> A later version of the delay line used metal wires as the storage medium. Transducers were built by applying the magnetostrictive effect; small pieces of a ma

> A later version of the delay line used metal wires as the storage medium. Transducers were built by applying the magnetostrictive effect; small pieces of a magnetostrictive material, typically nickel, were attached to either side of the end of the wire, inside an electromagnet. When bits from the computer entered the magnets the nickel would contract or expand (based on the polarity) and twist the end of the wire. The resulting torsional wave would then move down the wire just as the sound wave did down the mercury column. In most cases the entire wire was made of the same material. wow. this is literally a sound wave. i thought it was some kind of euphemism. as i was until now only familiar with the electric variety.