commodore 64

131 Articles

a Coleco Adams console on a desk

Coleco Adam: A Commodore 64 Competitor, Almost

July 21, 2025 by 36 Comments

For a brief, buzzing moment in 1983, the Coleco Adam looked like it might out-64 the Commodore 64. Announced with lots of ambition, this 8-bit marvel promised a complete computing package: a keyboard, digital storage, printer, and all for under $600. An important fact was that it could morph your ColecoVision into a full-fledged CP/M-compatible computer. So far this sounds like a hacker’s dream: modular, upgradeable, and… misunderstood.

The reality was glorious chaos. The Adam used a daisy-wheel printer as a power supply (yes, really), cassettes that demagnetized themselves, and a launch delayed into oblivion. Yet beneath the comedy of errors lurked something quite tempting: a Z80-based system with MSX-like architecture and just enough off-the-shelf parts to make clone fantasies plausible. Developers could have ported MSX software in weeks. Had Coleco shipped stable units on time, the Adam might well have eaten the C64’s lunch – while inspiring a new class of hybrid machines.

Instead, it became a collector’s oddball. But for the rest of us, it is a retro relic that invites us to ponder – or even start building: what if modular computing had gone mainstream in 1983?

Let’s Buy Commodore! Well, Somebody Is.

June 7, 2025 by 61 Comments

When a man wearing an Atari T-shirt tells you he’s buying Commodore it sounds like the plot for an improbable 1980s movie in which Nolan Bushnell and Jack Tramiel do battle before a neon synthwave sunset to a pulsating chiptune soundtrack. But here on the screen there’s that guy doing just that, It’s [Retro Recipes], and in the video below he’s assembling a licensing deal for the Commodore brand portfolio from the distant descendant of the Commodore of old.

It’s a fascinating story and we commend him for tracing a path through the mess that unfolded for Commodore in the 1990s. We tried the same research path with a friend a few years ago and ended up with an anonymous Dutch paper company that wouldn’t answer our calls, so we’re impressed. In conjunction with several other players in the Commodore retrocomputing world he’s trying to assemble a favourable percentage deal for manufacturers of new parts, computers, and other goodies, and we’re pleased to see that it’s for the smaller player as much as for the industry giant.

When looking at a story like this though, it’s important not to let your view become clouded by those rose tinted glasses. While it’s great that we’re likely to see a bunch of new Commodore-branded Commodore 64s and parts, there are many pitfalls in taking it beyond that. We’ve seen the Commodore logo on too many regrettable licensed products in the past, and we fear it might be too tempting for it to end up on yet another disappointing all-in-one video game or just another budget PC. If something new comes out under the Commodore brand we’d like it to be really special, exploiting new ground in the way the Amiga did back in the day. We can hope, because the alternative has dragged other famous brands through the mud in recent years.

If you want an insight into the roots of the original Commodore’s demise, have a read of our Hackaday colleague [Bil Herd]’s autobiography.

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The Commodore 64 Gets An HDMI Upgrade

May 25, 2025 by 39 Comments

The Commodore 64 may remain the best selling computer of all time, but it has one major flaw. It doesn’t have HDMI! That makes it a total pain to use with modern displays. Thankfully, [Side Projects Lab] has whipped up an HDMI output board to solve this concerning oversight from the original designers.

The project was inspired by work by [Copper Dragon], who whipped up a nifty RGB output board. This device worked by reading the inputs to the C64’s VIC II graphics chip, which it then used to recreate a pixel-perfect video frames to then produce a quality analog video output. [Side Projects Lab] figured the same interception technique would be useful for producing a quality HDMI output.

The result was the HD-64. It sits inside the C64 in place of the original RF modulator. It uses an interleaver socket to capture digital signals going to the VIC II. It then feeds these signals to an emulated VIC II running inside an FPGA, which creates the pixel-perfect screen representation and synthesizes the proper digital HDMI output. Meanwhile, the analog audio output from the SID chip is captured from the RF modulator’s original header, and sent out via the HDMI output as well. The default output is super-sharp, but the device can be configured to allow scanlines and anti-aliasing if that’s more to your tastes.

If you want to hook your C64 up to a modern screen, this is going to be one of the tidiest and sharpest ways to do it. We’ve seen similar hacks for other platforms before, too. Video after the break.

