Abstract: An apparatus for supplying wire to a wire bonding mechanism is presented. Lengths of wire are fed to a low mass wire-loop reservoir while the bonding process is taking place. Wire is then supplied, at a high speed, from the wire-loop reservoir for the next bonding operation. The amount of wire supplied is precisely measured by measuring the change in the amount of wire stored in the reservoir. The apparatus can supply both single lead wire and twin lead wire. When twin lead wire is supplied, the two wires of the twin lead are separated at predetermined points before being fed to the wire-loop reservoir.