Technical obsolescence

IBM pc from 1981.
Image: Rune's Computer Museum

Huge sums of money are being invested in programs of digitisation. Yet rapid technological evolution means rapid obsolescence. It is common experience that we can scarcely read text files more than a few years old, let alone access complex databases. Both software - database management systems - and hardware - the machines on which they run - evolve. The result can be that large scale digital assets become obsolescent along with the machines on which they were born and used.

There are already numerous examples of this, one of the most striking being the BBC's Domesday videodisk. The BBC commemorated the thousandth anniversity of the compilation of the Domesday Book itself by commissioning records of every parish in England from local schools. Only fifteen years after they were made, few disks survive, and the database is having to be completely reformatted and remade.

What to do?

First, distinguish between the means of accessing and presenting the digital assets and the digital assets - the data - themselves. The principles used to ensure interoperability across different organisations' systems are the same as those that will ensure longevity for digital assets - open source software, internationally recognised standard formats for images, text, sound and other media.

On maintaining the data in usable form, there are two main schools of thought. Some people say that it is easier to emulate the software that ran the original files so that it works on new machines:

Other people say that it is better to convert the digital asset into a new file format that newer software can run:

Migration preserves the information content of the digital asset but does not necessarily result in an exact digital replica, nor in the original features of display and appearance.

Many people say that the vital thing is to keep using the digital asset. In that way small upgrades or adjustments are made that ensure it remains usable. Any of these solutions, however, raise issues of authenticity.