Hackaday Links: November 10, 2019

November 10, 2019 by Dan Maloney 11 Comments

In the leafy suburbs of northern Virginia, a place ruled by homeowner’s associations with tremendous power to dictate everything from the color of one’s front door to the length of grass in the lawn, something as heinous as garage doors suddenly failing to open on command is sure to cause a kerfuffle. We’ve seen this sort of thing before, where errant RF emissions cause unintentional interference, and such stories aren’t terribly interesting because the FCC usually steps in and clears things up. But this story is a little spicier given the source of the interference: Warrenton Training Center, a classified US government communications station located adjacent to the afflicted neighborhood. WTC is known to be a CIA signals intelligence station, home to spooks doing spooky stuff, including running high-power numbers stations. The interference isn’t caused by anything as cloak-and-dagger as that, though; rather, it comes from new land-mobile radios that the Department of Defense is deploying. The new radios use the 380-400 MHz band, which is allocated to the Federal Government and unlicensed Part 15 devices, like garage door remotes. But Part 15 rules, which are clearly printed on every device covered by them, state that the devices have to accept unwanted interference, even when it causes a malfunction. So the HOA members who are up in arms and demanding that the government buy them new garage door openers are likely to be disappointed.

Speaking of spooks, if you’re tired of the prying electronic eyes of facial recognition cameras spoiling your illusion of anonymity, have we got a solution for you. The Opt-Out Cap is the low-tech way to instantly change your face for a better one, or at least one that’s tied to someone else. In a move which is sure not to arouse suspicion in public, doffing the baseball cap deploys a three-piece curtain of semi-opaque fabric, upon which is printed the visage of someone who totally doesn’t look creepy or sketchy in any way. Complete instructions are provided if you want to make one before your next trip to the ATM.

It’s always a great day when a new Ken Shirriff post pops up in our feed, and his latest post is no exception. In it, Ken goes into great detail about the history of the 80×24 (or 25) line standard for displays. While that may sound a bit dry, it’s anything but. After dispelling some of the myths and questionable theories of the format’s origin – sorry, it’s not just because punch cards had 80 columns – he discusses the transition from teletypes to CRTs, focusing on the very cool IBM 2260 Display Station. This interesting beast used an acoustic delay line made of 50′ (15 m) of nickel wire. It stored data as a train of sound pulses traveling down the wire, which worked well and was far cheaper than core memory, even if it was susceptible to vibrations from people walking by it and needed a two-hour warm-up period before use. It’s a fascinating bit of retrocomputing history.

A quick mention of a contest we just heard about that might be right up your alley: the Tech To Protect coding challenge is going on now. Focused on applications for public safety and first responders, the online coding challenge addresses ten different areas, such as mapping LTE network coverage to aid first responders or using augmented reality while extricating car crash victims. It’s interesting stuff, but if you’re interested you’ll have to hurry – the deadline is November 15.

And finally, Supercon starts this week! It’s going to be a blast, and the excitement to hack all the badges and see all the talks is building rapidly. We know not everyone can go, and if you’re going to miss it, we feel for you. Don’t forget that you can still participate vicariously through our livestream. We’ll also be tweet-storming and running a continuous chat on Hackaday.io to keep everyone looped in.

An Atari Graphics Chip, Ready For You To Build

November 10, 2019 by Jenny List 27 Comments

The most notable of the home computer and console hardware from the 8-bit golden era didn’t get their impressive sound and graphics from off-the-shelf silicon, instead they relied on secretive custom chipsets to get the edge over their competitors. Unfortunately for vintage gaming aficionados, those chips are now long out of production and in many cases there’s little information to be had about their operation.

Which makes discovery of the schematics (PDF link) for the “Tia Maria” graphics chip found in the Atari 7800 console an unusual occurrence, and one which should be of special interest to the emulation community. They can be found alongside the rest of the Atari Museum’s 7800 information.

That such a useful document is available at all is due to a lucky find in a dumpster following the demise of Atari, when a treasure trove of documents was discarded. It seems that the existence of these schematics has been known within the Atari community for some time, and we expect before long this information will find its way into FPGA implementations of the 7800; especially since the system features nearly complete backwards compatibility with the massively successful Atari 2600.

When that happens we hope we’ll be able to bring it to you, but it’s not the first time someone’s made an Atari on an FPGA.

Via RetroRGB

Header image: Bilby [CC BY 3.0]

Laser-Based Audio Injection On Voice-Controllable Systems

November 6, 2019 by Pat Whetman 27 Comments

In one of the cooler hacks we’ve seen recently, a bunch of hacking academics at the University of Michigan researched the ability to flicker a laser at audible sound frequencies to see if they could remotely operate microphones simply by shining a light on them. The results are outstanding.

While most Hackers will have heard about ‘The Thing’ – a famous hack where Russian KGB agents would aim a radio transmitter at the great seal in the US embassy, almost none of us will have thought of using lasers shined in from distant locations to hack modern audio devices such as Alexa or Google Assistant. In the name of due diligence, we checked it out on Wikipedia: ‘The Photoacoustic Effect’ , and indeed it is real – first discovered in 1880 by Alexander Bell! The pulsing light is heating the microphone element and causing it to vibrate along with the beam’s intensity. Getting long range out of such a system is a non-trivial product of telescopes, lasers, and careful alignment, but it can be made to work.

