METHOD OF AND APPARATUS FOR DIGITAL DATA STORAGE

摘要

Digital data storage conventionally requires an election to be made between retaining data on-line, which consumes expensive media, or moving it to a far cheaper archive medium, which is relatively inaccessible. This specification discloses a hybrid arrangement in which all material is retained on-line, but is progressively degraded as it becomes less useful, with off-line storage of the source material. On-line browsing of an entire library remains possible, but without incurring the expense of maintaining the entire library at source quality on-line.