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C64 on desk with NFC TeensyROM and game token

TeensyROM NFC Game Loading On The C64

May 23, 2025 by 6 Comments

When retro computing nostalgia meets modern wireless wizardry, you get a near-magical tap-to-load experience. It’ll turn your Commodore 64 into a console-like system, complete with physical game cards. Inspired by TapTo for MiSTer, this latest hack brings NFC magic to real hardware using the TeensyROM. It’s been out there for a while, but it might not have caught your attention as of yet. Developed by [Sensorium] and showcased by YouTuber [StatMat], this project is a tactile, techie love letter to the past.

At the heart of it is the TeensyROM cartridge, which – thanks to some clever firmware modding – now supports reading NFC tags. These are writable NTag215 cards storing the path to game files on the Teensy’s SD card. Tap a tag to the NFC reader, and the TeensyROM boots your game. No need to fumble with LOAD “*”,8,1. That’s not only cool, it’s convenient – especially for retro demo setups.

What truly sets this apart is the reintroduction of physical tokens. Each game lives on its own custom-designed card, styled after PC Engine HuCards or printed with holographic vinyl. It’s a tangible, collectible gimmick that echoes the golden days of floppies and cartridges – but with 2020s tech underneath. Watch it here.

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LLM Ported To The C64, Kinda

May 3, 2025 by 8 Comments

“If there’s one thing the Commodore 64 is missing, it’s a large language model,” is a phrase nobody has uttered on this Earth. Yet, you could run one, if you so desired, thanks to [ytm] and the Llama2.c64 project!

[ytm] did the hard work of porting the Llama 2 model to the most popular computer ever made. Of course, as you might expect, the ancient 8-bit machine doesn’t really have the stones to run an LLM on its own. You will need one rather significant upgrade, in the form of 2 MB additional RAM via a C64 REU.

Now, don’t get ahead of things—this is no wide-ranging ChatGPT clone. It’s not going to do your homework, counsel you on your failed marriage, or solve the geopolitical crisis in your local region. Instead, you’re getting the 260 K tinystories model, which is a tad more limited. In [ytm]’s words… “Imagine prompting a 3-year-old child with the beginning of a story — they will continue it to the best of their vocabulary and abilities.”

It might not be supremely capable, but there’s something fun about seeing such a model talking back on an old-school C64 display. If you’ve been hacking away at your own C64 projects, don’t hesitate to let us know. We certainly can’t get enough of them!

Thanks to [ytm] for the tip!

Crossing Commodore Signal Cables On Purpose

April 29, 2025 by 19 Comments

On a Commodore 64, the computer is normally connected to a monitor with one composite video cable and to an audio device with a second, identical (although uniquely colored) cable. The signals passed through these cables are analog, each generated by a dedicated chip on the computer. Many C64 users may have accidentally swapped these cables when first setting up their machines, but [Matthias] wondered if this could be done purposefully — generating video with the audio hardware and vice versa.

Getting an audio signal from the video hardware on the Commodore is simple enough. The chips here operate at well over the needed frequency for even the best audio equipment, so it’s a relatively straightforward matter of generating an appropriate output wave. The audio hardware, on the other hand, is much less performative by comparison. The only component here capable of generating a fast enough signal to be understood by display hardware of the time is actually the volume register, although due to a filter on the chip the output is always going to be a bit blurred. But this setup is good enough to generate large text and some other features as well.

There are a few other constraints here as well, namely that loading the demos that [Matthias] has written takes so long that the audio can’t be paused while this happens and has to be bit-banged the entire time. It’s an in-depth project that shows mastery of the retro hardware, and for some other C64 demos take a look at this one which is written in just 256 bytes.

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Adding An Atari Joystick Port To TheC64 USB Joystick

April 24, 2025 by 1 Comment

“TheC64” is a popular recreation of the best selling computer of all time, the original Commodore 64. [10p6] enjoys hacking on this platform, and recently whipped up a new mod — adding a 9-pin Atari joystick connector for convenience.

When it comes to TheC64 units, they ship with joysticks that look retro, but aren’t. These joysticks actually communicate with the hardware over USB. [10p6]’s hack was to add an additional 9-pin Atari joystick connector into the joystick itself. It’s a popular mod amongst owners of TheC64 and the C64 Mini. All one needs to do is hook up a 9-pin connector to the right points on the joystick’s PCB. Then, it effectively acts as a pass-through adapter for hooking up other joysticks to the system.

While this hack could have been achieved by simply chopping away at the plastic housing of the original joystick, [10p6] went a tidier route. Instead, the joystick was granted a new 3D printed base that had a perfect mounting spot for the 9-pin connector. Clean!

We’ve seen some great hacks from [10p6] lately, like the neat reimagined “C64C” build that actually appears in this project video, too.

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