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.
Technology is designed to serve us and make our lives better. When a device gets outdated, it is either disposed of or is buried in a pile of junk never to be seen again. However, some individuals tend to develop a certain respect for their mechanical servants and make an effort to preserve them long after they have become redundant.
My relationship with my first laptop is a shining example of how to hold onto beloved hardware way too long. I converted that laptop into a desktop with a number of serious modifications which helped me learn about woodworking along the way. Maybe it’s more pragmatic to just buy new equipment. But you spend so much time each day using your devices. It is incredibly satisfying to have a personal connection that comes from pouring your own craftsmanship into them.
Why the Effort?
The laptop in question is an IBM R60 which I lugged around during the first three years after I graduated. It was my companion during some tough times and naturally, I developed a certain attachment to it. With time its peripherals failed including the keyboard which housed the power switch and it was decided that the cost of repair would outweigh its usefulness.
Then came the faithful day when I was inspired to make something with the scrap wood that had accumulated in my workshop. This would be my second woodworking project ever and I did not have the professional heavy machinery advertised in most YouTube videos. Yet I had two targets in mind with this project.
Make the R60 useful again.
Learn about woodworking for creating enclosures for future projects.
Armed with mostly hand tools, a drill and a grinder that was fitted with a saw blade, I started with the IBM R60 to all-in-one PC mod. Following is a log of things I did and those I regret not doing a.k.a. lessons learned. Read on.
Sometimes it starts with a 555 timer and an op-amp. Other times with a small microcontroller. But the timing’s not so great and needs a dedicated timing crystal circuit. And maybe some more memory, and maybe the ATtiny should be swapped out for some 74LS-series chips. And now of course it needs video output too. Before you know it, you’re staring at a 40-chip computer that hearkens back to a simpler, yet somehow more complex, time of computing. At least that’s where [Marcel] is with his breadboard computer based on 1970s-era chips.
For what it does, this homebrew computer is relatively simple and straightforward. It gets 8 bits of processing power from 34 TTL chips. Another 6 round out the other features needed for the computer to operate. It is capable of rendering 64 colors in software and has more than enough memory for a computer of this sort. So far the only recurring problem [Marcel] has had has been with breadboard fatigue, as some of the chips keep popping out of the sockets.
This is a great project for anyone interested in homebrew or 8-bit computing, partially because of some of the self-imposed limitations that [Marcel] imposed on himself, like “only chips from the 70s”. It’s an impressive build on its own and looks to get much better since future plans call for a dedicated PCB to solve the issue with the worn-out breadboards. If you’re already invested in a project like this, don’t forget that the rabbit hole can go a little deeper: you can build a computer out of discrete transistors as well.
[Jack Eisenmann] is no stranger to building impressive DIY CPU’s on vast stretches of breadboard. This time [Jack] has done away with the seventeen breadboards he used in his last 8-bit computer and instead has gone a step further and designed a set of generously utilised PCB’s for the CPU. The result is the DUO Enterprise.
The CPU design is based around an 8-bit data bus and a 24-bit address bus. As usual, a minimal yet carefully chosen instruction set allows [Jack] to do all the heavy lifting in software as part of the compiler and operating system he is working on. There is no sign of a display yet, instead the computer communicates via a dumb terminal. We love the aluminum foil for shielding! Check out the video, below, to see what we mean.
You can store arbitrary data encoded in binary as a pattern of zeros and ones. What you do to get those zeros and ones is up to you. If you’re in a particularly strange mood, you could even store them as strips of chocolate on Swedish pancakes.
Oddly enough, the possibility of the pancake as digital storage medium was what originally prompted [Michael Kohn] to undertake his similar 2013 project where he encoded his name on a paper wheel. Perhaps wisely, he prototyped on a simpler medium. With that perfected, four years later, it was time to step up to Modified Swedish Pancake Technology (MSPT).
Highlights of the build include trying to optimize the brightness difference between chocolate and pancake. Reducing the amount of sugar in the recipe helps increase contrast by reducing caramelization, naturally. And cotton balls placed under the spinning cardboard platform can help stabilize the spinning breakfast / storage product.
Even so, [Michael] reports that it took multiple tries to get the sixteen bytes (bites?) of success in the video below. The data is stenciled onto the pancake and to our eye is quite distinct. Improvement seems to be more of an issue with better edge detection for the reflectance sensor.
The aptly named [Clickity Clack]’s new YouTube channel promises to be very interesting if he can actually pull off a working computer using nothing but relays. But even if he doesn’t get beyond the three videos in the playlist already, the channel is definitely worth checking out. We’ve never seen a simpler, clearer explanation of binary logic, and [Clickity Clack]’s relay version of the basic logic gates is a great introduction to the concepts.
Using custom PCBs hosting banks of DPDT relays, he progresses from the basic AND and XOR gates to half adders and full adders, explaining how carry in and carry out works. Everything is modular, so four of his 4-bit adder cards eventually get together to form a 16-bit adder, which we assume will be used to build out a very noisy yet entertaining ALU. We’re looking forward to that and relay implementations of the flip-flops and other elements he’ll need for a full computer.
Every December and May the senior design projects from engineering schools start to roll in. Since the students aren’t yet encumbered with real-world detractors (like management) the projects are often exceptional, unique, and solve problems we never even thought we had. Such is the case with [Mark] and [Peter]’s senior design project: a pick and place machine that promises to solve all of life’s problems.
Of course we’ve seen pick-and-place machines before, but this one is different. Rather than identifying resistors and capacitors to set on a PCB, this machine is able to identify and sort candies. The robot — a version of the MeARM — has three degrees of freedom and a computer vision system to alert the arm as to what it’s picking up and where it should place it. A Raspberry Pi handles the computer vision and feeds data to a PIC32 which interfaces with the hardware.
One of the requirements for the senior design class was to keep the budget under $100, which they were able to accomplish using pre-built solutions wherever possible. Robot arms with dependable precision can’t even come close to that price restraint. But this project overcomes the lack of precision in the MeArm by using incremental correcting steps to reach proper alignment. This is covered in the video demo below.
Senior design classes are a great way to teach students how to integrate all of their knowledge into a final class, and the professors often include limits they might find in the real world (like the budget limit in this project). The requirement to thoroughly document the build process is also a lesson that more people could stand to learn. Senior design classes have attempted to solve a lot of life’s other problems, too; from autonomous vehicles to bartenders, there’s been a solution for almost every problem.