<hardware> An informal generic term for floating-head
magnetic disk drives in which the read-write head planes
over the disk surface on an air cushion.
The name arose because the original 1973 engineering prototype
for what later became the IBM 3340 featured two 30-megabyte
volumes; 30--30 became "Winchester" when somebody noticed the
similarity to the common term for a famous Winchester rifle
(in the latter, the first 30 referred to caliber and the
second to the grain weight of the charge).
