computer hacks

1313 Articles

computer hacks

DIY VT220 Keyboard

August 8, 2017 by 17 Comments

There’s always been interest in the computers of old, and people love collecting and restoring them. When [peterbjornx] got his hands on a DEC VT220 video terminal, it was in good shape – it needed a bit of cleaning, but it also needed a keyboard. [Peter] couldn’t afford to buy the keyboard, but the service manual for it was available, so he decided to convert a modern keyboard to work with his new terminal. (Editor’s note: Link rot. Try the Internet Archive’s Wayback Machine link instead.)

The original keyboard for the VT220 is the LK201. This keyboard communicates with the terminal using 8-N-1 (eight data bits, no parity, one stop bit) over RS232 at 4800 baud. This meant that it would be pretty simple to implement this on microcontroller in order to communicate with the terminal. [Peter] chose the Arduino Nano. However, the LK200 was more than just a keyboard for communicating with the terminal, it also housed a speaker and LEDs which the terminal used to communicate with the user. Rather than put these into the adapter unit, [Peter] decided to put these into the keyboard – a few holes and a bit of wiring, and they were in.

[Peter]’s write-up includes a description of some of the issues he encountered as well as a picture of the keyboard. He’s put the schematic online and the code up on GitHub. In case you were wondering, he used Vim on the VT220 to write his article. You could also use a Raspberry Pi to help out your dumb terminal, or just hook the terminal directly to your Linux box and go from there.

Starter Guide To Linux Forensics

August 8, 2017 by 11 Comments

The old saying is if your data isn’t backed up at least twice, it’s not backed up at all. For those not wise enough to heed this adage, there are a number of options available to you if you wish your data to be recovered. Assuming the drive itself is just corrupted somehow (maybe a malicious attack, maybe a user error) and not damaged beyond physical repair, the first step is to connect the drive to another computer. If that fails, it might be time to break out the computer forensics skills.

[Luis]’s guide is focused on Linux-specific drives and recovery tools, so this isn’t necessarily a general-purpose how-to. That being said, there is a lot of information in this guide such as how to mount the target drive’s partitions, how to set up various timelines, and which of the Linux system’s logs are important for the forensic analysis. This specific example in the guide also goes into detail about noticing which of the recent files had been accessed, what they might have done, and different approaches to piecing the mystery of this corrupted drive together.

[Luis] points out that the world of Linux forensics is much different from that of Windows, but for anyone looking to get started he suggests starting with a clean Linux install and going from there. There are many other avenues of digital forensics, as well; the field has as many avenues of exploration as there are different types of computers.

MagSafe Power Bank From Scrap

August 4, 2017 by 23 Comments

Just a few short years ago, it was possible to find scrapped lithium batteries for free, or at least for very cheap. What most people at the time didn’t realize is that a battery with multiple cells might go bad because only one cell is bad, leaving the others ready for salvaging. Now it’s not a secret anymore, but if you can manage to get your hands on some there’s a lot of options for use. [ijsf] took a step further with this hack, taking a few cells from a Panasonic battery and wrangling them into a MagSafe-capable power bank for a Mac.

The real hack wasn’t scavenging batteries, however, it was getting the MagSafe to signal the computer to use power from the battery bank to run the computer only, and not to use any of that energy for charging the computer’s internal batteries. This is achieved by disabling the center MagSafe pin, which is the computer’s communication line to the power adapter. After that, the battery bank could be programmed to behave properly (a feat in itself for lithium batteries) and the power bank was successfully put into operation.

Not only was this hack a great guide for how to repurpose cells from a “dead” battery, it’s also an unparalleled quick reference for any work that might need a MagSafe connector. Of course, if you’re going to work with these chargers, make sure that you’re using one that isn’t a cheap clone.

Under The Hood Of AMD’s Threadripper

August 3, 2017 by 52 Comments

Although AMD has been losing market share to Intel over the past decade, they’ve recently started to pick up steam again in the great battle for desktop processor superiority. A large part of this surge comes in the high-end, multi-core processor arena, where it seems like AMD’s threadripper is clearly superior to Intel’s competition. Thanks to overclocking expert [der8auer] we can finally see what’s going on inside of this huge chunk of silicon.

The elephant in the room is the number of dies on this chip. It has a massive footprint to accommodate all four dies, each with eight cores. However, it seems as though two of the cores are deactivated due to a combination of manufacturing processes and thermal issues. This isn’t necessarily a bad thing, either, or a reason not to use this processor if you need to utilize a huge number of cores, though; it seems as though AMD found it could use existing manufacturing techniques to save on the cost of production, while still making a competitive product.

