The synth.
Paul Slocum’s Cynthcart running on an emulated Commodore 64, so what you hear is the SID chip’s own oscillators, filter and envelopes.
Real C64 emulationFREE · PLAY IT IN YOUR BROWSER
My Commodore 64 synth.
Play it free.
Seven years in the making: a real Commodore 64 with two SID chips in true stereo, a knob panel from Look Mum No Computer, and Paul Slocum’s Cynthcart. Now you can play it right here in your browser — the full synth and all 30 presets.
Modelled on the real hardwareAll 30 presetsFree · nothing to install
Get my free link 
THE SYNTH IN YOUR BROWSER
Knobs, keys and that SID sound.
Three ways to play it, all at once:
- The knobs. They’re photographs of the real panel. Drag up or down to turn them.
- Your computer keyboard. A–K for the white keys, W E T Y U for the black ones, Z and X to change octave.
- The on-screen piano. Click and play.
WHAT YOU GET
The real thing.
Without the soldering.
All 30 presets.
Basses, leads and pure 8-bit noise, ready to play. Turn the knobs and make them your own.
30 presetsYour own link.
Pop in your email and I’ll send you a personal link. Click it and the synth opens in your browser, ready to play.
Free · nothing to installTHE MACHINE BEHIND THE SYNTH
Seven years at the bench.
In pictures.
From the bare circuit board to the finished machine: the real Commodore 64 the browser version is modelled on.
WATCH THE WHOLE BUILD
Seven years. Seven episodes.
The whole story, from buying a Commodore 64 again to the finished synth — with The 8-Bit Guy and Look Mum No Computer along the way.
THE FINALE
The Commodore 64 Synthesizer — Ep.7 It’s Finished!!
Seven years on, the synth is finished: two SID chips in true stereo, the knob panel, the case, and the first proper play.
Play it freeEp.1 — Where it started
I buy a Commodore 64 again, test its SID chip and start building my synth.
Ep.2 — With The 8-Bit Guy
The 8-Bit Guy helps me plan it: knobs, SID hum, screens and keyboards.
Ep.3 — With Look Mum No Computer
Sam helps me wire two SID chips into the C64 for six voices.
Ep.4 — The knob interface
Look Mum No Computer sends me a knob panel, and I wire it up.
Ep.5 — The display prototype
Sam joins me on a call, then I test a display on the synth.
Ep.6 — Assembling it
The wooden case, the electronics and a first test.
WHERE YOU GO NEXT
Understand every synth you play.
Oscillators, filters, envelopes: the SID chip has them all, and so does every synthesizer since. Learn how they work and you can get the sound you hear in your head out of any synth.
The course is optional. The C64 synth is yours to play.
THE FULL VIDEO COURSE
Synthesizer Guru
43 lessons in my studio, from the first oscillator to your own preset library.
- Oscillators, filters, envelopes and LFOs, in depth
- Program sounds from scratch on any synth, hardware or software
- Recreate iconic synth sounds from classic records
Paid course · See the lessons and current price
Before you play.
Do I need a real Commodore 64?
No. It runs in your web browser. The Commodore 64 is emulated, and the knobs and keyboard are on screen.
How do I play it?
Drag the knobs up or down, play the keys on your computer keyboard (A to K, plus W E T Y U for the black keys, Z and X for octaves), or click the on-screen piano. Headphones or speakers recommended.
Is it really free?
Yes. The full synth and all 30 presets, no payment details needed.
What happens when I enter my email?
I email you a personal link that opens the synth. Your email also joins the Doctor Mix newsletter — mixing tips and the occasional offer — and you can unsubscribe in one click any time. See our Privacy Policy.
Who made it?
I built the hardware over seven years, with The 8-Bit Guy and Sam from Look Mum No Computer, who designed the knob panel. The synth software is Cynthcart, by Paul Slocum. The browser version is a Doctor Mix × Look Mum No Computer tribute.
SEVEN YEARS OF BUILDING. ONE CLICK TO PLAY.