Hackaday Links: April 5, 2020

Git is powerful, but with great power comes the ability to really bork things up. When you find yourself looking at an inscrutable error message after an ill-advised late-night commit, it can be a maximum pucker-factor moment, and keeping a clear enough head to fix the problem can be challenging. A little proactive social engineering may be in order, which is why Jonathan Bisson wrote git-undo, a simple shell script that displays the most common un-borking commands he’s likely to need. There are other ways to prompt yourself through Git emergencies, like Oh Shit, Git (or for the scatologically sensitive, Dangit Git), but git-undo has the advantage of working without an Internet connection.

Suddenly find yourself with a bunch of time on your hands and nothing to challenge your skills? Why not try to write a program in a single Tweet? The brainchild of Dominic Pajak, the BBC Micro Bot Twitter account accepts tweets and attempts to run them as BASIC programs on a BBC Microcomputer emulator, replying with the results of the program. It would seem that 280 characters would make it difficult to do anything interesting, but check out some of the results. Most are graphic displays, some animated, and with an unsurprising number of nods to 1980s pop culture. Some are truly impressive, though, like Conway’s Game of Life written by none other than Eben Upton.

The COVID-19 pandemic is causing all sorts of cultural shifts, but we didn’t expect to see much change in the culture of a community that’s been notoriously resistant to change for over a century: amateur radio. One of the most basic facts of life in the amateur radio world is that you need a license to participate, with governments regulating the process. But as a response to the pandemic, Spain has temporarily lifted licensing requirements for amateur radio operators. Normally, an unlicensed person is only allowed to operate on amateur bands under the direct supervision of a licensed amateur. The rules change allows unlicensed operators to use a station without supervision and is intended to give schoolchildren trapped at home an educational experience. In another change, some countries are allowing special callsign suffixes, like “STAYHOME,” to raise awareness during the pandemic. And the boom in interest in amateur radio since the pandemic started is remarkable; unfortunately, finding a way to take your test in a socially distant world is quite a trick. Our friend Josh Nass (KI6NAZ) has some thoughts about testing under these conditions that you might find interesting.

And finally, life goes on during all this societal disruption, and every new life deserves to be celebrated. And when Lauren Devinck made her appearance last month, her proud parents decided to send out unique birth announcement cards with a printed circuit board feature. The board is decorative, not functional, but adds a distinctive look to the card. The process of getting the boards printed was non-trivial; it turns out that free-form script won’t pass most design rule tests, and that panelizing them required making some compromises. We think the finished product is classy, but can’t help but think that a functional board would have really made a statement. Regardless, we welcome Lauren and congratulate her proud parents.

You’ll Really Want An “Undo” Button When You Accidentally Send A Ballistic Missile Warning

Hawaiians started their weekend with quite a fright, waking up Saturday morning to a ballistic missile alert that turned out to be a false alarm. In between the public anger, profuse apologies from officials, and geopolitical commentary, it might be hard to find some information for the more technical-minded. For this audience, The Atlantic has compiled a brief history of infrastructure behind emergency alerts.

As a system intended to announce life-critical information when seconds count, all information on the system is prepared ahead of time for immediate delivery. As a large hodgepodge linking together multiple government IT systems, there’s no surprise it is unwieldy to use. These two aspects collided Saturday morning: there was no prepared “Sorry, false alarm” retraction message so one had to be built from scratch using specialized equipment, uploaded across systems, and broadcast 38 minutes after the initial false alarm. In the context of government bureaucracy, that was really fast and must have required hacking through red tape behind the scenes.

However, a single person’s mistake causing such chaos and requiring that much time to correct is unacceptable. This episode has already prompted a lot of questions whose answers will hopefully improve the alert system for everyone’s benefit. At the very least, a retraction is now part of the list of prepared messages. But we’ve also attracted attention of malicious hackers to this system with obvious problems in design, in implementation, and also has access to emergency broadcast channels. The system needs to be fixed before any more chaotic false alarms – either accidental or malicious – erode its credibility.

We’ve covered both the cold-war era CONELRAD and the more recent Emergency Broadcast System. We’ve also seen Dallas’ tornado siren warning system hacked. They weren’t the first, they won’t be the last.

(Image: Test launch of an unarmed Minuteman III ICBM via US Air Force.)

Fixing POST Errors With A Single Key

one_key_keyboard

Instructables user [Mike Craghead] was in the middle of building a very compact public computer kiosk when he ran into a problem with the processor fan. It was too big for the enclosure and had to be swapped out with a fan that did not allow the motherboard to monitor its rotational speed.

Motherboards don’t like this situation very much, and each time the computer was started, it would hang at the BIOS screen waiting for someone to press the F1 key to continue. Knowing that everything was just fine, and that there were no BIOS options which would allow him to ignore the error, he crafted a simple solution to the problem.

Since the computer just needed someone to press the F1 key, he figured he could rig up a small dongle that would always hold down the key for him. After verifying that the OS would ignore the stuck key, he tore apart a keyboard and traced the circuit matrix to identify which pins he had to short in order to represent the F1 key press.

Satisfied with his handiwork, he plugged the board into his computer and found that everything worked just fine. Sure it might not be the most elegant solution to the problem, but it gets the job done at a cost of zero dollars – you can’t beat that!

Recover Acer Aspire One From “failed To Initialize HAL” Error

The Acer Aspire One is a netbook that often ships with a Linux OS preinstalled. This is great for fans of open source as market share is calculated based on units shipped, not what users install after they buy the hardware. Unfortunately there is a pretty major flaw that can cause a “failed to initialize HAL” error as seen above. [Michael Crummy] came up with a set of steps you can use to recover from this error.

So what is this error? HAL stands for Hardware Abstraction Layer and it’s what allows one user interface to communicate with many different types of hardware. If you’re the proud owner of an Aspire One and are struck with this error you will suddenly find that you can no longer use the USB ports, card readers, wired or wireless network connectors, or the sound card. So you can’t connect to the Internet, and you can’t get any files on or off of the device using the currently installed operating system. For an OS that [Neal Stephenson] once described as “like the M1 tanks of the U.S. Army, made of space-age materials and jammed with sophisticated technology” this is a very big problem.

We know what you’re thinking… boot into a live session on a thumb drive and get what you need from the hard disk. Well that’s all fine and dandy, but you shouldn’t ever be forced to clean install Linux to fix a problem. So check out [Michael’s] method and make sure you turn off the Acer live update server which was mostly likely the cause of the problem in the first place.

Fix 0LBA And BSY HDD Errors

One of the worst moments almost every hacker has experienced is a hard drive inexplicably dieing. And of course, its at the most inopportune time and you’ve had no chance to backup!

Recently there has been an influx of Seagate hard drives (specifically the 2700.11s) kicking the bucket with firmware errors 0LBA and BSY. The good news is [Gradius2] has made guides to unbrick your drive without having to match serials.

The procedure is lengthy, complicated, can easily become expensive, and there is the possibility of losing your data so it’s not recommended if you’re only getting those pictures of Mr.Fluffykins back. In such a case, Thermite might be a bit better solution.

[Thanks Calvin]