Upgrade the Midronome Bootloader

The bootloader is the part of the firmware which takes care of updating the main firmware. This page is for Midronome devices only, with firmware 3.0 and earlier.

All Sim'n Tonic devices now use a new bootloader, much smarter and much faster, and your device needs to upgrade its bootloader for any future firmware updates.

 

Step 1 - Upgrade bootloader

The first step is to upgrade the actual bootloader, which will erase your current firmware. Download and run the "Upgrade Midronome Bootloader Step 1" program, and when the program asks for a file, give it the "upgrade-bootloader.midr" file.

Mac OS Windows
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Run the "Upgrade Midronome Bootloader Step 1" program, follow the instructions on the screen, and when the program asks for a file, give it the "upgrade-bootloader-v99.9.midr" file.

Midronome Bootloader Upgrade Step 1

(the FW version shown on the device will be "99.9" - this is normal)

Note: if it cannot find your Midronome, try closing all applications using MIDI and restarting the program.

Important! The old bootloader:

  1. does not work with macOS Sequoia and newer
  2. has issues with Windows 11 when the recent (March 2026) MIDI updates from Microsoft are installed

If you are in those cases, unfortunately the only way forward is to find another computer (or to roll back the new MIDI updates on Windows)

There is nothing we can do to solve this, as the bootloader needs to run once to update itself. Please note that:

  • Step 1 only requires a USB port and takes a few minutes - it can easily be done on a borrowed or public computer
  • This is an issue for step 1 only - the new bootloader works perfectly fine with any Mac or Windows

 

Step 2 - Load the newest firmware

At the end of Step 1 your device will show "UPG" with a green light, that means the upgrade was successful and you have the new bootloader.

Midronome showing "UPG" with new bootloader

(if the LED is not green, check your USB connection to the computer)

You should now be able to do a normal firmware update using the FW Update Tool from the Support page.

 

Any issues?

If you have any issues or questions during the process, do not hesitate to reach out! You can see the different ways to contact us at the bottom of the Support page.