DOOM OS
Firmware for SP-404MKII (Roland)
Heavily modified 5.52 firmware that adds a graphical pattern sequencer, piano roll, live recording, mixer, effect automation and undo in a "shadow OS" opened with REMAIN + SUB PAD.
by Quintus Oostendorp (Klangfeld Labs)
- Distribution
- Patches a stock file you supply
- Requires stock
- 5.52
- License notes
- Custom license. Free to use, including for commercial music. You may not pass on the patch, patcher or a patched file, or modify or imitate DOOM OS. The repository contains the browser patcher, not the firmware changes in readable form.
- Source
- github.com https://github.com/klangfeld-labs/doom-os
- Homepage
- klangfeldlabs.com https://klangfeldlabs.com/doom-os
- sequencer
- performance
- ui
- os
Description
The shadow OS sits beside the stock firmware and everything from the original firmware still works. Adds a grid pattern sequencer you can edit while it plays, a piano roll played on the pads, live recording with rehearse mode, quantise and swing, eight pattern tools, a mixer with level meters, recorded and step-edited effect automation, 12-step undo and redo, custom shortcuts and a help mode. Patterns are written to a new file before the old one is removed. The author lists built-in instruments, song mode, a clip launcher, a sample editor and an add-on system as possible future work.
Install notes
Load Roland's official 5.52 SP404MKII_APP1.bin into the browser patcher, which checks the result against published checksums. Copy the patched file to the SD card, hold SHIFT while powering on and press the VALUE knob. Running the updater with Roland's original file restores stock.
Version history
| Version | Date |
|---|---|
| 0.6.2-alpha (build 3824) | 2026-10-06 |
| 0.6.1-alpha | 2026-10-04 |
| 0.6-alpha | 2026-09-29 |