Ferret

Turns on the hidden dev menu in your OP-1 Field's te-boot - in your browser.

No firmware is read or written, no keys are involved, and nothing is sent to a server. The page talks to the unit's own USB MIDI interface and flips a service flag the bootloader already has.

Dev mode enables options that could be dangerous, don't enable it unless you know what you're doing.

How this works

te-boot (the OP-1 Field's bootloader) has a hidden dev mode. When it is on, the main menu gains its hidden dev entry.

  1. The transport. While the te-boot menu is on screen, the unit offers a USB MIDI interface. te-boot's console commands travel there as the same COBS + CRC-8 te-serial frames the desktop tools use, carried 7-bit packed inside a TE SysEx message: F0 00 20 76 … <packed frame> F7.
  2. The header. The OP-1 Field's packed header is 00 20 76 02 66: te-boot 1000.0.34's MIDI handler compares exactly F0 00 20 76 02 66, and its reply builder emits the same envelope. That differs from the OP-XY's 00 20 76 21 66. The page confirms the header by sending the read-only 0x09 metadata query, and Plan B lets you override it.
  3. The flag. te-boot turns dev mode on when the file bootloader.dev exists - or at runtime through console command 0xAC. This page uses the command, so nothing is flashed.
  4. The challenge. Before acting, 0xAC checks a 16-byte response derived from a value the unit itself reports: command 0x1F returns OTP field 0x13, and the response is that field XOR 99 4A F3 ED. The page reads the field live from your unit and computes the response - no secret is stored on this site. OTP field 0x13 is a per-unit challenge, not the firmware AES key.
  5. No readback, no reply. te-boot has no command that reports dev mode (the flag is only used to render the menu), and 0xAC deliberately sends no reply - so the menu on the unit's screen is the one and only confirmation. The page asks you to read it. A wrong signature is a silent no-op.
  6. Reversible. The disable button sends the same command with the delete op: te-boot deletes bootloader.dev and clears the flag. This page never touches firmware, SPI or the OS partitions.
  7. Local only. There is no server: the page only sends MIDI messages to your unit over USB.
  1. 1ok

    Browser check

    Checking browser support...

  2. 2ok

    Put the OP-1 Field into te-boot

    1. Power the OP-1 Field off.
    2. Hold the COM key while switching it on. The screen shows the te-boot menu.
    3. Connect it to this computer with a USB cable and stay on that menu - the unit's MIDI interface comes up with it.

    Then press the button below: Chrome will ask for MIDI (SysEx) access - click Allow.

  3. 3ok

    Connected unit

    This is what answered the te-boot probe over MIDI.

  4. 4ok

    Enable or disable dev mode

    Check the OP-1 Field screen first: if te-boot already shows its dev entry, dev mode is on - nothing to enable.

    Both buttons read OTP field 0x13 from your unit (command 0x1F), derive the 0xAC response from it, and send the command: Enable writes te-boot's bootloader.dev marker, Disable deletes it.

    Seeing the result: te-boot only redraws its menu when you navigate - after either button, leave the menu and come back to it. The hidden dev entry then appears or disappears. A power cycle keeps it (the marker file persists).

Plan B - manual controls

Every wizard step as an individual button.

MIDI

te-boot

Dev mode

Transport

Reference - exact bytes, no device needed

Live log