Archive for the ‘Technologies’ Category

Preservation Approaches to Technological Obsolescence

March 22, 2006

At 9am sharp we went straight into issues surrounding the obsolescence of digital file formats and their supporting digital hardware and software. What better way to begin the day!

Generally there are three or four ways of dealing with this:

Migration: Changing a file from one format to another. i.e. Word 2.0 file to Word XP file. Migration changes the data but hopefully in a way which retains the integrity of the digital object.

Things to consider might be whether the new format can still represent the ‘significant properties’ of the original format. Can the migration be done automatically? How long will it take (and therefore how much will it cost?). On what basis is the new format chosen? How do we know the migration is 100% successful?

Refreshing: Moving files from one storage media to another. i.e. moving a document from a 5″ floppy disk to a networked server. The object remains unchanged.

Emulation: Writing software that runs on a modern Operating System which emulates the software environment of the original creator application. i.e. writing a Spectrum ZX81 emulator to run my favourite game of all time: ‘Elite’.

Preservation of hardware and software: Basically, you keep a museum of old computers with the original software running on them.

Each approach can be useful depending on the circumstances, although emulation and the museum approach are generally regarded as the most inconvenient. Archives aren’t museums and approaching preservation this way is contrary to the digital archival process which is to move conservatively with changing technology rather than hang on to it.

Software emulation is invaluable some of the time, but may be expensive to undertake because of the development resources required and often a black art in reverse engineering as older technologies tend to be poorly specified or the programing skills required are, like many skills, lost over generations as technology moves on. Also, if you emulate the original software faithfully, then you get the older, more difficult interfaces that came with it. For a large collection of a single file format, a single emulator might be a useful method of access to multiple objects. It also helps retain our understanding of older systems. The BBC Doomsday Project is a good example of when emulation was the most successful method of bringing the data back to life.

In most situations though, migration of file formats and refreshing of storage media are what most archivists rely on. At the IS, for example, we already undertake these approaches, migrating paper to microfilm, WordPerfect files to Word files or PDF, and by incrementally upgrading our hardware and software environments. I think it would be useful if ITP and IRP discuss a joint strategy for this, recognising that traditional IT migration strategies do not always recognise the archivist’s needs and expectations. Digital Archiving is part of both the IT world and Archiving world and our digital preservation requirements need to be reflected in a joint ITP and IRP agreement. Already AVR are starting to feel the need for this as we archive 200GB of images on IT’s servers and require 1TB/year for the storage of video. The storage of this data is not static but requires continual backup, migration and refreshing over time and clearly the two departments need to acknowledge this formally and make resources available.

The next session followed on from this, discussing how Archivists might live with obsolescence. I was hoping for personal spiritual guidance but instead we discussed particular examples where the above approaches might be useful.

I won’t go into detail here, but predictably enough, it focused on the need to develop organisational strategies, promoting the need to analyse and evaluate the collections, create inventories, determine preferred file formats and storage media, assess how market conditions affect the longevity of IT systems, adopt metadata standards, work with IT departments on joint strategies (as per above), watch technological changes and developments (actually write this into someone’s role responsibilities), and be prepared for hard work and headaches.