Digging deeper into the hack, we find that the actual microphone that is vulnerable is the MEMS type, such as the Knowles SPV0842LR5H. This attack is relatively easy to prevent; manufacturers would simply need to install screens to prevent light from hitting the microphones. For devices already installed in our homes, we recommend either putting a cardboard box over them or moving them away from windows where unscrupulous neighbors or KGB agents could gain access. This does make us wonder if MEMS mics are also vulnerable to radio waves.

As far as mobile phones are concerned, the researchers were able to talk into an iPhone XR at 10 metres, which means that, very possibly, anybody with a hand held ultra violet / infra red equipped flashlight could hack our phones at close range in a bar, for example. The counter-measures are simple – just stick some black electrical tape over the microphone port at the bottom of the phone. Or stay out of those dodgy bars. Continue reading “Laser-Based Audio Injection On Voice-Controllable Systems” →

A DIY Retrocomputer Programmed In Pure Rust

October 21, 2019 by Sharon Lin 17 Comments

Can you generate VGA and handle a PS/2 keyboard with a Cortex-M4 in Rust? That’s precisely what [theJPster] wanted to find out with Monotron, a 1980s style home computer programmed in pure Rust.

In order to run embedded Rust without a working operating system, some tools are necessary: an LLVM back-end for generating machine code, a target file for specifying memory sizes and other configs, and a pre-compiled libcore as a substitute for a compiler when running an operating system. Rust takes the place of C running on top of the board support package (BSP) and hardware abstraction layer (HAL), and peripheral access crates (PACs) that specify the hardware and allow the code to be portable across different chips.

The implementation generates a 800 x 600 VGA video signal at 60 Hz, displays text on a 48 character by 36 line display, displays color graphics using color lookup (stored in flash memory), and runs applications that take less than 24 KiB for all data. Monotron also generates 8-bit audio with PWM and sports a synthesizer that uses a three-channel wavetable allowing it to make sounds with square waves, sine waves, sawtooth waves, and create white noise.

So far, the Monotron has been able to work with an Atari joystick, a PS/2 keyboard, and has outputs to VGA, MIDI, SD card, and audio. Next up for the Monotron: writing a programming language (tentatively named Monotronian), adding support for Sega Megadrive pads, displaying sprites, and many more exciting developments.

Continue reading “A DIY Retrocomputer Programmed In Pure Rust” →

This Week In Security: A Digital Café Américain, The Linux Bugs That Weren’t, The Great Nation, And More

October 18, 2019 by Jonathan Bennett 16 Comments

A government is going after a human rights activists in Morocco. It sounds familiar, but I don’t think Humphrey Bogart is running the gin joint this time around.

Questionable Casablanca references aside, Amnesty International has reported another attack against human rights workers. In this case, a pair of Moroccan activists were targeted with what appears to be NSO’s Pegasus malware suite. Researchers identified text message phishing that led to malicious web pages, as well as HTTP man in the middle attacks against their mobile devices. Once the target was successfully directed to the malicious site, A collection of zero-day vulnerabilities were used to compromise the phone with the NSO malware.

NSO is an Israeli company that specializes in building malware and other cybersecurity tools for governments. As you can imagine, this specialization has earned NSO the scorn of quite a few organizations. NSO claims to have a policy framework in place that allows them to evaluate and terminate the use of their software when it is deemed illegal or abusive, but due to the nature of their contracts, that process is anything but transparent. Continue reading “This Week In Security: A Digital Café Américain, The Linux Bugs That Weren’t, The Great Nation, And More” →

The Smallest Homebrewed TTL CPU In The World

October 16, 2019 by Sharon Lin 16 Comments

This may very well be the smallest homemade TTL CPU we’ve ever seen. Measuring at one square inch, this tiny chip boasts 40 connections, an 8-bit databus, a 16-bit address bus, a 64 kB memory space, reset and clock inputs, and 5 V power lines.

TTL (transistor transistor logic) logic chips are pretty outdated today, but they do have all of the basics necessary for building a computer – logic gates, counters, buffers, and registers. The transistors perform both the logic and amplifying, as compared to resistor-transistor logic (RTL) and diode-transistor logic (DTL). In the 60s, when the technology was still fairly new, TTL ICs were commonly used in computers and industrial controls. Even after the advent of VLSI, TTL ICs were still being used for interfacing more densely integrated chips. Even so, most TTL chips tend to be on the bulkier side, which is what makes [roelh]’s project so unique. The entire PCB is hardly any larger than a coin.

On top of the hardware specs, [roelh] also implemented several useful software features: zero page addressing, load/store/compare instructions, stacks, conditioning branching, subroutine calls, and memory-mapped I/O. The registers are also in RAM, which has been implemented in microprocessors in the past (see TMS9900) for speed considerations, but in this case was implemented for size constraints.

An ALU was also left out of the design in order to constrain its size, leaving only 8 ICs on either side of the 2-layer PCB.

Microprograms are stored in Flash memory and can be programmed with a Raspberry Pi. by saving the Assembly code to a memory card and downloading the assembled binary code. Once the Raspberry Pi is connected to the development board, you can burn the binary code onto the Flash memory of the board using a Python script. An online Javascript editor also exists for assembling the Assembly code for the chip and simulating the CPU.

There is currently a development board made for the CPU, which includes six seven-segment displays and an I/O connector for running a digital clock and other applications. [roelh] has since built a retro TTL computer around the chip, which reintroduces the ALU and includes address registers, 256 KB of RAM, VGA video, PS/2 keyboard port, a sound system, and I/O pins. It’s a really exciting project that’s seriously pushing the constraints of retro computing.