CPU Made From 74HC Chips Is A Glorious Mess

May 9, 2019 by Inderpreet Singh 35 Comments

Did you ever start a project that you felt gained a life of its own? This project by [Paulo Constantino] is an entire CPU named dreamcatcher on breadboards, and is a beautiful jungle of digital. On top of that, it works to connect to an analog VGA display. How cool is that!

Designing an ALU and then a CPU is a typical exercise for students of digital design and is done using VerilogHDL or VHDL. It involves creating an ALU that can add, subtract etc while a control unit manages data moves and the like. There is also a memory fetch and instruction decode made up of de-mulitiplexers and a bunch of flip-flops that make up registers and flags. They are as complex as they sound if not more.

[Paulo Constantino] went ahead and designed the whole thing in Eagle as a schematic using 74HC logic chips. To build it though instead of a PCB he used breadboards. Everything from bus decoders to controlling an external VGA display is done using jumper wires. We did cover a video on the project a while back, but this update adds a video card interface to the build.

The CPU updates the display buffer on the VGA card, and in the video below shows the slow and steady update. The fact that the jungle of wires can drive a display is awesome. He has since started working on a 16-bit version of the processor and we’d love to see someone take it up a notch.

For those more accustomed to the PCB, the Z80 membership card project is a great build for 8-bit computer fans.

Thanks to [analog engineer] for the tip.

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Add USB-C To Your Laptop (Almost)

May 7, 2019 by Jenny List 24 Comments

It’s a very brave person who takes a Dremel or similar to the case of their svelte new laptop in the quest for a new connector, it sounds as foolhardy as that hoax from a while back in which people tried to drill a 3.5mm jack into their new iPhones. But that’s what [BogdanTheGeek] has done, in adding a USB-C port to his Acer.

Of course, the port in question isn’t a fully functioning USB-C one, it’s a power supply jack, and it replaces the extremely unreliable barrel jack the machine was shipped with. He’s incorporated one of those little “ZYPDS” USB-C power delivery modules we’ve no-doubt all seen in the usual cheap electronic sources, and in a move of breathtaking audacity he’s cut away part of the Acer mainboard to do so. He’s relying on the laptop’s ability to accept a range of voltages, and presumably trusting his steady hand with a rotary tool. Some Kapton tape and a bit of wire completes the work, and with a carefully reshaped hole in the outer case he’s good to go.

The result is beautifully done, and a casual observer would be hard pressed to know that it hadn’t always been a USB-C port. We’re sure there will come a moment at which someone will plug in a USB-C peripheral and expect it to work, it’s that good.

If you’d like to know a little bit more about USB-C, we’d like to direct you to our in-depth look at the subject.

The Cloak Of Invisibility Against Image Recognition

May 3, 2019 by Inderpreet Singh 15 Comments

Adversarial attacks are not something new to the world of Deep Networks used for image recognition. However, as the research with Deep Learning grows, more flaws are uncovered. The team at the University of KU Leuven in Belgium have demonstrated how, by simple using a colored photo held near the torso of a man can render him invisible to image recognition systems based on convolutional neural networks.

Convolutional Neural Networks or CNNs are a class of Deep learning networks that reduces the number of computations to be performed by creating hierarchical patterns from simpler and smaller networks. They are becoming the norm for image recognition applications and are being used in the field. In this new paper, the addition of color patches is seen to confuse the image detector YoLo(v2) by adding noise that disrupts the calculations of the CNN. The patch is not random and can be identified using the process defined in the publication.

This attack can be implemented by printing the disruptive pattern on a t-shirt making them invisible to surveillance system detection. You can read the paper[PDF] that outlines the generation of the adversarial patch. Image recognition camouflage that works on Google’s Inception has been documented in the past and we hope to see more such hacks in the future. Its a new world out there where you hacking is colorful as ever.

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This Week In Security: Facebook Hacked Your Email, Cyber On The Power Grid, And A Nasty Zero-day

May 1, 2019 by Jonathan Bennett 33 Comments

Ah, Facebook. Only you could mess up email verification this badly, and still get a million people to hand over their email address passwords. Yes, you read that right, Facebook’s email verification scheme was to ask users for their email address and email account password. During the verification, Facebook automatically downloaded the account’s contact list, with no warning and no way to opt out.

The amount of terrible here is mind-boggling, but perhaps we need a new security rule-of-thumb for these kind of situations. Don’t ever give an online service the password to a different service. In order to make use of a password in this case, it’s necessary to handle it in plain-text. It’s not certain how long Facebook stored these passwords, but they also recently disclosed that they have been storing millions of Facebook and Instagram passwords in plain-text internally.

This isn’t the first time Facebook has been called out for serious privacy shenanigans, either: In early 2018 it was revealed that the Facebook Android app had been uploading phone call records without informing users. Mark Zuckerberg has recently outlined his plan to give Facebook a new focus on privacy. Time will tell whether any real change will occur.

