Preservation of Historical Records (1986) / Chapter Skim
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7. Optical Disks
7. Optical Disks
Pages 71-78
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From page 71... ...
The most positive statement about archival life is that there exists a general belief that many forms of optical disk media will retain data for 10 to 20 years. A look at the natural progression of data systems of recent technology indicates that the useful system life is only about 10 to 20 years.
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From page 72... ...
Of these possibilities, 10 to 20 working write-once systems have been built; TABLE 7-1 Applications Formats for Optical Disk Read or Write Data Format Common Names Read only Analog video Videodisk Read only Analog data Digital videodisk Read only Digital audio Compact disk (CD) Read only Digital data Compact disk read only memory {CD ROM)
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From page 73... ...
The industry has made attempts to start the standards process, as shown by the workshop held in June 1983 on Standardization Issues for Optical Digital Data Disk Technology National Bureau of Standards/National Security Agency, 1983~. In addition, the American National Standards Institute ANSI)
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From page 74... ...
Only peripheral considerations will be given to the archival qualities of the optical disk. TABLE 7-3 Examples of Typical Digital Data Storage Systems System Time Bits IBM Harvest Tractor Tape System 1962-1976 3 x 10~' IBM Photo Digital Store 1970-1972 2 x 10~2 Ampex Terrabit Memory (TBM)
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From page 75... ...
3. The data require recopying at least every 20 years.
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Digest of Papers From the Sixth IEEE Symposium on Mass Storage Systems, June 4-7. National Bureau of Standards/National Security Agency.
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OPTICAL DISKS Microfilm reading room at the NationaJArchives. Researchers use microfilm records in lieu of original documents.
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From page 78... ...
Researcher examining diocument at the National Archives. Condition of the document illustrates the need forpreservation.
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