A mathematical chaos circuit invented by Rob Hordijk; it is at the heart of his Benjolin aleatoric instrument. The circuit consists of a shift register and a basic 3-bit D/A converter. An external VCO is fed as the input to the shift register (the input is taken to be a '1' or a '0' bit depending on if the VCO output is positive or negative), and a second external VCO is used to clock the shift register. Three bits output by the shift register are fed to the A/D converter, which produces an 8-level control voltage signal which is fed back to the VCOs. This causes the VCOs to exhibit behavior which seems to have a pattern but never repeats exactly. Hordijk calls the circuit "bent by design", a reference to circuit bending.