E. Storage of Digital Files

The Denver Public Library stores its archive files onto Mitsui Gold  CD-ROMs.  Two copies of each archive disk are made.  To date, we have not experienced any problems with the CDs.  Other institutions, however, have had problems that warrant concern and further research. The problems encountered are not related to the integrity of the digital information but the quality of the media itself.   Errors during production of the CDs or atmospheric storage conditions may be at fault.  In order to ensure the long-term usefulness of the digital information, some institutions advocate archiving the CDs to digital tape, in essence making an archive of the archive file.

The Library’s initial plan was to transfer the archive files to the best available storage media after 10 years.  As we approach this date, we have discovered that the issue may be more complicated.  Transfer of the complete collection of archive files will be time consuming and costly.  Without an effective way to test the integrity of the current CD, we will not know if we are transferring degraded information or not.  Ideally, CDs could be tested upon creation to establish that quality standards have been met.  Random testing of CDs during their life would assist institutions in determining when the digital information should be transferred. 

Compressed files for use on the web site and Intranet are stored on two servers:

RAID - Nstor 8LE 8-bay image server (upgradable from current 110 Gig capacity)

Sun 450E server (web site)

F. Scanning and Printing Color Material

Since 2001, the Library has begun to scan a large number of its items in color.  This includes photographic prints that have a sepia tone, hand-colored materials, and original artwork.  In addition, as we made copies of items in the collection for customers, it soon became clear that we needed to come up with a system to provide accurate color reproduction in a cost-effective manner. 

The color management process at a universal level is very new and is still emerging. Through research and testing the Denver Public Library has decided on hardware, software and a format for handling the unique color artifacts in its collection.