Implementing the universal virtual computer

In order to keep digital objects for an indefinite period of time, one needs a very contrived archiving system. One challenge is to sustain the accessibility of document formats that are becoming obsolete, another is to guarantee their authenticity. The Universal Virtual Computer (UVC) is a simple yet powerful approach to preserve digital objects on a very long-term scale. Its main attraction is that documents do not have to be processed and transformed during their whole archive lifetime. In contrast, when using the migration approach, all documents have to be processed in regular intervals. This is not only time-consuming; also, after a number of migration steps a document's authenticity is seriously threatened. UVC does not share these problems. With UVC, the main effort occurs before ingest time: rendering software for interpreting documents of a given format on UVC must be developed and archived. The effort spent in the development of the rendering software will determine the degree of authenticity. In order to access archived objects, an implementation of UVC must be available. The focus of this paper is on implementing UVC. So far, only proof-of-concept implementations of UVC were available. We have gained practical experience by implementing UVC on different platforms based on a collection of vintage, but still fully working supercomputers. These efforts have led to an improved specification of the UVC, which simplifies implementation even more.