The 1970s Computer: A Slice Of Computing

March 6, 2024 by 46 Comments

What do the HP-1000 and the DEC VAX 11/730 have in common with the video games Tempest and Battlezone? More than you might think. All of those machines, along with many others from that time period, used AM2900-family bit slice CPUs.

The bit slice CPU was a very successful product that could only have existed in the 1970s. Today, if you need a computer system, there are many CPUs and even entire systems on a chip to choose from. You can also get many small board-level systems that would probably do anything you want. In the 1960s, you had no choices at all. You built circuit boards with gates on the using transistors, tubes, relays, or — maybe — small-scale IC gates. Then you wired the boards up.

It didn’t take a genius to realize that it would be great to offer people a CPU chip like you can get today. The problem is the semiconductor technology of the day wouldn’t allow it — at least, not with any significant amount of resources. For example, the Motorola MC14500B from 1977 was a one-bit microprocessor, and while that had its uses, it wasn’t for everyone or everything.

The Answer

The answer was to produce as much of a CPU as possible in a chip and make provisions to use multiple chips together to build the CPU. That’s exactly what AMD did with the AM2900 family. If you think about it, what is a CPU? Sure, there are variations, but at the core, there’s a place to store instructions, a place to store data, some way to pick instructions, and a way to operate on data (like an ALU — arithmetic logic unit). Instructions move data from one place to another and set the state of things like I/O devices, ALU operations, and the like.

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Thumbs Up To This Pico MIDI Kalimba

March 6, 2024 by 8 Comments

The kalimba, or thumb piano, is an easy way to make some music even if you have next to no idea what you’re doing. The only real downside is that they are limited to the twinkly sounds of metal tines being plucked by thumbs.

[Jeremy Cook] broke the sonic possibilities wide open by converting a couple of kalimbas into capacitive-touch MIDI instruments using the Raspberry Pi Pico. He started with a small one that is curiously made of solid wood. Usually these instruments are at least partially hollow to allow air to resonate inside the body.

After soldering up all the 1 MΩ resistors necessary to utilize the capacitive touch capabilities of the Pico, [Jeremy] found it a bit difficult to play individual notes on such a small instrument, so he made version two out of a much larger specimen.

This time, [Jeremy] cooked up a custom PCB which he is calling the Pico Touch 2, which adds the necessary resistors at the SMD level for capacitive touch sensing and in turn cleans up the wiring a bit. Be sure to check it out in action after the break.

Okay, so you don’t have an iota of musical talent. You could always build a kalimba that plays itself.

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Dial-Up Is Still, Just Barely, A Thing

March 6, 2024 by 95 Comments

In an era dominated by broadband and wireless cellular networks, it might come as a surprise to many that dial-up internet services still exist in the United States. This persistence is not a mere relic of nostalgia — but a testament to the diverse and uneven nature of internet infrastructure across the country.

Yes, dial-up internet, with those screechy, crackly tones, remains a useful tool in areas where modern, high-speed internet services are either unaffordable or unavailable. Subscriber numbers are tiny, but some plough on and access the Internet by the old ways, not the new.

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A bias tee module added inside the Starlink terminal, connected to the pads where a GPS antenna used to be wired

GPS Antenna Mods Make Starlink Terminal Immune To Jammers

March 6, 2024 by 70 Comments

The Starlink receivers need positioning and precise timing information to function, and currently the best way to get that information is to use a global navigation satellite system (GNSS) such as GPS. Unfortunately, the antenna used for this secondary satellite connection leaves something to be desired. Of course, when it comes to solving Starlink problems, there’s no one best than [Oleg Kutkov], whose duty is to fix and improve upon Starlink terminals used in Ukraine — and when the specific problem is GPS bands getting jammed by the invading military, you better believe that a fix is due.

[Oleg] sets the scene, walking us through the evolution of GPS circuitry on the Starlink terminals. Then he shows us the simplest mods you can do, like soldering an improved passive antenna in place of the chip antenna currently being used. Then, he takes it up a notch, and shows us how you could attach an active antenna by using a bias tee module, a mod that would surely work wonders on more than just this device! Then, he brings out the test result tables — and the differences are impressive, in that the Starlink terminals with active antenna mods were able to get GPS signal in areas with active jamming going on, while the unmodified ones could not.