Cyber Can Mean Anything

Have you noticed that “cyber” has become a meaningless buzz-word, particularly when used by the usual suspects? The Department of Energy released a report that contained a vague but interesting sounding description of an event: “Cyber event that causes interruptions of electrical system operations.” This was noticed by news outlets, and people have been speculating ever since. What is frustrating about this is the wide range of meaning covered by the term “cyber event”. Was it an actual attack? Was Trinity shutting down the power stations, or did an intern trip over a power cord?
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A Physical Knob For Browser Tabs

April 30, 2019 by Brian Benchoff 35 Comments

If you’re like most of us, you have about twenty browser tabs open right now. What if there were a way to move through those tabs with a physical interface? That’s what [Zoe] did, and it’s happening with the best laptop ever made.

The hardware for this build is simply an Arduino and a rotary encoder, no problem there. The firmware on the Arduino simply reads the encoder and sends a bit or two of data over the serial port. This build gets interesting when you connect it to a Firefox extension that allows you to get data from a USB or serial port, and there’s a nice API to access tabs. Put all of this together, and you have a knob that will scroll through all your open tabs.

This build gets really good when you consider there’s also a 3D printed mount, meant to attach to a Thinkpad X220, the greatest laptop ever made. At the flick of a knob, you can scroll through all your tabs. It’s handy if you’re reading three or four or five documents simultaneously, or if you’re just editing video and trying to go through your notes at the same time. A great invention, and we’re waiting for this to become a standard device on keyboards and mice. Check out the video below.

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MIT Cryptographers Are No Match For A Determined Belgian

April 30, 2019 by Jenny List 9 Comments

Twenty years ago, a cryptographic puzzle was included in the construction of a building on the MIT campus. The structure that houses what is now MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) includes a time capsule designed by the building’s architect, [Frank Gehry]. It contains artifacts related to the history of computing, and was meant to be opened whenever someone solved a cryptographic puzzle, or after 35 years had elapsed.

The puzzle was not expected to be solved early, but [Bernard Fabrot], a developer in Belgium, has managed it using not a supercomputer but a run-of-the-mill Intel i7 processor. The capsule will be opened later in May.

The famous cryptographer, [Ronald Rivest], put together what we now know is a deceptively simple challenge. It involves a successive squaring operation, and since it is inherently sequential there is no possibility of using parallel computing techniques to take any shortcuts. [Fabrot] used the GNU Multiple Precision Arithmetic Library in his code, and took over 3 years of computing time to solve it. Meanwhile another team is using an FPGA and are expecting a solution in months, though have been pipped to the post by the Belgian.

The original specification document is a fascinating read, for both the details of the puzzle itself and for [Rivest]’s predictions as to the then future direction of computing power. He expected the puzzle would take the full 35 years to solve and that there would be 10Ghz processors by 2012 when Moore’s Law would begin to tail off, but he is reported as saying that he underestimated the corresponding advances in software.

Header image: Ray and Maria Stata Center, Tafyrn (CC BY 3.0)

A Nearly Practical 6502 Breadboard Computer

April 19, 2019 by Tom Nardi 21 Comments

Over the years we’ve seen a number of homebrew 6502 computers assembled with little more than a breadboard, a sack full of jumper wires, and an otherworldly patience that would make a Buddhist Monk jealous. Anyone who takes the time to assemble a fully functional computer on a half-dozen breadboards lined up on their workbench will always be a superstar in our book.

While we’re still too lazy to attempt one of these builds ourselves, we have to admit that the Vectron 64 by [Nick Bild] looks dangerously close to something you might be able to pull off within a reasonable amount of time. It’s still an incredible amount of work, but compared to some of the other projects we’ve seen, this one manages to keep the part count relatively low thanks to the use of a simple 16×2 LCD for output and user input provided by a PS/2 keyboard. You won’t be playing Prince of Persia on it, but at least you might be able to finish it in a weekend.

The computer is clocked at 1 MHz, and features 32KB RAM
along with 32KB EEPROM. That should be enough for anyone. [Nick] also points out he tried to use era-appropriate 7400 series ICs wherever possible, so no worries about historical revisionism here. If you’re looking for a design that somebody could have potentially knocked together back in the 1970s, this one would get you fairly close.

The astute reader might notice there’s no removable media in this build, and may be wondering how one loads programs. For that, [Nick] allowed himself a bit of modern convenience and came up with a scheme that allows an Arduino (or similar microcontroller) to connect up to the computer’s 28C256-15 EEPROM. With a Python script running on your “real” computer, you can write a new ROM image directly to the chip. He’s included the source code for a simple program which will write whatever you type on the keyboard out on the LCD, which should give you a good framework for writing additional software.

If you’re looking for a bigger challenge, don’t worry. We’ve covered 6502 breadboard computers that will make your eyes water. Incidentally, this isn’t the first time we’ve seen a similar LCD used for one of these computers, so looks like there’s no shame in sneaking in modern parts where it makes sense.