218e Rewired
Custom firmware builder
for the Buchla 218e V3
RSS
⚠ READ THIS BEFORE YOU FLASH ANYTHING
This firmware is for the Buchla 218e V3 only. It won’t work on the 218, the 218r, the 218e V1 or V2, or any other touchplate controller.
Using this tool and firmware is entirely at your own risk. This is an experimental, unofficial firmware, not made or supported by Buchla. Flashing it will probably void your warranty. Recovering a bricked unit may need JTAG hardware and opening the instrument, or may not be possible at all.
A failed flash usually leaves the keyboard in DFU mode, where the flasher can try again, but there is no guarantee that it will succeed. If losing the use of your 218e would be a problem, stop here and keep the factory firmware.
1 · Upload the factory firmware
Supply the stock 218e V3 v36.9 image. You can get it from the official flashing kit.
buchla.com/firmwarefiles/218ev3-Firmware-Flashing.zip
or click to choose
Already running Rewired ?
Load your settings via MIDI to start from them.
Safari needs the Web MIDI extension for this: Get Web MIDI for Safari. If it’s installed, turn it on and allow it on this site.
2 · Select your options
Arpeggiator
Trigger patterns on knob 2
Step sequencer
How to use the sequencer
Control the sequencer by holding pad 4 for one second and tapping an option
Controls while recording (hold for 1 second)
Pressure
Transposition
Keyboard scaling
The lowest key will output 0.3V.
The page plays each note into the keyboard over MIDI, listens to your 208, and fills in every offset below. This needs the keyboard to be running Rewired 3+. It works in Chrome, Edge and Firefox, and in Safari with the Web MIDI extension.
How to measure your 208. Read this first!
1. Set the volts per octave. Match the setting above to how your 208 is trimmed, and leave it there. A table measured at one scaling is wrong at the other.
2. Warm it up for at least 30 minutes. The oscillator drifts as it comes up to temperature, often by more than the error you are correcting.
3. Tune the 208 with the keyboard off: every note is tuned from its 0 V pitch.
4. Patch the 208 into an audio input and set it droning: a steady tone, no envelope, nothing else modulating its pitch. Pick the channel it arrives on.
5. Measure, then send the settings or flash to keep the table, and save it.
Safari needs the Web MIDI extension for this: Get Web MIDI for Safari. If it’s installed, turn it on and allow it on this site.
Offsets for the 65 playable notes
What each note played, in cents.
Positive for sharp, negative for flat. The sweep fills these in. Scroll for the full range
Alternate tunings
Three custom Scala tuning tables, switchable from edit mode.
How to build and switch tunings
Use the Scale Workshop to build scales in the browser and export .scl files.
A file on its own needs twelve degrees, one per key. Add a .kbm keyboard mapping to a slot and it can have any number, repeating at whatever interval it declares — the octave controls step that interval. Empty slots keep the factory temperament.
A scale that repeats at the octave is shifted to make A sit at the same pitch in every slot, so switching tuning doesn’t need retuning. Which degree lands on the bottom C is up to the file: a scale published rooted on A needs rotating first. (Modify scale → Rotate mode in Scale Workshop) A scale that repeats at anything else is left where it is, with its first degree on the bottom key.
To switch between tunings, go into Edit mode and toggle key 27 or 28. The current tuning will be indicated by the rem en and trn LEDs.
3 · Flash it
Install or update
- Download and extract the built package for your operating system.
- Connect the 218e via USB and power it on.
- Run the flasher and follow the instructions:
macOS: double-click 218e Rewired Flasher.app
Windows: double-click 218e_Rewired_Flasher.bat
Windows might warn you about unsigned software
If you get a Windows Defender prompt about the .bat: Click More info → Run anyway.
The first flash pauses for a driver
After the keyboard goes into DFU mode for the first time,
the flasher should open Zadig. Do the following steps in it:- Options → List All Devices
- Select AT32UC3B DFU
- Set the right-hand box to WinUSB, press the Install Driver or Replace Driver button
- Close Zadig.
Oh no… something went wrong
- The keyboard is unresponsive and some LEDs are lit
- The keyboard is probably in DFU mode. Run the flasher again. If that doesn’t work, power cycle the keyboard. You can bring it back without flashing anything by choosing Get the keyboard out of DFU mode when the flasher opens.
- Every LED is lit and nothing responds
- There is no valid firmware on the keyboard: the erase finished and the write did not. Run the flasher again. The instrument stays in DFU for exactly this reason.
- The flasher can’t put the keyboard into DFU mode
- Power cycle the keyboard and try again. If it still won’t go, open Audio MIDI Setup on a Mac (Window → Show MIDI Studio) and check the keyboard is listed there and not greyed out: a stale port looks fine to a DAW and still swallows the request. Try a different USB port, rebooting your computer, or running the flasher from a different computer.
- Windows: the flasher says no device present, or AT32UC3B DFU sits under Other devices
- WinUSB is not bound to the DFU device. Run Zadig as above. Once it is right, the entry moves to Universal Serial Bus devices.
- Windows: the 218e sits under Universal Serial Bus devices instead of Sound, video and game controllers
- Windows picked the wrong MIDI driver, so the request to enter DFU never reaches the instrument. Right-click it, Update driver, choose manually, and pick USB Audio Device.