Copying Commodore Data Tapes, 40 Years Late

February 28, 2025 by Bryan Cockfield 40 Comments

Unless you handle the backups for a large corporation, bank, or government entity, you likely haven’t stored much data to tape recently. But magnetic storage used to be fairly mainstream back in the 1980s for all kinds of computer programs. Plenty of computers used standard cassette tapes for this too but you couldn’t just copy them with standard audio equipment. You’d need something like this 1560 datasette from [Jan].

The core problem with using Hi-Fi equipment to copy tapes storing data instead of audio is that data tapes need to be much more precise in order to avoid losses that might not be noticeable in an audio recording. In the 80s computer companies like Commodore built tape drives specifically for their computers, so [Jan]’s project uses two of these 1530 drives to build this “1560” datasette. (No working 1530 hardware was harmed in this build.) An inverter circuit in one tape deck is used to provide the signal to write the data to the other tape, reliably copying data from these data tapes in a way Hi-Fi never could.

[Jan] does lament not having something like this back in the 80s when the Commodore was in its heyday, but there’s still a dedicated retrocomputing scene for these machines that will get plenty of use out of projects like this. If you need to go the other direction in time, there are also interfaces that allow data tapes from old Commodores to be read by modern computers with USB.

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Shelved Kindle Gets New Life As Weather Display

February 27, 2025 by Bryan Cockfield 8 Comments

In the rush to always have the latest and greatest, it’s not uncommon that perfectly serviceable hardware ends up collecting dust in a drawer somewhere. If you’ve got an old Kindle laying around, you may be interested in this write-up from [Hemant] that shows a practical example of how the popular e-reader can be pushed into service as a weather dashboard.

The first step is to jailbreak the Kindle, providing the user with root access to the device. From there the Kindle Unified Application Launcher (KUAL) is installed along with USBNetwork which allows you to connect to the reader over SSH. With root access and a network connection, the real project of converting it to a weather dashboard begins. [Hemant] split the project into two parts here, a Node.js server that scrapes weather data from the internet and converts it into an image, and a client for the Kindle that receives this image for display.

The Kindle has a number of quirks and issues that [Hemant] covers as well, including handling image ghosting on the e-ink display as well as a problem where the device will hang if the Internet connection is lost. For those with jailbroken Kindles that want to put their devices back into useful service, this is an excellent guide for getting started and [Hemant] also provided all of the source code on the project’s GitHub page.

There has been a long tradition of using Kindles for things other than e-readers, and even devices with major hardware problems can still have useful life in them thanks to this project which allows the e-ink display to have a second life on its own.

Import GPU: Python Programming With CUDA

February 25, 2025 by Bryan Cockfield 17 Comments

Every few years or so, a development in computing results in a sea change and a need for specialized workers to take advantage of the new technology. Whether that’s COBOL in the 60s and 70s, HTML in the 90s, or SQL in the past decade or so, there’s always something new to learn in the computing world. The introduction of graphics processing units (GPUs) for general-purpose computing is perhaps the most important recent development for computing, and if you want to develop some new Python skills to take advantage of the modern technology take a look at this introduction to CUDA which allows developers to use Nvidia GPUs for general-purpose computing.

Of course CUDA is a proprietary platform and requires one of Nvidia’s supported graphics cards to run, but assuming that barrier to entry is met it’s not too much more effort to use it for non-graphics tasks. The guide takes a closer look at the open-source library PyTorch which allows a Python developer to quickly get up-to-speed with the features of CUDA that make it so appealing to researchers and developers in artificial intelligence, machine learning, big data, and other frontiers in computer science. The guide describes how threads are created, how they travel along within the GPU and work together with other threads, how memory can be managed both on the CPU and GPU, creating CUDA kernels, and managing everything else involved largely through the lens of Python.

Getting started with something like this is almost a requirement to stay relevant in the fast-paced realm of computer science, as machine learning has taken center stage with almost everything related to computers these days. It’s worth noting that strictly speaking, an Nvidia GPU is not required for GPU programming like this; AMD has a GPU computing platform called ROCm but despite it being open-source is still behind Nvidia in adoption rates and arguably in performance as well. Some other learning tools for GPU programming we’ve seen in the past include this puzzle-based tool which illustrates some of the specific problems GPUs excel at.

Genetic Algorithm Runs On Atari 800 XL

February 21, 2025 by Bryan Cockfield 7 Comments

For the last few years or so, the story in the artificial intelligence that was accepted without question was that all of the big names in the field needed more compute, more resources, more energy, and more money to build better models. But simply throwing money and GPUs at these companies without question led to them getting complacent, and ripe to be upset by an underdog with fractions of the computing resources and funding. Perhaps that should have been more obvious from the start, since people have been building various machine learning algorithms on extremely limited computing platforms like this one built on the Atari 800 XL.

Unlike other models that use memory-intensive applications like gradient descent to train their neural networks, [Jean Michel Sellier] is using a genetic algorithm to work within the confines of the platform. Genetic algorithms evaluate potential solutions by evolving them over many generations and keeping the ones which work best each time. The changes made to the surviving generations before they are put through the next evolution can be made in many ways, but for a limited system like this a quick approach is to make small random changes. [Jean]’s program, written in BASIC, performs 32 generations of evolution to predict the points that will lie on a simple mathematical function.

