c64

92 Articles

C64 Turned Theremin With A Handful Of Parts

August 30, 2022 by 7 Comments

The theremin is popular for its eerie sound output and its non-contact playing style. While they’re typically built using analog hardware, [Linus Åkesson] decided to make one using the venerable Commodore 64.

The instrument works by measuring the capacitance between its two antennas and the Earth. As these capacitances are changed by a human waving their hands around near the respective pitch and volume antennas, the theremin responds by changing the pitch and volume of its output.

In this case, the humble 555 is pressed into service. It runs as an oscillator, with its frequency varying depending on the user’s hand position. There’s one each for pitch and volume, naturally, using a clamp and spoon as antennas. The C64 then reads the frequency the 555s are oscillating at, and then converts these into pitch and volume data to be fed to the SID audio chip.

[Linus Åkesson] demonstrates the build ably by performing a slow rendition of Amazing Grace. The SID synthesizer chip in the C64 does a passable job emulating a theremin, used here with a modulated pulse wave sound. It’s an impressive build and one we fully expect to see at a big chiptune show sooner rather than later. We’re almost surprised nobody came out with a C64 Theremin cartridge back in the day.

We’ve seen other fancy theremin-inspired builds recently too, like this light-based design.

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New OS For Commodore 64 Adds Modern Features

July 28, 2022 by 43 Comments

The Commodore 64 was a revolutionary computer for its day and age. After four decades, though, it gets harder and harder to use these computers for anything more than educational or hobby electronics projects. [Gregory Nacu] is fiercly determined to challenge this idea, though, and has gone to great extremes to make this hardware still relevant in the modern age by writing a completely new operating system for the Commodore machines.

Known as C64OS, it squeezes everything it can out of the 8 bit processor and 64 kB of memory. The new OS includes switchable desktop workspaces, a windowing system, draggable icons, a Mac-style menu bar at the top, and drop-down menus for the icons (known as aliases in the demonstrations). The filesystem is largely revamped as well and enables a more modern directory system to be used. There are still some limitations like a screen resolution of 320×200 pixels and a fixed color palette which only allows for a handful of colors, but this OS might give Windows 3.1 a run for its money.

The project is still being actively developed but it has come a long way into a fairly usable state. It can be run on original hardware as well as long as you have a method of getting the image to the antique machine somehow. If not, the OS can likely run on any number of C64 emulators we’ve featured in the past.

Thanks to [Stephen] for the tip!

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TensorFlow Lite – On A Commodore 64

July 6, 2022 by 4 Comments

TensorFlow is a machine learning and AI library that has enabled so much and brought AI within the reach of most developers. But it’s fair to say that it’s not for the less powerful computers. For them there’s TensorFlow Lite, in which a model is created on a larger machine and exported to a microcontroller or similarly resource-constrained one. [Nick Bild] has probably taken this to its extreme though, by achieving this feat on a Commodore 64. Not just that, but he’s also done it using Commodore BASIC.

TensorFlow Lite works by the model being created as a C array which is then parsed and run by an interpreter on the microcontroller. This is a little beyond the capabilities of the mighty 64, so he has instead created a Python script that does the job of the interpreter and produces Commodore BASIC code that can run on the 64. The trusty Commodore was one of the more powerful home computers of its day, but we’re fairly certain that its designers never in their wildest dreams expected it to be capable of this!

If you’re interested to know more about TensorFlow Lite, we’ve covered it in the past.

Header: MOS6502, CC BY-SA 3.0.

Will The Real Commodore Please Stand Up?

June 16, 2022 by 27 Comments

The Commodore 64 is a much-loved 8-bit retro computer that first appeared in 1982 and finally faded away around a decade later. The Commodore company started by [Jack Tramiel] went on to make the Amiga, and eventually ceased trading some time in the late 1990s. All history, now kept alive only by enthusiasts, right? Well, not quite, as the C64 has been the subject of a number of revivals both miniature and full-sized over the years. The latest came in the form of a Kickstarter for the C64x, a seemingly legitimately-branded Commodore 64-shaped PC, but it seems that has now been paused due to a complaint from an Italian company claiming to be the real heirs of Commodore. So will the real Commodore please stand up?

The origin of the Kickstarter C64x breadbin C64 PC is well enough documented, having its roots in a legitimate 2010 offering for which the person behind the C64x appears to have gained the rights. The Italian company is also called Commodore and uses the familiar branding from the glory days to sell some Commodore-themed games, novelties, and a tablet computer, but its website is a little tight-lipped about how it came by the use of that IP. Could it have come upon those rights through the 1990s German owner of the brand, Escom? We’d be fascinated to know.

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A (Nearly All) New Commodore 64

May 4, 2022 by 10 Comments

The Commodore 64 remains one of the most influential of the 8-bit home computers four decades after its launch, so not surprisingly there is a huge enthusiast community surrounding it. With so many produced over the years it was available one might think that there would be no shortage of surviving specimens, but sadly time and component failure have taken their toll and the classic micro is not always the most reliable kid on the block. Thus a cottage industry has sprung up supplying C64 parts, leading [The Retro Shack] to have a go at making a new one entirely from scratch.

As you can see in the video below the break it’s not quite an entirely new ’64, as parts including some of the custom silicon come from failed boards. The PCB is a modern recreation of the original and the SID sound chip is an ARMsid though, and most of the parts come from a handy bagged-up kit that makes assembling the BoM much easier. Instead of the big silver box of the original RF modulator is a modern composite board, and there are a few issues with minor connector part differences.

Assembly is simply a very long through-hole soldering process, and once he’d completed it there was the expected refusal to work. We’ve all been there, and eventually he traced it to an incorrectly fitted chip. If you think you’ve seen a few brand new C64s here before you’d be correct, one of them even used LEGO for those elusive keycaps.

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Commodore C64: The Most Popular Home Computer Ever Turns 40

April 20, 2022 by 107 Comments

This year marks the anniversary of the most popular selling home computer ever, the Commodore 64, which made its debut in 1982. Note that I am saying “home computer” and not personal computer (PC) because back then the term PC was not yet in use for home computer users.

Some of you have probably not heard of Commodore, which is kind of sad, though there is a simple reason why — Commodore is no longer around to maintain its legacy. If one were to watch a documentary about the 1980s they may see a picture of an Apple computer or its founders but most likely would not see a picture of a Commodore computer in spite of selling tens of millions of units.

To understand the success of the C64 I would first back up and talk about the fabled era of home computers which starts with understanding the microprocessor of the day, the venerable 6502. Check out the video and follow along below.

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Commodore 64 Monitor Traces I/O Calls, Eases Debugging

February 18, 2022 by 7 Comments

Developing for the Commodore 64 can be a rewarding retrocomputing experience, and thanks to [Dave Van Wagner], things are easier with his C64 IO_Monitor project, which opens the door to logging and tracing Kernal I/O calls for closer inspection. That’s not a typo, by the way. Kernal is what handles the C64’s low-level OS routines. Amusingly, as the story goes, it did in fact originate as a misspelling of kernel, but the name stuck.

What [Dave]’s program does is trace and log all input and output calls going through Kernal, which includes just about any function one might imagine. Things like keyboard input, screen output, and disk or tape I/O are all dutifully counted and logged, allowing one to really peek under the hood at a low level when doing any kind of development work. This kind of tool has turned out to be pretty handy given [Dave]’s penchant for porting Commodore emulators to a variety of (sometimes unusual) platforms.

Interested in giving it a spin? Head to the project’s GitHub repository for all the necessary files as well as some usage details, and enjoy making debugging and development a little less opaque than it otherwise would be.