paint and blasted with a laser. This process still requires etching in either ferric chloride or some other mess of acid, but the results are good. So good, in fact, that [Marco] is experimenting with copper foil and Kapton to create flexible circuit boards. You can check out the video of these experiments below.

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