This browser can't talk to MIDI devices.
Use Chrome, Edge or Opera on a computer, or Chrome on Android. Safari (Mac, iPad, iPhone) has no Web MIDI;
on an iPad, a browser app with Web MIDI support works.
MIDI access was granted without SysEx, so the Custom build + SysEx target can't send its
messages. Allow SysEx for this site in the browser's settings and reconnect.
Drag a value on the screen up or down to change it, or click it for a menu.
Saved patches
No saved patches yet. Save stores the current sound in this browser; export them to move them to another device.
Sound
Modulation
Filter
Amplitude
Voices
Setup
Paddles, paddle buttons, video and Cynthcart's MIDI channel. These aren't part of patches (presets never change them on the C64). The page can't see changes made with the C64's keys, so press Send setup to bring the C64 in line.
Play
C3
Computer keys play two octaves, like Cynthcart: Z S X D C V G B H N J M , for the lower one, Q 2 W 3 E R 5 T 6 Y 7 U I for the upper one.
How it works
- Targets. Cynthcart 2.0 uses the original MIDI map (resonance only reaches 7 over MIDI, no PULS3, pulse width is uneven); Cynthcart 2.0.1F is 2.0.1 with the resonance and pulse-width bugs fixed. Custom build (CC only) is the Kerberos build before SysEx; Custom build + SysEx sets everything exactly, including octave, tuning, filter type and per-voice filter routing, and shows the patch name on the C64.
- Greyed-out controls can't be reached on the chosen target; their value comes from the base preset.
- Setup (paddles, paddle buttons, video, Cynthcart's MIDI channel) needs the SysEx firmware; the CC-only build can set video (no full screen). Setting Cynthcart to a channel also switches this page to it.
- Sending a patch loads the base preset first, then sets every value on top. On 2.0, only values that differ from the base preset are sent.
- The page is the source of truth: Cynthcart can't send its state back, so changes made on the C64 keyboard aren't shown here.
- Patches are kept in this browser. Export them to back them up or move them to another device.