"DOOM OS is a heavily modified version of the original 5.52 firmware. It adds a graphical pattern sequencer, a mixer, effect automation, custom shortcuts and more, and improves parts of the original firmware. You patch it yourself, in your browser, using the official firmware file from Roland."
Have a look:
https://klangfeldlabs.com/posts/2026-09 ... -sp404mk2/
It's kind like the JJ OS for the MPC and adds features on top of the existing os:
Pattern sequencer with a graphical interface: see and edit your pattern as a grid while it plays
Piano roll: play melodies in on the pads
Live recording with a rehearse mode, quantise, swing, fixed velocity and note length
Eight pattern tools: quantise, swing, shift, double, halve, reverse, humanise, transpose
Track and pattern settings: mute, solo, volume, swap pad, paste, clear, tempo, pattern length
Mixer with a live level meter for every track
Effect automation: record your effect knob moves and edit them step by step
Zoomed view of four tracks
Undo and redo, 12 steps
Help mode: press any control to see what it does
Custom shortcuts (key combos)
A DOOM OS tab in the system settings
Six boot animations
I haven't tried it myself, but it seems not that risky to switch to doom os.
https://github.com/klangfeld-labs/doom-os