Freakier Firmware Lab

Roland SP-404MKII · unofficial

SP-404MKII

Sampler · 16 pads × 10 banks

A playable 3D sampler with ten genre banks, bus effects, resampling and patterns, plus a Screen Loader that puts your own art on the real unit's display today.

Side-Piece

Side-Piece, an unofficial custom OS layer for the Roland SP-404MKII. It sits on top of Roland's own system and adds what we wish the sampler had.

Releasing soon. The first build is in final testing. Nothing is downloadable yet. Want something for your SP today? The Screen Loader works now and doesn't touch the firmware at all.

Don't update your SP-404MKII's firmware until the compatibility table says ✅. A new official version can arrive before we've ported to it. Keep your own copy of the official firmware file you're running now.

Launch gates

  1. Played on our own unit (open)

    The exact build is flashed onto our own instrument and played, not only run in the emulator.

  2. Recovery rehearsed (open)

    We back up the unit data and bootloader, then walk the recovery guide end to end, before anyone else flashes it.

  3. Legal review (open)

    A flat-fee review with an IP lawyer: the terms, the disclaimers and the name.

  4. Ten clean beta reports (open)

    Paid packs only: ten testers, no unrecovered bricks.

Tools

Free tools for the SP-404MKII. They run in your browser, and nothing you give them is uploaded.

SP-404 Screen Loader

Live

Turn your own pictures or an animated GIF into the SP-404MKII's power-on images and screen saver. Download the SD-card folder as a ZIP, or write it straight to the card in Chrome or Edge.

Uses Roland's own opening-screen feature. No firmware involved.

Open SP-404 Screen Loader →

Explore & Learn

32 voices, bus routing, resampling, pattern recording and 28 of the 46 effects, with synthesised kits. None of it is Roland's code or samples.

SP-404MKII simulator3D · 448 KB · loads on click

The simulator is written from Roland’s manuals and update notes. Start with the basics, make a track from the ten genre banks, then walk through what each Roland system update added.

Lessons marked Preview show Side-Piece features that aren’t released yet.

Lessons

Start here · Roland 1.00 basics

011.00Pads and banksPower on, play the factory kit, and move between the ten banks.2 minStart lesson →021.00Bus effectsTurn on an effect, shape it with the three CTRL knobs, and choose which bus each pad uses.3 minStart lesson →031.00Choose any effect with MFXHold MFX, scroll the list with VALUE, let go to switch it on.2 minStart lesson →041.00Shape a samplePitch and speed, gate, loop and reverse: the pad's own settings.3 minStart lesson →051.00ResampleRecord what you play, effects and all, onto an empty pad.2 minStart lesson →061.00Record a patternPATTERN SELECT, REC, pick a pad, play, and loop it.3 minStart lesson →

Make tracks · ten banks, one genre each

07ModelThe readout: pads, knobs, buttonsThe panel at the top left shows the display, what is on every pad, what each knob edits, and every button. All of it can be played.3 minStart lesson →08ModelTen banks, one genre eachEvery bank is a full kit in one style, laid out the same way: drums, bass, chords, loops.3 minStart lesson →09ModelPlay the factory patternsEach genre bank has four patterns: drums, drums and bass, the full groove, and a breakdown.3 minStart lesson →10ModelJam over a patternStart a drum pattern, go back to the samples while it keeps playing, and play bass and chords on top.3 minStart lesson →11ModelBuild a track from nothingRecord your own house pattern: set length and tempo, lay down the kick, then overdub clap and bass.5 minStart lesson →12ModelBounce a groove to one padResample a playing pattern into an empty pad, so a whole groove becomes one sample.4 minStart lesson →13ModelPerform with the effectsRide the filter, cut the bass with the isolator and freeze a slice with the looper while a groove plays.4 minStart lesson →

Side-Piece · our firmware

14Build 01Check which firmware is runningSHIFT + pad 13, SYSTEM, VERSION tab: the screen that proves a Build is on the unit.2 minStart lesson →15Works todayThe Side-Piece boot screenTwo Side-Piece opening images at power-on. Put them on your unit today as startup_1.bmp and startup_2.bmp, no flashing needed.3 minStart lesson →16Draft · rejectedSHIFT + VOLUME: input levelPatch 003's first draft: SHIFT + VOLUME sets the input level from the main screen. Review rejected it and it is being redesigned, so the real one will differ.3 minStart lesson →17Build 01The USB input gain experimentWhy the iPad clips, where Build 01 turns the gain down, and the test that tells us whether it worked.3 minStart lesson →18SafetyGo back to Roland's firmwareThe recovery path: an SD card with Roland's file on its own, SHIFT at power-on, VALUE to update.2 minStart lesson →

Roland updates · what each one added

191.11 · Oct 20211.11: effect grab, bus swap, skip-backThe first big update: hold-to-use effects, swapping the two buses, bank-wide gate, and skip-back sampling.3 minStart lesson →201.13–1.14 · 20221.13 and 1.14: fixed velocity, pad mute, live modePer-pad fixed velocity, muting pads while a pattern plays, bank-wide BPM sync, and a stage-safe live mode.3 minStart lesson →212.00 · Jul 20222.00: TR-REC, chromatic, 16 undosStep recording in TR style, chromatic playing recorded into patterns, new reverbs and delays, and USB audio routing.3 minStart lesson →223.00 · Mar 20233.00: bounce, motion rec, one-shotBounce a pattern to a sample, record effect moves into patterns, one-shot pads and DJ cue points.3 minStart lesson →234.04 · Apr 20244.0x: looper, groove, sound generatorA looper on MARK, groove and humanize, a built-in tone source, sample merge, rename, and SP-404SX project import.3 minStart lesson →245.00 · Apr 20255.0x: Serato DJ and app connectionSerato DJ and Serato Studio over USB, the sound generator while resampling, and skip-back in DJ mode.3 minStart lesson →255.50–5.52 · 20265.50: side-chain compressionSide-chain compression from a pad or pattern, exFAT cards, and 5.52, the version this model and Side-Piece are built on.3 minStart lesson →