A free, browser-based MIDI controller for the Roland SP-404 MkII — a single HTML file, no installation, no dependencies, no account.
Live: https://littletools404.github.io/404busdriver/
- Full control of all five effect buses (BUS 1–4 + INPUT): effect selection with real parameter names from the reference manual, six touch faders with relative drag and fine-tune pull-out, bidirectional sync with the hardware encoders.
- Snapshots (8 slots) with JSON export/import.
- XY pad (Kaoss-style, freely mappable, momentary spring-back) and four beat-synced LFOs (incl. random drift), clocked by incoming MIDI clock or tap tempo.
- Play surfaces: chromatic keyboard (CH 16), scale pads with isometric Move-style layout, vocoder keyboard with pitch bend (CH 11), and a pad board incl. a freely assignable custom layout.
- Pattern grid with a quantized markov autopilot, plus a looper remote.
- SP-404 MkII connected via USB-C.
- A browser with Web MIDI: Chrome or Edge on desktop; on iPhone/iPad use the MIDIWeb Browser app (iOS browsers cannot do Web MIDI).
- Effect control works in MIDI Mode A and B; pattern switching needs Mode B with "PC Rx" ON. Details in the built-in manual (Setup > Handbuch).
Full documentation: MANUAL.md — also built into the app (Setup > Manual).
Everything runs locally in your browser. No server, no tracking, no accounts; settings and snapshots live in your browser's localStorage.
This is an unofficial project, not affiliated with or endorsed by Roland Corporation. "SP-404" is a trademark of Roland Corporation. Effect data is derived from the publicly available SP-404MK2 reference manual.
MIT — see LICENSE.