Install, update and the way back

Groove OS is installed from a web page, over one USB cable, from Chrome or Edge. The same page updates it, and the same page puts M-VAVE's own V15 back if you want it. This chapter explains what the install does, how to update safely, what the way back to V15 costs, and what to do if an install is interrupted.

What Groove OS is, and what it is not

Groove OS is a mod of M-VAVE's V15 firmware, not a replacement. It is code added to V15 that takes over the screen, the controls and the note path. The FM engine, MIDI, Bluetooth and the updater stay M-VAVE's. Installing leaves the FM-1's four preset banks, A to D, as they are: out of the factory they hold its 128 DX7 voices, which the sound browser lists as DX7, and a bank you load from the website replaces one of them (see The banks).

While Groove OS runs, the stock screens (its editor, its arpeggiator and sequencer pages, its GLO page) are not reachable: Groove OS's own replace them. The stock interface is one power-on away: see Safe mode.

What you need

Installing

1. Open the Install page, signed in. Connect the FM-1, switch it on, and close other programs that use MIDI (a DAW, an editor, another browser tab).

2. browser: the page says whether Web MIDI with SysEx is available, and whether the browser has allowed it for this site. If it is blocked, allow it in the site settings (the icon left of the address bar).

3. connect: press connect FM-1. The page asks only for the FM-1's identity and shows what it runs (FM-1_015 for stock V15).

4. this build: the page shows the version, its size, and the SHA-256 it will check the download against.

5. before you start: tick the list. Most installs that stop come from one of these, so the button stays off until every box is ticked:

   • a USB data cable, straight into the computer (not a hub, not a cable that only charges);
   • a laptop plugged into power;
   • this tab kept open until the page says it is done;
   • every other program that uses the FM-1 closed: a DAW, an editor, M-VAVE's app, or an installer in another tab;
   • and last, the box that says you understand Groove OS is independent software.

   The boxes are unticked every time you open the page, and again after every install.

6. install: press install. The page downloads the build, checks it against the published SHA-256, and only then offers it to the FM-1.

The install runs in three steps with a restart after each, and takes about three minutes:

The page then waits for the FM-1 to come back and checks that it reports the version it just installed. The screen of the FM-1 is dark while it writes.

If the last step does not finish (the cable, a closed tab), Groove OS still starts, plays and saves your songs. The pages that live in that second area (MAIN FX, KEYS, SETTINGS and the sound editor) show FINISH THE UPDATE AT GROOVE-OS.COM/INSTALL instead. Connect again on the Install page: it sees what is missing and offers Finish the install, which runs only the last step.

The list covers what keeps the install running. If the tab closes anyway, the FM-1 waits in its updater and the page offers finish install (see below). The page keeps the screen awake where the browser allows it (Wake Lock); otherwise it says so, and you switch off sleep for the next few minutes.

When the page says installed, the FM-1 has restarted and reports its new name. If the screen is dark, switch the FM-1 off and on. The boot logo plays, and you are on TRACKS (Getting started). The page then shows what comes next. First, one line: Six courses are on your FM-1: SETTINGS > LEARN. The install puts the six courses on the FM-1 after Groove OS itself, so there is nothing to add: tap GLO, open LEARN and pick one (see Learn on your FM-1). If they were not added this time, the line says so; the FM-1 works as it should, and installing again adds them. Under it, the Start with CORE card: See sound packs opens the sound packs in Sounds, to start with CORE and add genre packs (see Right after you install).

Pro tip: to see what is installed without installing, press connect FM-1 and read your FM-1 runs. Nothing is written until you press install.

Coming from V16

M-VAVE's own app moves an FM-1 to V16 (FM-1_016), and since 21 October 2026 its download page offers only V16. Groove OS installs straight over it: connect shows FM-1_016 · M-VAVE's V16 and install works as from V15, in the same time.

V16 puts its own data in the four preset banks (A to D) and in the FM-1's factory copy of them. So after the install the page checks the banks and puts the FM-1's factory sounds back in A to D, each one read back, and says so in one line: Your presets were restored to the FM-1's factory sounds. The factory copy itself (what SETTINGS > STORAGE > RESET BANK restores from) can't be rewritten from the page, so on a unit V16 ran on, leave RESET BANK alone: it would bring back empty or garbled banks.

After an install over V15 the page writes no bank by itself: banks that hold neither the factory sounds nor a Groove OS bank are your own. Only when the factory copy is damaged too (V16 has been on the unit) does it offer Restore the factory sounds, and nothing is written unless you press it.

Coming from another custom firmware

Groove OS installs over M-VAVE's V15. If your FM-1 runs another custom firmware (for example FM-1+VA), connect shows the version it reports, for example FM-1_093 · another custom firmware, and step 3 offers two steps, one after the other:

1. M-VAVE's V15 goes back on, from M-VAVE's own V15 file, FM-1.fwsc. Since 21 October 2026 M-VAVE's download page offers V16 only, and this step needs V15 (Groove OS is built on it): if you kept V15's FM-1.fwsc from before, choose it on the page or drop it on the box. The page checks it is exactly V15 before the FM-1 is offered a byte, and says so if you choose V16 (that is M-VAVE's V16 file. this step needs V15).
2. Groove OS installs over V15, straight after, as from any stock FM-1. You do not press anything in between.

Tick the list (the same four boxes as an install, one that says you have backed up what you want to keep from the other firmware, and the box that says you understand), press put V15 back, then install, and leave the cable and the tab alone for both steps (about twice the usual time). The page shows the progress of each step, and V15 is confirmed (FM-1_015) before Groove OS is offered to the FM-1.

Careful: putting V15 back replaces the other firmware on your FM-1. Treat anything it saved on the FM-1 (presets, patterns, settings) as lost. If you want to keep something, back it up with that firmware's own tools first: this page does not copy it out.

