Emulation involves recreating the behaviour of old hardware environments on a current computer, which enables obsolete software to be installed and run. Unlike migration, emulation does not involve changing the obsolete digital object. Instead, it allows the digital object to be accessed using the software originally used to create it.
Emulation has become a prominent digital preservation method among collecting organisations, such as archives, museums and libraries, who regularly acquire obsolete digital objects that can no longer be opened using current technologies.
While emulation may be of interest to some Australian Government agencies who create complex digital objects in non-standard formats, it is not as feasible for the bulk of government information. This can be more easily preserved using well-established preservation strategies such as bit preservation and migration.
A recent National Archives project, Building Emulation Capability, examined the feasibility of emulation techniques for enabling access to a number of obsolete digital objects in its own collection. This work was undertaken with Emulation-as-a-Service Infrastructure (EaaSI), a collaborative project run by Yale University. Several of the project’s findings have implications for the uptake of emulation by other agencies as a preservation method:
- Externally hosted emulation has the potential to reduce costs and provide greater support for agencies interested in using emulation technology. However, the business model is not well established, and the ongoing costs and support arrangements are as yet unknown.
- Cybersecurity issues need to be identified and mitigated for both externally-hosted and stand-alone instances of EaaS.
- It is unlikely that emulation could be used for all types of information assets.
- Copyright law can present challenges to the sharing of emulated environments, depending on the exceptions that apply to an agency.
- It may be difficult to maintain the necessary equipment and skilled staff to use emulation if it is not part of an agency’s regular business.
- Emulation (and preservation more broadly) is reliant on good metadata. Format is specified as an ‘additional’ property in the Minimum Metadata Set for higher value and longer-term business information. However, this may not include data about the software or operating system used to create a record, making emulation more challenging.
Want to know more?
The National Archives will continue to monitor developments in emulation technologies and provide further advice as it becomes available. Australian Government agencies who are interested in using emulation as a preservation strategy should contact the Agency Service Centre for more information.
Read Preserving information for advice about preserving Australian Government records and preservation planning more broadly.