A New Commodore C128 Cartridge

April 17, 2023 by 18 Comments

A new Commodore C128 cartridge in 2023?  That’s what [idun-projects] set out to do and, as you can see in the video below, did. I did the original C128 hardware design and worked with the amazing team that turned this home computer out in 1985. Honestly, I am amazed that any of them are still working 38 years later, let alone that someone is making new cartridges for it.

I also never thought I would hear about someone’s in-depth experience designing for the ‘128. The post takes us through [idun-project’s] decision to use the ‘128 and how modern expectations apply to all computers, even the old ones. Hot on the list was connectivity and reasonable storage (looking at you, floppy disks).

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Robot Races A Little Smarter To Go Faster

April 17, 2023 by 4 Comments

[Steven Gong] is attending the University of Waterloo and found himself with a 1/10th scale F1TENTH autonomous RC car. What better use of a fast RC car with some smarts than to race itself around your computer science building?

Onboard is an Nvidia Jetson NX (not the new Nvidia Jetson Orin), a lidar module, and a depth camera. The code runs on top of ROS2, and the results were impressive. [Steven] mapped out the fifth floor of his building at 6 am using SLAM and the onboard sensors. With a map, he created a rough track for his car to follow. First, the car needs to know when to brake and when to hit the gas. With the basics out of the way, [Steven] moved on to the fun part. He wrote code to generate a faster racing line. Every turn has an optimal speed and approach, but each turn affects the next turn, which turns it into a rather exciting optimization problem.

Along the way, [Steven] fixed the gearbox, tuned the PID steering loop, and removed the software speed limits. It’s impressive engineering, and we love seeing the car zoom around faster and faster. The car eventually hit 25km/h, which seems pretty fast for indoors. The code and more details are up on GitHub.

However, if you’re curious about playing around with self-driving, perhaps a much smaller scale Pi Zero-based racer might be more your speed. Video after the break.

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New Renewable Energy Projects Are Overwhelming US Grids

April 17, 2023 by 239 Comments

It’s been clear for a long time that the world has to move away from fossil energy sources. Decades ago, this seemed impractical, when renewable energy was hugely expensive, and we were yet to see much impact on the ground from climate change. Meanwhile, prices for solar and wind installations have come down immensely, which helps a lot.

However, there’s a new problem. Power grids across the US simply can’t keep up with the rapid pace of new renewable installations. It’s a frustrating issue, but not an insurmountable one.

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Wolfram Alpha With ChatGPT Looks Like A Killer Combo

April 17, 2023 by 31 Comments

Ever looked at Wolfram Alpha and the development of Wolfram Language and thought that perhaps Stephen Wolfram was a bit ahead of his time? Well, maybe the times have finally caught up because Wolfram plus ChatGPT looks like an amazing combo. That link goes to a long blog post from Stephen Wolfram that showcases exactly how and why the two make such a wonderful match, with loads of examples. (If you’d prefer a video discussion, one is embedded below the page break.)

OpenAI’s ChatGPT is a large language model (LLM) neural network, or more conventionally, an AI system capable of conversing in natural language. Thanks to a recently announced plugin system, ChatGPT can now interact with remote APIs and therefore use external resources.

ChatGPT’s natural language processing ability enables some pretty impressive interactions with Wolfram, enabling the kind of exchange you see here (click to enlarge.)

This is meaningful because LLMs are very good at processing natural language and generating plausible-sounding output, but whether or not the output is factually correct can be another matter. It’s not so much that ChatGPT is especially prone to confabulation, it’s more that the nature of an LLM neural network makes it difficult to ask “why exactly did you come up with your answer, and not something else?” In addition, asking ChatGPT to do things like perform nontrivial calculations is a bit of a square peg and round hole situation.

