This is the firmware itself, compiled to WebAssembly from the same sources as the device build: the screens, the sequencer, the 128 GM sounds and the drum kit. Songs you save stay in this browser's flash.
| Knobs | Drag up and down, scroll, or focus one and use the arrow keys. MASTER is the volume |
| Keys | Z…/ is F3 to A4 with the black keys on the row above, W…U goes on to G5 |
| PLAY | Space |
| Hold | Hold a button with the mouse as long as the manual says: SEL twice for a new song, ARP for 1 s to erase a track |
The panel is laid out like the FM-1's. The manual is in the README.
Connect the FM-1 with a USB data cable, then let this page use MIDI. Chrome, Edge and Opera on a computer can do this; Safari cannot.
Tested on a real FM-1 by the author. It is provided as is, with no warranty of any kind: you install it at your own risk, and the author is not responsible for a bricked or damaged device or lost data (see the disclaimer and the GPL-3.0, sections 15 and 16). Know the recovery steps before you install.