draft: false
Name: BlackBox
short-description: A sealed system of audio, voltages and pulses, freshly generated by each press of Z. Vary its inputs and observe its outputs to learn what it does.
summary: |
  *It is not necessary to enter the black box to understand the nature of the function it
  performs.* (Stafford Beer)

  Each time Z is pressed, the card builds a new system: voices,
  voltages, rhythms and the connections between them. Its workings stay sealed. What remains open are its inputs, its outputs and its behaviour. Vary an input, observe what changes, and repeat until the behaviour makes sense. Each system is unique and impermanent; press Z again and there is a new one to understand.
Language: C++ (Arduino-Pico + ComputerCard)
Creator: James Saunders
Version: "0.9.0"
Status: Beta
date-created: 2026-09-27
date-updated: 2026-09-27
tags:
  - generative
  - synthesizer
  - sequencer
  - random
  - cybernetics
  - experimental

contact:
  email: jamessaundersalloneword@gmail.com
  website: https://www.james-saunders.com

panel:
  inputs:
    - id: AudioIn1
      name: Audio In
      type: audio
      description: Always acts on sound. Depending on the patch it is processed by an effect, excites a plucked string, ring-modulates or gates a voice, drives an envelope follower, or secretly modulates a parameter by its loudness. Unplugged, the patch uses internal sources instead.
    - id: AudioIn2
      name: Audio In
      type: audio
      description: As Audio In 1, with its own independent role.
    - id: CVIn1
      name: CV In
      type: cv
      description: Bends one or two internal settings, like a voltage-controlled knob. Can reach voices, CV and rhythm generators, or tempo. Does nothing when unplugged.
    - id: CVIn2
      name: CV In
      type: cv
      description: As CV In 1, with its own destinations.
    - id: PulseIn1
      name: Pulse In
      type: pulse
      description: Each rising edge does one job, chosen per patch. It may replace the internal clock (most often on this jack), or reset, trigger, reroll or sample-and-hold part of the patch. Does nothing when unplugged.
    - id: PulseIn2
      name: Pulse In
      type: pulse
      description: As Pulse In 1. Occasionally the clock input, more often a reset, trigger, reroll or sample-and-hold.
  outputs:
    - id: AudioOut1
      name: Voice / Effect 1
      type: audio
      description: One of a synth voice, FM, plucked string, filtered noise, bytebeat, wavefolder, granular, tape delay or ring modulator. Drone or rhythmic. Level is set automatically when the patch is built.
    - id: AudioOut2
      name: Voice / Effect 2
      type: audio
      description: A second, independent choice from the same set. Sometimes it processes Voice 1.
    - id: CVOut1
      name: CV Generator 1
      type: cv
      description: One of a step sequencer or Turing machine (quantised to the patch's scale, calibrated 1V/oct), LFO, smooth random, Lorenz chaos, envelope, or envelope follower. Often plays the same melody as one of the voices.
    - id: CVOut2
      name: CV Generator 2
      type: cv
      description: A second, independent CV generator from the same set.
    - id: PulseOut1
      name: Rhythm 1
      type: pulse
      description: One of a clock divider, Euclidean pattern, probability gate, burst generator, comparator, or additive grouping (such as 3+3+2). Often secretly triggers a voice or sequence too.
    - id: PulseOut2
      name: Rhythm 2
      type: pulse
      description: A second rhythm generator, steered toward a different clock from Rhythm 1 so the two pull against each other.

controls:
  switch:
    middle:
      name: Play
      description: Normal running.
    up:
      name: Play (reserved)
      description: Same as middle. Reserved for saving patches in a future version.
    down:
      name: Mutate
      description: Hold for about 0.6 s to mutate the current system. It keeps its character, with 2–3 things changed (a resting point, an internal connection, the scale, the tempo, a sequence or waveform).
    tap:
      name: New Patch
      description: Briefly press and release to discard the current system and build a new one. About half a second of measuring, then it fades in. The old patch is gone for good.
  knobs:
    - main:
        name: Variable 1
        description: Moves internal settings on two of the six outputs, sometimes plus tempo. No effect at 12 o'clock, so start there and sweep both ways.
      x:
        name: Variable 2
        description: Moves internal settings on two other outputs, sometimes plus tempo. Neutral at 12 o'clock.
      y:
        name: Variable 3
        description: Moves internal settings on the remaining two outputs, sometimes plus tempo. Neutral at 12 o'clock. Between them the three knobs always reach every output.
  leds:
    - display: list
      items:
        - id: LED0
          name: Audio 1 level
          description: Brightness follows the level of Audio Out 1.
        - id: LED1
          name: Audio 2 level
          description: Brightness follows the level of Audio Out 2.
        - id: LED2
          name: CV 1 voltage
          description: Off at about -5 V, half at 0 V, full at about +5 V.
        - id: LED3
          name: CV 2 voltage
          description: As LED 2, for CV Out 2.
        - id: LED4
          name: Rhythm 1
          description: Flashes on each pulse from Pulse Out 1.
        - id: LED5
          name: Rhythm 2
          description: Flashes on each pulse from Pulse Out 2.