WORM (Write-Once, Read-Many)

Data storage devices (e.g. CD-ROM’s) where the space on the discs can only be written once. The data is permanently stored. This is often today’s primary media for archival information. Common disc sizes run from 5.25” (1.3 gigabytes) to 12” (8 to 10 gigabytes) capacities. There is also a 14’” disc (13 to 15 gigabytes), only manufactured by Kodak’s optical storage group. WORMs can also be configured into jukeboxes. There are various technologies. The expected viable lifetime of a WORM is at least 50 years. Since it’s impossible to change, the government treats it just like paper or microfilm and it is accepted in litigation and other record-keeping applications. On the negative side, there is no current standard for how WORMs are written. The only ISO standard is for the 14” version, manufactured only by one vendor..”