An on-line backing store system capable of storing larger
quantities of data (sometimes an order of magnitude more) than conventional
backing store. The quoted capacity of mass storage has increased with advances
in technology: in the early 1960s a megabyte of storage came in this category;
in the early 1980s
the term applies to devices such as the IBM 3850 automated tape library that can
store up to 472 billion bytes (gigabytes) of data.