IBM Corp says that scientists at its Almaden Research Center in San Jose, California have perfected a technique for etching the magnetic tracks onto a hard disk platter to such good effect that a 3.5 disk using the medium could store 1.25Gb. The tracks on the disk are just half a micro wide. The company is clearly a long way from bringing the technology to market in a product – in particular, there is no indication that it has cracked the problem of designing and fabricating a head that could read and record the ultra-fine tracks, but the announcement is being hailed as evidence that magnetic recording will survive the threat from optical storage much longer than most observers expected.