The post is exceptionally accessible, and a must read for anyone wondering about GPS antenna reception problems in customer-accessible devices. This is not the only Starlink hardware mod we’ve seen [Oleg] make, we’ve just covered his Starlink Ethernet port restoration journey that meticulously fixes Ethernet connectivity oversights in the newer models, and the blog also has an article about powering Starlink terminals without the need for PoE, so, do check it out if you’re looking for more!

Automated System Keeps Camper Van Air Fresh And Warm

March 6, 2024 by 22 Comments

Air quality has become a hot topic in recent years. [Ryan Stout] was interested in improving it in his camper van, and set about doing something about it. His solution was an automated system that provided cleaner air and better comfort to boot.

The concept was simple. [Ryan]’s system is based on an Arduino clone, and uses a SparkFun SCD40 as a CO2 sensor, and an MCP9808 for temperature. When the system detects excess carbon dioxide levels, it opens the MaxxAir fan in the camper by triggering it with an infrared signal. Similarly, when it detects excessively low temperatures inside the van, it kicks on a diesel furnace for heating. In a neat addition, to avoid the fan sucking in exhaust fumes, it also closes the fan in order to avoid exhaust fumes entering the camper unnecessarily. All the hardware was then  wrapped up in a simple 3D printed enclosure.

With this setup, [Ryan] has managed to cut the buildup of CO2 in his camper at night, and he credits this with reducing morning headaches when he’s out in the camper. We’d call that a win, to say nothing of the additional comfort created by the automatically-controlled heater! If you’re interested in something similar for your home HVAC system, we’ve got you covered.

Yuzu And Citra Emulators Shut Down After Legal Pressure From Nintendo

March 5, 2024 by 40 Comments

In a move that came rather like a surprise to many, the company behind the well-known Switch and 3DS emulators Yuzu and Citra – Tropic Haze LLC – as reported by PC Gamer has shutdown both projects and associated websites as part of a US$2.4M settlement with Nintendo with a last message left on the Yuzu website. This comes in the wake of Nintendo suing Tropic Haze LLC over the Yuzu emulator, claiming that there’s ‘no lawful way to use Yuzu’, as it requires files extracted from a real Switch device to decrypt game files. Although Citra is not part of the lawsuit, it being made by the same developers seems to have resulted in it getting axed along with Yuzu as collateral damage.

What makes this issue so legally hairy is that even though an emulator by itself isn’t illegal, requiring proprietary firmware and keys already gets one into contested territory about the legality of dumping said files from a console, even if you own it. This was already an issue with the first Playstation emulators, which require the Playstation BIOS image to even boot, but left the emulator developers mostly untouchable. What seems to have set off Nintendo’s lawyers here would seem to be the way that the Yuzu developers leaned into the copyright infringement (often incorrectly called ‘piracy’) angle, giving Nintendo’s legal team enough exposed flesh to launch a ballistic legal strike.

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Large Language Model Can Help You Develop For The Amiga

March 5, 2024 by 13 Comments

Developing for the Amiga used to involve reading dense programming manuals and trial and error. In contrast, developing these days can be as simple as barking orders at ChatGPT to spit you out some Python code. However, that technique doesn’t work so well for Amiga languages, as ChatGPT hasn’t read much about the now-ancient platform. However, as covered by AmigaNews, there is now a ChatGPT model trained specifically on Amiga development. Enter Amiga Guru.

The work of [Cameron Armstrong], Amiga Guru was built after his early experiments with ChatGPT spat out non-functional gibberish when Amiga-compatible code was requested. The model has been trained on a corpus of official Amiga programming manuals, third-party books, and even the documentation for AmigaOS 3.2 and 4.1.

Using the model yourself requires a subscription to ChatGPT Plus, which prevents this writer from testing it directly. However, it makes sense that having been directly trained on Amiga manuals, it would be more capable at answering Amiga programming queries than conventional ChatGPT 4.

It’s easy to see the value of such a system. Learning to program for older platforms can be hard, with less resources available for new learners. Having an AI to help could be useful for some eager to develop for the 68K-based machine.

If you’d like to try Amiga Guru, you can access it via this link. Be sure to let us know how you go, and whether you think it has any value for speeding up your own Amiga development. Otherwise, if you’ve been doing anything else nifty with the platform that Commodore bought and paid for, don’t hesitate to let us know!

[Thanks to Stephen Waters for the tip!]