Converting tapes to CDR

1
Converting tapes to CD-R

• By
• Jan Danielsen
• IT-manager and Special Consultant
• Danish State Archives, IT department

2
The collection of electronic archives

• 2094 3/4 inch tapes dating from 1972 to 1998
• 2600 CD-R dating from 1997 -
• Both in 2 copies kept in different locations

3
Process of conversion
Recover missing data in Norway
Read all tapes
Tapes from one copy
Join the two datasets
Recovered data
Most data
Data
Join the two datasets
Join the two datasets
Data
More data
Read tapes not successfully read
Recover missing data in USA
Recovered data
Current stage
Tapes from the other copy
4
Physical errors on tape
Reasons The tape was stored under the wrong
conditions. The tape was earlier used for to
store other data. The tape was originally of a
bad quality. The machines used to read it was set
up wrong.
5
Correction
Merging tool
Tape one
Tape two
Recovered data
Read data from the other tape. If there are
errors on the other tape use the merging tool to
merge the recovered data from the two tapes
6
Lessons learned

• The input quality of new media in the collection
  must be controlled more thoroughly.
• There must be testable quality criteria for the
  media in the collection
• The collection must be monitored and tested more
  frequently than earlier.
• The storage conditions must be controlled
  regularly

7
Actions taken

• We changed the strategy for receiving and storing
  archives
• We burn the copies for long time storage purposes
• We keep data on to different types of media (CD-R
  and Disk RAID)
• We increased the activities already in action
• The CD-Rs are frequently tested according to a
  test plan.
• The storage conditions are monitored.

8
Physical error on CD-R
Reasons There was an error in the production of
the CD-R.
9
Handling

• Correction
• Reburn all CD-Rs from this production series.
• Lessons learned
• The output of any process must always be fully
  tested.
• Actions taken
• We bought and rebuilt a CD copier. So that we in
  the same process could Copy, print and test all
  CDs produced in the Danish State Archives.

10
The next steps

• Data conversion of the collection
• EBCDIC to ISO 8859-1
• Hierarchical data structures to Relational
  structures or XML.
• Paper documentation to XML metadata and other
  electronic documentation.