ACID FM

From the project's README ("ACID FM"):

IDM / braindance firmware for the M-VAVE FM-1. ACID FM is becoming a firmware with virtual analog, FM, chopped breakbeats you load yourself, and a generator that writes whole songs on the device (planned, see Status). Acid-coloured, in the spirit of Aphex Twin, Boards of Canada and the Rephlex catalogue.

Install (Chrome or Edge, over USB) · Try it in the browser · Manual

Status: 0.6

0.6 is SAVE, the MENU and the dialogs in the ACID look (piece 3c-2), on top of 0.5.2:

• SAVE is SOUND, SONG, PROJECT and MORE. SOUND lists the 32 user slots; SONG puts the sections on top and the song's rows under them as chips; PROJECT shows four cards, a dot on the one with changes not stored, and warns on LOAD only when there are some; the tools are in MORE.
• The MENU is AUDIO, CLICK, CONTROLS and MORE; ABOUT and PROFILE are restyled.
• One full-screen dialog for every confirmation: it says what is lost and how to get it back.
• PLAYS (SEQ › MORE › TRACK): a track plays only on some loops; you can change it while the music plays.
• The clock rule: under a USB or TRS clock, GEN, the demo and the web editor leave the tempo alone; CPU TEST uses the internal clock and puts CLOCK back.
• The web editor has a per-track MIDI page. The example names are in English. Projects, presets and settings from 0.5 load as before.

Before that, 0.5.2 fixes harsh glitches on some generated songs. A few EXPLORE pieces asked for more than the FM-1's processor can …

Read the full instructions

From the project's README ("Safety"):

Installing firmware is at your own risk. Back up the full flash first (MvaveFM1Unbricker backup). The FM-1's ROM bootloader cannot be overwritten, so a failed install can be recovered (FM-1 Firmware Hub rescue), and the official firmware can always go back on.

Read the full instructions