Akai S2000 Mod: Rosetta OS, effects without the EB16
Custom firmware for the Akai S2000 (S-2000) sampler, built from your own OS 2.0 disk: reverb, echo and reverse delay with no EB16 effects board, live input effects, a built-in synth rompler and MPC-style menus. Boots from a Gotek. Free, open source, and tested on a real S2000.
Reverb and effects without the EB16Reverbs (ROOM, HALL, PLATE), ECHO, PINGPONG, DUB and RESO run on the voice chip's own hidden delay engine, with an EFFECTS page for type, wet, time, feedback and rate. No effects board needed.
Reverse delayREVERSE and REV HALL on played notes: chunks of what you play come back backwards, and REV HALL flips the hall's tail so it swells up instead of dying away.
Live input effects + live reverseOn the sampling screen the input goes through the effects: you hear it live, the take still records dry. A live reverse delay has its own menu (a BPM you set, note division, feedback, attack, release, octave, ping-pong), and its knobs save to the boot floppy. While it runs, the monitor is about 12 ms late.
ROSETTA ROM synth romplerBand-limited saw, square, pulse, triangle and sine waves plus 9 synth programs (PAD, BASS, PLUCK, SUPERSAW...) that load with the OS: playable at power-on, no extra disk.
Analog-style synth layerPer-voice pitch drift, detune spread and a filter LFO on MIDI CC 20-25. All at 0 = exactly stock.
MPC-style workflowA HOME hub (LOAD / effect / EDIT), a back-one-level key, an EDIT PROGRAM menu, a sampling screen where REC starts and stops the take (mono for now), LOAD and SAVE in one press when no flash ROM is fitted, and PLAY auditions the current sample when no program is loaded.
Room to grow64 KB of extra code space loaded from the boot floppy, hot reload over MIDI and a SysEx lab that pokes the sound chip live.
Every feature above is confirmed on a real S2000. Known issue: the moving effects (CHORUS, FLANGER, JUNO, TAPE) crackle on held chords, so they're listed under In progress. It's custom firmware that loads from the boot floppy, like the stock OS 2.0: nothing touches ROM or flash, so booting your stock disk gives you a stock S2000 again.
Listen
Audio warning: turn your volume down first. The test sounds are harsh: noise bursts and a 1 kHz beep.
Recorded from a real S2000 running Rosetta 0.10, an early build (before the reverse delay, live input effects, DUB, RESO and the synth): each effect gets three noise hits (OFF, ROOM, HALL, PLATE, ECHO, PINGPONG, CHORUS, FLANGER), then a 1 kHz beep dry, through CHORUS and through FLANGER.
How it works
Image your own S2000 OS 2.0 floppy. No Akai code is shipped: the build tool patches your disk.
Run the build tool (Python 3.10+ with numpy, NASM, and an HFE template of an Akai HD floppy). It checks every stock byte before patching and writes a boot floppy image.
Copy it to a Gotek (FlashFloppy, nav-mode = indexed) USB stick as DSKA0000.hfe, the only image on the stick, and boot the S2000. The boot dragon flies, then the HOME screen.
Full steps, the menus and the hidden delay engine's story are in the README. Notes for other S2000 / S3000 hackers (the voice chip, loops, the filter) are in Walls we hit.
In progress
Crackle-free moving effectsCHORUS, FLANGER, JUNO and TAPE run on hardware but crackle on held chords (moving delay taps). The cause is still being hunted; the static effects (ROOM, HALL, PLATE, ECHO, PINGPONG, DUB, RESO) are clean.
SYNTH pageSynth editing on the MULTI key: a mode menu, then 4 pages of knobs (wave, filter, envelopes, drift, detune, LFO) on any program. Runs in the emulator; hardware test, FAKE FM and WAVETABLE modes next.
8 individual outsAn open clone of the IB-208P output board: PCM69 DACs, through-hole parts, the 34-pin header the S2000 already has.
MIDI CC for the effectsEffect type, wet, time, feedback and rate on MIDI CCs (a fan request).
