How Claude's Fable Model Saved My Gear and Got Me Excited About Playing Guitar Again
We all have that one piece of gear. Mine was a Behringer FCB1010, a two-foot slab of MIDI pedalboard that has followed me through three apartments and never actually worked. Not once, not properly. Every couple of years I'd drag it out, lose an evening to MIDI menus, get maybe two switches doing something useful, and put it back under the desk to collect dust and silently judge me.
Not my room, but this is exactly what the setup looks like: guitar, hope, and ten switches that do the wrong thing. (photo: Scuffham Amps forum)
The dream was always simple: stomp a switch, get the Comfortably Numb solo tone. Stomp another, Purple Rain cleans. Rock the expression pedal, wah. And the real dream, the one that kept me dragging this thing back out: playing my Iron Maiden repertoire properly. Seventh Son harmonies, The Wicker Man gallop, both Murray and Smith parts coming out of one guitar, hands never leaving the strings. The reality was a pedalboard from 2004 and an amp sim from this decade, BIAS FX 2, that flatly refuse to understand each other out of the box.
Skill issues? Sure. But gosh, are these two complicated to wire together.
Why everyone gives up on the FCB1010
Hey FCB1010, we need to talk.
Ten switches, two expression pedals, one two-digit display, infinite menu-diving. (photo: Sweetwater)
Press one switch on a factory-fresh FCB1010 and it doesn't send a MIDI message. It sends seven : five Program Changes and two Control Changes, on multiple channels, all at once. BIAS FX 2's MIDI Learn dutifully grabs whichever of the seven arrives first. Congratulations: your delay toggle is now mapped to garbage.
The official fix is programming each footswitch from the front panel. The procedure involves holding the DOWN pedal for exactly 2.5 seconds, navigating menus rendered on a two-digit LED display, entering numbers by stepping on footswitches (10 means zero, obviously), and confirming with UP. Per value. Per slot. Per preset. My layout needed 26 presets. I did the math on that foot-dance and understood why this thing lived under the desk.
SysEx, my old friend
But the FCB1010's entire brain is 2,352 bytes. One SysEx dump. The format was reverse-engineered years ago, and there's a lovely little MIT-licensed Python library (riban-bw/fcb1010) that encodes and decodes the whole memory.
Which means the entire pedalboard can be described as data:
SONGS = [<br>(0, 1, 0, "Comfortably Numb"),<br>(0, 2, 1, "Purple Rain"),<br>...<br>(2, 1, 10, "Iron Maiden"),<br>TOGGLES = [<br>(6, 20, "Wah on/off"),<br>(7, 21, "Octaver/Harmonizer"),<br>(8, 22, "Delay"),<br>(9, 23, "Distortion/Boost"),<br>(10, 24, "Tuner"),
Edit the table, run uv run rig.py send, done. No foot-dance. The script round-trips the generated dump through the decoder before it ever touches hardware, so a typo can't brick anything.
Getting the upload to actually land taught me three things the manual buries:
In global config mode you tap UP to change pages. Holding it does nothing. I held it for a very long time.
After the transfer, you must hold DOWN to save. Skip it and the pedal politely discards everything. I skipped it. Twice.
Cheap USB-MIDI cables are pathological liars. Mine passes normal 3-byte MIDI perfectly, then silently eats SysEx, and only in one direction. Pedal-to-Mac dumps vanish into the void; Mac-to-pedal uploads work fine. I spent a whole evening blaming my own code before a packet capture pointed at the cable. A MIDI monitor showing traffic proves nothing about SysEx. The only real test is counting bytes.
BIAS FX 2 has no API. It has something better.
You might be thinking: "Okay, so the pedal side is code now. But BIAS FX 2 has no scripting interface, no import format, no automation story at all. Now what?" I'm glad you asked. What BIAS FX 2 does have is a data directory full of plain JSON, and nobody stopping you from reading it.
A few evenings of spelunking later, the whole map:
midi.json: global mappings. Maps Program Change numbers to preset UUIDs, plus app-level actions like the tuner (utility.tuner).
GlobalPresets//preset.json: the bank's index. Fun fact: a preset folder that isn't listed here does not exist as far as the app is concerned. Found that one the hard way.
GlobalPresets///data.json: the full signal chain, every pedal with a stable UUID.
GlobalPresets///midi.json: per-pedal CC wiring, referencing those UUIDs.
The scary part was signal-chain surgery. Confession: in all the years I've owned this pedalboard, I have never , not once, had the wah pedal, octaver, volume pedal, and tuner all working from the floor at the same time. That was the whole dream, and it died in MIDI Learn purgatory every single attempt. This time I wanted all four in every preset, and I was not going to click through fifteen presets to add them. Editing a 340KB JSON file with embedded scene state sounds like a great way to corrupt your tone library. Then you notice that scene...