So how does the Wolfram plugin change that? When asked to produce data or perform computations, ChatGPT can now hand it off to Wolfram Alpha instead of attempting to generate the answer by itself.  Both sides use their strengths in this arrangement. First, ChatGPT interprets the user’s question and formulates it as a query, which is then sent to Wolfram Alpha for computation, and ChatGPT structures its response based on what it got back. In short, ChatGPT can now ask for help to get data or perform a computation, and it can show the receipts when it does.

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PUF Away For Hardware Fingerprinting

April 17, 2023 by 9 Comments

Despite the rigorous process controls for factories, anyone who has worked on hardware can tell you that parts may look identical but are not the same. Everything from silicon defects to microscopic variations in materials can cause profoundly head-scratching effects. Perhaps one particular unit heats up faster or locks up when executing a specific sequence of instructions and we throw our hands up, saying it’s just a fact of life. But what if instead of rejecting differences that fall outside a narrow range, we could exploit those tiny differences?

This is where physically unclonable functions (PUF) come in. A PUF is a bit of hardware that returns a value given an input, but each bit of hardware has different results despite being the same design. This often relies on silicon microstructure imperfections. Even physically uncapping the device and inspecting it, it would be incredibly difficult to reproduce the same imperfections exactly. PUFs should be like the ideal version of a fingerprint: unique and unforgeable.

Because they depend on manufacturing artifacts, there is a certain unpredictability, and deciding just what features to look at is crucial. The PUF needs to be deterministic and produce the same value for a given specific input. This means that temperature, age, power supply fluctuations, and radiation all cause variations and need to be hardened against. Several techniques such as voting, error correction, or fuzzy extraction are used but each comes with trade-offs regarding power and space requirements. Many of the fluctuations such as aging and temperature are linear or well-understood and can be easily compensated for.

Broadly speaking, there are two types of PUFs: weak and strong. Weak offers only a few responses and are focused on key generation. The key is then fed into more traditional cryptography, which means it needs to produce exactly the same output every time. Strong PUFs have exponential Challenge-Response Pairs and are used for authenticating. While strong PUFs still have some error-correcting they might be queried fifty times and it has to pass at least 95% of the queries to be considered authenticated, allowing for some error. Continue reading “PUF Away For Hardware Fingerprinting” →

A Clock Timebase, No Microcontroller

April 17, 2023 by 20 Comments

Making an electronic clock is pretty easy here in 2023, with a microcontroller capable of delivering as many quartz-disciplined pulses as you’d like available for pennies. But how did engineers generate a timebase back in the old days, and how would you do it today? It’s a question [bicyclesonthemoon] is answering, with a driver for a former railway station clock.

The clock has a mechanism that expects pulses every minute, a +24V pulse on even minutes, and a -24V pulse on odd ones. He received a driver module with it, but for his own reasons wanted a controller without a microcontroller. He also wanted the timebase to be derived from the mains frequency. The result is a delve back into 1970s technology, and the type of project that’s now a pretty rare sight. Using a mixture of 4000 series logic and a few of the ubiquitous 555s [bicyclesonthemoon] recovers 50Hz pulses from the AC, and divides them down to 1 pulse per minute, before splitting into odd and even minutes to drive a pair of relays which in turn drive the clock. We like it, a lot.

Mains-locked clocks are less common than they used to be, but they’re still a thing. Do you still wake up to one?

Interlaken Want To Connect All The Chips

April 17, 2023 by 11 Comments

One of the problems with designing things on a chip is finding a good way to talk to the outside world. You may not design chips yourself, but you care because you want to connect your circuits — including other chips — to the chips in question. While I2C and SPI are common solutions, today’s circuits are looking for more bandwidth and higher speeds, and that’s where Interlaken comes in. [Comcores] has an interesting post on the technology that blends the best of SPI 4.2 and XAUI.

The interface is serial, as you might expect. It can provide both high-bandwidth and low-latency multi-channel communications. Interlaken was developed by Cisco and Cortina Systems in 2006 and has since been adopted by other industry-leading companies. Its latest generation supports speeds as high as 1.2 Tbps.

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