Before revision: The concept was pioneered by Adrian Thompson at the University of Sussex, England, who in 1996 evolved a tone discriminator using fewer than 40 programmable logic gates and no clock signal in a FPGA .
After revision: The concept was pioneered by Adrian Thompson at the University of Sussex, England, who in 1996 used an FPGA to evolve a tone discriminator that used fewer than 40 programmable logic gates , and had no clock signal .