Docs / About C64 READY.

About C64 READY.#

Switch it on and it's the 80s again: the blue boot screen, the blinking cursor, the 1541 chattering awake, a SID tune warming up as the demo kicks in. That feeling, pure nostalgia 🕹️, is what C64 READY. is really about.

It's a Commodore 64 rebuilt from the silicon up, running right in your browser. No plugins, nothing to install. Just open it and play.

What it stands for#

• Easy, never bloated. It should feel like flipping a switch, not flying a plane.
• Faithful enough to run anything. If a real breadbin runs it, so does this.
• Runs anywhere. Desktop or phone, online or offline, and it installs as its own app if you want.
• Serious emulation, casual vibes. Cycle-exact silicon underneath, built for the sheer joy of it.

What it does#

• Runs the demos that stump other emulators. The wildest custom fastloaders load and run, cycle for cycle. → the 1541 drive
• Backed by more than 2,400 labeled tests. The default npm test suite spans about 350 registered spec files covering the CPU, VIC-II, SID, CIA, PLA, drive, datasette, cartridges, input, save states, and integration edge cases. → the test suite
• Save state, resume anytime. Snapshot the exact machine to a file and pick up right where you left off, mid-demo or mid-boss-fight. → the user guide
• Sounds the way it was written. Both SID chips, 6581 and 8580, filters and all. → the SID
• Bring your own everything. Disk, tape, cartridge or .prg; joystick, gamepad or keyboard. → getting started

Curious how it all works? The technical docs go chip by chip.

Retro Vibes#

Step into an 80s bedroom bathed in synthwave light, your C64 humming on the desk with the demo playing live on its 1702 monitor. It's the emulator, but make it a scene, and you can slip on a headset and pull up a chair, because it runs in VR, too. → Retro Vibes

How it started#

It began as a plan to drop a SID tune into my vibe-coded retro game, Cosmic Bounce (which already had a MOD player). The SID player came together fast, and then the obvious-in-hindsight question hit: could I build the whole machine in a browser? A breadbin's worth of tokens and late nights later, here we are.

And along the way it became the best kind of learning project: a deep dive into every corner of the C64's hardware and software, and where I learned to build something this complex by vibe coding.

I love this machine: the blocky charset, the PETSCII art, the rasterbar demos that still bend my brain forty years on, the chiptune scene that never stopped composing. To every demo coder, SID composer, cracker, doc author, emu hacker and glorious lunatic keeping the C64 alive: thank you. C64 READY. stands on your shoulders.

Full references and acknowledgements are in Specifications, source material and credits.

Known issues#

It's a work in progress: a few small visual glitches remain, and there's more performance to squeeze out. Nearly everything runs faithfully, but now and then you may spot something off. The current list lives in the known-issues doc. The code lives on GitHub; please file an issue for anything you run into.

About the author#

Hi, I'm Morten (RetroMorty). Back in the 90s I ran with the PC demo scene in the group Twilight Zone; under Twilight Zone Software we built the game Interpose, where I was project manager and programmer, years that left me fluent in x86 assembly and passingly dangerous in C64 assembly. In 2000 I founded Enonic, where I'm still CEO today.

The love never left: three C64s, a Commodore 1084S monitor, and a good stash of games and joysticks are always within reach. C64 READY. is my love letter to the machine and the scene that started it all.

Follow C64 READY. on Facebook, contact me on LinkedIn, or email mortyeriksen@gmail.com.

License and source#

C64 READY. is free software under the GNU General Public License, version 3 or later, distributed without warranty; see the GPL for copying and modification rights. The full source lives on GitHub, and the third-party credits, licenses, and trademark disclaimer are collected in the notice.