If it stops part-way, connect again. If the FM-1 waits in its updater while V15 was going on, the page asks for the V15 file again and finishes V15 first, then installs Groove OS. If V15 is already on, the page offers the normal install.

Updating

Updating is the same page: when a newer build is published the button reads install and the page says which version the FM-1 runs now. Your projects are normally untouched. The list before an update has one more box: your projects are exported, or you don't need them. export all right under it saves them all to your downloads and ticks the box for you.

Which build is on my FM-1? The boot screen and ABOUT show the release, 1.4, for 1.4 and for 1.4.1 alike. The Install page tells them apart: once connected it shows the build the FM-1 runs, FM-1_204 for 1.4.1 and FM-1_321 for 1.4. 1.4.1 is the update that makes scenes bring back each track's pattern (see What's new).

If an update moves where projects are stored, the page says so before it writes anything and offers export all first: every project is saved to your downloads as a .groove file, and a file can be put back afterwards from the Projects page (see PROJECT). If the FM-1 runs a build too old to be asked what it holds, the page says the list is not known.

Careful: export your projects before any update that warns about storage, even if you think nothing important is in them. Projects saved in the old storage format do not survive such an update.

Your own sounds come along. An update on this page saves the sounds on your FM-1 in the browser before it starts and puts them back at the end, so your kits are there when the FM-1 restarts (see Your own sounds). If putting them back stops, Your own sounds says at the top how many sounds from before your update are safe in this browser, and Put my sounds back (under Your FM-1) puts them on. An update made any other way leaves the FM-1 without them until you put them on again.

If an install is interrupted

An install can stop: a cable pulled, a tab closed, a computer asleep. The updater is part of the FM-1 and is always there, so it can be finished.

A dark screen after an interrupted install is normal: the updater has no picture. It is waiting, not broken.

If the page stops the same way twice, or the FM-1 shows nothing on USB at all after a power cycle, write to us before trying anything else: we will get it back with you.

The way back to V15

The page can put M-VAVE's original firmware back, V15 or V16, at the bottom, under the way back. Read this part before you use it.

Careful: there is no backup of the stock firmware on the FM-1 or on the page. Going back needs M-VAVE's own file, and it erases your saved Groove projects from the FM-1: M-VAVE's firmware uses the flash where Groove OS keeps them. The page saves them first, to your downloads and in this browser, and when you install Groove OS again from the same browser it puts them back by itself. Export them from the Projects page too if you want your own copy. Installing M-VAVE's firmware the same way is also how you get back from a build you do not want.

You need M-VAVE's FM-1.fwsc, straight from M-VAVE's server, or from M-VAVE's own download page: open its PC Firmware tab, find FM-1, and press Download. M-VAVE offers V16 there since 21 October 2026; V15's file works too, if you kept it. Only M-VAVE's own V15 and V16 files are accepted: the page checks the file, and says so if you choose another (that is not M-VAVE's original firmware file).

1. Export your projects (Projects page), if you want to keep them.
2. Under the way back, choose M-VAVE's FM-1.fwsc in the file box.
3. Tick the list: the same four boxes as an install, the one that says your Groove projects are exported or you don't need them, and the box that says you understand they will be erased.
4. Press go back to M-VAVE's firmware. It runs the same two steps, in about the same time, from any state, including a unit waiting in its updater.
5. When it says back on M-VAVE's V15 (or V16), the FM-1 reports FM-1_015 (or FM-1_016). Groove OS installs again from the same page over either. Installed from the same browser, it puts your projects back in their slots and checks each one. It only fills slots that are empty: if a slot holds another project by then, the page asks before it puts yours there.

Putting V16 on replaces the four preset banks and the FM-1's factory copy of them with V16's own data: the page says so when you choose V16's file. Before the way back from Groove OS the page also reads the factory copy; if V16 damaged it earlier, it tells you that RESET BANK on V15 would bring back empty or garbled banks.

Your own sounds don't come to V15, and V15 stays exactly as it was. They wait in the browser: once Groove OS is back on, Your own sounds puts them back.

If you only want to try the stock interface for a while, you do not need the way back: hold OCT- and OCT+ while switching on, and the FM-1 runs as stock until the next power cycle. See Safe mode.

The simulators

Install and Projects have a demo mode, with ?sim=1 added to the address, that runs the page against a simulated FM-1. Nothing is sent to any device. It is useful to see what the page does before you try it for real.

Last resort: USB download mode

If the FM-1 stays dark after a power cycle, and the Install page cannot see it or cannot finish, there is one more route, used by the developers: JieLi's USB download mode. It rewrites the flash from a computer, without the firmware running, and brought a unit back from a boot loop during development. It needs the project's command-line tools (tools/fm1_enter_uboot.py and tools/fm1_uboot_recover.py, Python 3 with pyusb), a .fwsc package (the Groove OS build, or M-VAVE's V15), and on macOS sudo. docs/FLASHING.md in the project's repository has the full procedure. In outline:

killall MIDIServer; .venv/bin/python tools/fm1_enter_uboot.py
sudo .venv/bin/python tools/fm1_uboot_recover.py --max-sectors 40 FM-1-groove-os.fwsc

The first command asks the FM-1 to reboot into download mode (the tool reports WL80UBOOT1.00). The second writes only the sectors that differ, reads each back, and verifies the whole image. --full allows any number of changed sectors, which going back to V15 needs. If the flasher sits at Waiting for [usb:4c4a:8057], download mode timed out while you typed your password: enter it again and start the flasher straight away.

Careful: download mode needs the firmware to reach USB MIDI, even briefly. Groove OS is built so that nothing of it runs in the first 2.5 seconds, so USB is always up by then.

Troubleshooting