While it is true that the BASIC program relies on stochastic methods to train, it does work and proves that it’s effective to create certain machine learning models using limited hardware, in this case an 8-bit Atari running BASIC. In previous projects he’s also been able to show how similar computers can be used for other complex mathematical tasks as well. Of course it’s true that an 8-bit machine like this won’t challenge OpenAI or Anthropic anytime soon, but looking for more efficient ways of running complex computation operations is always a more challenging and rewarding problem to solve than buying more computing resources.

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Open-Source Random Numbers

February 20, 2025 by Bryan Cockfield 25 Comments

Whether it’s a game of D&D or encrypting top-secret information, a wide array of methods are available for generating the needed random numbers with high enough entropy for their use case. For a tabletop game this might be a single die but for more sensitive applications a more robust method of generating random numbers is needed. Programmers might reach for a rand() function of some sort, but these pseudorandom numbers don’t cut the mustard for encryption. For that you’ll need a true random number generator (RNG), and this open-source hardware RNG uses one of the better methods we’ve seen.

The device, called RAVA, is based on a property found in many electronic devices called avalanche breakdown. Avalanche breakdown occurs when a high voltage (in this case approximately 25V) is applied in the reverse bias direction, with this device using a pair of Zener diodes. When this high voltage is applied, an “avalanche” of electrons occurs which allows the diodes conduct in the opposite direction that they would when they are forward biased. This isn’t a constant current flow, though; there are slight variations over time which can be amplified and used as the random number generator. The noise is amplified over a series of op amps and then fed to an ATmega32U4 microcontroller which can provide the user with 136.0 Kbit/s of random data.

Unlike other random number generators, this device is based on a method generally accepted to be truly random. Not only that, but since it’s based on discrete hardware it can be accessed directly for monitoring and replacement in case of faults, unlike other methods which are more “black boxes” and are more opaque in their processes which are thus harder to audit. We also appreciate it’s open-source nature as well, and for some more information on it be sure to check out the paper on it in IEEE. If you’re looking for something to generate random numbers but will also bring some extra flair to the next game night, take a look at this radioactive dice replacement.

Measuring Local Variances In Earth’s Magnetic Field

February 17, 2025 by Bryan Cockfield 11 Comments

Although the Earth’s magnetic field is reliable enough for navigation and is also essential for blocking harmful solar emissions and for improving radio communications, it’s not a uniform strength everywhere on the planet. Much like how inconsistencies in the density of the materials of the planet can impact the local gravitational force ever so slightly, so to can slight changes impact the strength of the magnetic field from place to place. And it doesn’t take too much to measure this impact on your own, as [efeyenice983] demonstrates here.

To measure this local field strength, the first item needed is a working compass. With the compass aligned to north, a magnet is placed with its poles aligned at a right angle to the compass. The deflection angle of the needle is noted for varying distances of the magnet, and with some quick math the local field strength of the Earth’s magnetic field can be calculated based on the strength of the magnet and the amount of change of the compass needle when under its influence.

Using this method, [efeyenice983] found that the Earth’s magnetic field strength at their location was about 0.49 Gauss, which is well within 0.25 to 0.65 Gauss that is typically found on the planet’s surface. Not only does the magnetic field strength vary with location, it’s been generally decreasing in strength on average over the past century or so as well, and the poles themselves aren’t stationary either. Check out this article which shows just how much the poles have shifted over the last few decades.

Decoy Killswitch Triggers Alarm Instead

February 17, 2025 by Bryan Cockfield 43 Comments

There are a few vehicles on the road that are targeted often by car thieves, whether that’s because they have valuable parts, the OEM security is easily bypassed, or even because it’s an antique vehicle that needs little more than a screwdriver to get started. For those driving one of these vehicles an additional immobilization feature is often added, like a hidden switch to deactivate the fuel pump. But, in the continual arms race between thieves and car owners, this strategy is easily bypassed. [Drive Science] hopefully took one step ahead though and added a decoy killswitch instead which triggers the alarm.

The decoy switch is placed near the steering column, where it would easily be noticed by a thief. Presumably, they would think that this was the reason the car wouldn’t start and attempt to flip the switch and then start the ignition. But secretly, the switch activates a hidden relay connected to the alarm system, so after a few seconds of the decoy switch activating, the alarm will go off regardless of the position of this switch. This build requires a lot of hiding spots to be effective, so a hidden method to deactivate the alarm is also included which resets the relay, and another killswitch which actually disables the fuel pump is also added to another secret location in the car.

As far as “security through obscurity” goes, a build like this goes a long way to demonstrate how this is an effective method in certain situations. All that’s generally needed for effective car theft prevention is to make your car slightly more annoying to steal than any other car on the road, and we think that [Drive Science] has accomplished that goal quite well. Security through obscurity is generally easily broken on things deployed on a much larger scale. A major European radio system was found to have several vulnerabilities recently thanks in part to the designers hoping no one would look to closely at them.

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