Additionally, a larger die size than required opens the door for potentially activating the two currently disabled chips in the future. This could be the thing that brings AMD back into competition with Intel, although both companies still maintain the horrible practice of crippling their chips’ security from the start.

A Chrome Extension For Being A Jerk

August 3, 2017 by 12 Comments

What do you do to someone you want to make suffer, slowly? Specifically, at around 70% speed. To [Stephen], the answer is clear, you hit them where it really hurts: YouTube.

Creatively named “Chrome Engine,” [Stephen]’s diabolical Chrome extension has one purpose: be annoying. Every day, it lowers playback rate by 1% on YouTube. It’s a linear progression: 100% the first day, 99% the second day, 98% the third day, etc. It only stops 30 days later, once it hits its target rate of 70% the original speed. This progression is designed to be slow enough not to be noticed. Its icon is nothing more than the standard Chrome icon as [Stephen] firmly believes in the tactic of hiding in plain sight.

But that’s not all, it’s the minute details that drive the ball home. For instance, rather than using local storage to keep track of playback speed, the Chrome sync storage is used. This ensures that, as long as the extension is installed, playback rate will be synchronized between all of your friend’s(if you can even call them that) devices. It even targets casual YouTube users: [Stephen] has specifically designed their extension so that it won’t drop playback by more than 1% at a time. If the victim goes on vacation, the playback speed won’t drop when they’re away and will resume as soon as they’re back.

The last feature, the one [Stephen] is the proudest of, is that the extension manages to keep the YouTube speed controls working as intended. If the victim tries to play at half speed, their videos will be at half speed … of the slower playback rate set by the extension. And it gets even better! You may not know this if you don’t dally around with playback rates, but the audio tends to stop playing when videos are reduced below 50% of their original speed. Fear not! [Stephen] has accounted for this idiosyncrasy! If the victim selects a speed at or above 0.5x, a minimum cap is added so that the actual playback rate will be equal to or above 0.5x. If they select slower than this, they don’t expect sound anyway, so all bets are off.

Check it out here, may your friends (frenemies?) beware. We’re adding it to our April Fools arsenal, even if it is a bit early.

A Wii U That Is Both Computer And Console.

August 2, 2017 by 16 Comments

Legendary sudomod forum user [banjokazooie] has once again demonstrated their prowess in Wii U console modification — this time by transforming it into a powerhouse portable computer!

We loved [banjokazooie]’s RetroPie Wii U mod, and happy to see them back again with this build.  What’s in this thing this time around? Buckle up ’cause it’s a ride: an Intel M5 processor core M on their Compute Stick, 4GBs RAM, a 64GB solid-state drive, a 2K LCD touchscreen, Bluetooth, WiFi, a 128GB SD card slot, two 3.7V 4000 mAh batteries, a Pololu 5V,6A step-down voltage regulator, a Teensy 2.0++ dev board, a battery protection PCB, a USB DAC sound card, stereo amp, a USB hub for everything to plug into, and a TP5100 battery charging board. Check it out!

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KIM-1 To COSMAC Elf Conversion — Sort Of

July 25, 2017 by 11 Comments

In the mid-1970s, if you had your own computer, you probably built it. If you had a lot of money and considerable building skill, you could make an Altair 8800 for about $395 — better than the $650 to have it built. However, cheaper alternatives were not far behind.

In 1976, Popular Electronics published plans for a computer called the COSMAC Elf which you could build for under $100, and much less if you had a good junk box. The design was simple enough that you could build it on a piece of perf board or using wire wrap. We featured the online archive of the entire Popular Electronics collection, but hit up page 33 of this PDF if you want to jump right to the article that started it all. The COSMAC Elf is a great little machine built around a 40-pin RCA 1802 processor, and for many was the first computer they owned. I lost my original 1802 computer in a storm and my recent rebuild in another completely different kind of storm. But there is a way to reclaim those glory days without starting from scratch.  I’m going to repurpose another retro-computing recreation; the KIM-1.

I’ll admit it, Rewiring a real KIM-1 to take an 1802 CPU would be difficult and unnecessary and that’s not what this article is about. However, I did have a KIM UNO — [Oscar’s] respin of the classic computer using an Arduino mini pro. Looking at the keyboard, it occurred to me that the Arduino could just as easily simulate an 1802 as it could a 6502. Heck, that’s only two digits different, right?

The result is pretty pleasing. A “real” Elf had 8 toggle switches, but there were several variations that did have keypads, so it isn’t that far off. Most Elf computers had 256 bytes of memory (without an upgrade) but the 1802 UNO (as I’m calling it) has 1K. There’s also a host of other features, including a ROM and a monitor for loading and debugging programs that doesn’t require any space in the emulated 1802.

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