storage: A way of optimizing the efficiency of a hard drive by spreading out chunks of data so that as it spins (very fast, you know) the computer can absorb (or dispense) the information in a continuous stream. Remember that disks are divided into tracks, and each track is divided into sectors. With a slower machine like the Mac Plus, the data is interleaved at a 3:1 ratio, that is, written to every third sector on the disk. If it were written to contiguous sectors, the hard disk would have to go around an extra complete revolution after each sector was accessed because the machine wouldn't be ready for the next sector. There is just enough time if the drive lets two sectors go by, so the 3:1 interleave is set by the driver software. Older SE's need a 2:1 interleave. Newer Macs are fast enough to use a 1:1 interleave, which is really no interleave at all