ACROSS THE DECADES - 40 years of data archiving
 

Processing and preservation - media


punch card and paper tape   80-column punched cards and 6-row paper tape. Both generally used in the UKDA for receiving data pre-1990. Punched cards were used as the primary means of data dissemination until around the same time.

magnetic tape   Magnetic Tape. Scotch (Seven inch) (c.1981) and Graham Magnetics (Twelve inch) (c.1979). The left hand tape held 1600 bits per inch, meaning that the whole tape would contain some 40 Megabytes (MB) of data. These tapes were used predominantly for data storage, but some studies would have been deposited at the UKDA with this media.

floppy disk   Floppy Disks. (1) unbranded 5.25" disk used by the UKDA to distribute its Census Data Pack to schools in the mid 1980s. This type of disk was introduced in 1976. (2) 3.5" disk of the type first introduced in 1984; (3) a Zip Disk, first introduced in 1994 and generally considered obsolete by 2003. The UKDA still receives data on this form of media. The first floppy disk was sent out from the UKDA in October 1981.

Optical Disk   Optical disk - usually known as a CD, introduced on the market in late 1982. Not used by UKDA as dissemination media until 1991. In 1993 the ESRC gave a special grant to the UKDA to purchase a " 'writable' compact disk workstation". The cover shows the first bespoke CD published by the UKDA in 1991; the CD on the right was the form in which most data was disseminated until around 2000 when the download service was launched.

magneto-optical discs   Three different magneto-optical disks. Used by Data Archive for backups from the late 1980s. Each holds around 650 MB of data.

Quarter inch cartridge   Quarter inch cartridge. Media offered by a local authority in 2005 as part of a study on access to media. Note the use of detailed file information on the cartridge.

data cartridges   Data cartridges: Sony 8mm data cartridges (left) and Maxell HS8/112 data cartridges (both c.1989). Used for the delivery of 1991 census data. The Sony 8mm data cartridges contained 90 metres of tape with a capacity of 1.3 Gigabytes (GB) of uncompressed data per tape and a read/write speed of 0.6 MB per second. This tape format was superseded by 1993.

sdlt   SDLT (Super Digital Linear Tapes) These magnetic data storage tapes were first developed in the early 1980s. The UKDA currently uses these media as part of its preservation strategy. The most recent of these tapes store 800 GB and can be written at the rate of 60 MB per second.