5.2.2 PRESERVATION OF ACCESS SOFTWARE LOOK AND FEEL
The second scenario assumes that the Designated Community wishes to maintain the original ‘look and feel’ of the Content Information of a set of AIUs as presented by a specified application or set of applications (CDO specific software). Conceptually, the OAIS provides an environment that allows the Consumer to view the AIUs Content Information through the application’s transformation and presentation capabilities. For example, there may be a desire to use a particular application that extracts data from an ISO 9660 CD-ROM and presents it as a multi-spectral image. This application runs under a particular operating system, requires a set of control information, requires use of a CD-ROM reading device, and presents the information to driver software for a particular display device. In some cases this application may be so pervasive that all members of the Designated Community have access to the environment and the OAIS merely designates the Content Data Object to be the bit string used by the application. Alternatively, an OAIS may supply such an environment, including the Access Software application, when the environment is less readily available. However, as the OAIS and/or the Designated Community moves to new computing environments, at some point the application will cease to function or will function incorrectly.
The OAIS response to preserving an Access Software application would likely depend, in large part, on whether or not it had or could obtain the source code for the Access Software. Subsection 184.108.40.206 discusses proven methodologies for preserving application access across changes in technology. The major factors in the use of these techniques would be the cost/benefit ratio to the OAIS and the associated Designated Community. If source code or commercial bridges are not available and there is an absolute requirement for the OAIS to preserve the Access look and feel, the OAIS would have to pursue ‘emulation’ technology that is currently being researched in the Digital Library domain. This technology is discussed briefly in 220.127.116.11.