Translated by Sandrina Khaled und David Hauptmann

In April 2012 two messy, partially defective, and obviously ancient tower-PCs from the estate of Friedrich Kittler (1943-2011) found their way to the group of Scientific Data Processing of the German Literature Archive Marbach (DLA). A challenging process began: to explore and map Kittler’s computers and data storage devices, to identify predecessors and actual systems as well as to separate important from unimportant data. Figure 1 displays the ongoing attempt to obtain an overview of Kittler’s PCs and data. With the help of his former collaborators and his heiress Susanne Holl, it soon became obvious that this estate will exceed the DLA’s inventory of born-digital items of the last ten years as well as the workflows developed to handle them.

Starting with Thomas Strittmatter’s Atari and Macintosh disks in 2003, the DLA developed and established a workflow for preserving and indexing digital personal archives. This worked well with static textual material of manageable size. Until 2013, 281 volumes (mostly floppy disks) from 35 personal archives with 26,700 original files were saved and converted into stable file formats [Bülow 2011]. Almost from the beginning, the DLA adopted a strategy highly recommended by the BitCurator project, that is to file media volumes as a one-to-one copy in sector images [Lee 2013, 27]. In general, sector images are most qualified to preserve technical metadata of file systems (update time stamps, user information etc.) and can moreover be directly integrated as logical drives (read-only) in virtual machines or emulators.

A full-scale comparison of the amount of volumes reveals that Kittler’s media (floppies, CD-Rs etc., original hard drives, further non-original transport media and file collections) outnumber the former digital inventory (‘D-Archive 1.0’) from the last ten years by a significant margin (Figure 2).

The contrast becomes even more apparent in a numerical comparison on the file level (Figure 3). While it is safe to say that most of 1.7 million files are not Kittler’s but commercial or free software (ranging from operating system software to special shareware), there is no safe way to automatically detect irrelevant ones and simply leave them apart. This is due to the special complexity of the estate.

Friedrich Kittler bequeathed texts, images, videos, and artifacts of his programming. The latter comprise source code (written in several programming languages) as well as modifications of his hardware configurations. In approximately 30 years this work was executed under different operating systems, starting with MS-DOS, followed by Unix. From approximately 2000 onwards he worked under Gentoo Linux, not as a normal user with limited system rights, but as root. His standard working directory was not the common /home, he was using /usr/ich instead.

The possibility to encounter Kittler’s files and source code everywhere made it necessary to show utmost restraint in the exclusion of suggested system directories. Furthermore, it is obvious for Kittler’s code that the respective programming environments are of relevance. Therefore, all files from hard drives and most of the readable disks and optical media were examined. Only obvious mass products (such as CD-R free samples enclosed in the magazine c’t) were listed, but not copied. Consequently, a manual selection and conversion as it was carried out in the previous workflow would not work. Not only the amount, but also the specific complexity made evident that this was a special challenge to cope with, from which future estates might benefit.

In July 2012 a group of experts discussed how to approach Kittler’s digital estate. Jürgen Enge and Tabea Lurk proposed to examine the untapped data inventory by a full text index for further processing steps. In September 2012 Jürgen Enge presented a prototype working with sample data. In April 2013 substantial partitions and storage devices were analyzed and made available as image copies from which a representative selection was indexed. Since August 2013 “Ironmaiden” (as the package was called in jest[1]) was consolidated in a virtual machine on the DLA’s servers. It was then further developed and eventually confronted with the whole relevant data inventory.

Before the actual ingest of data into the Indexer, the preparation process consisted of sector-copying, restoring, and listing. Thereby some practical insights emerged that helped to further develop the workflow at the DLA.

At this point, preceding its functions as a full text indexing and MIME type analysis tool, the Indexer also serves as a document server which preserves the authentic path information and overcomes the described restrictions of the file systems (for instance through the structuring of its own finely balanced cache).[3] Likewise, MS-DOS viruses do not interfere with the analysis under Linux.

The Indexer requires general IT knowledge. The particular components derive from the open-source domain. This allows for the software tool to be available online soon. Because the initial recognition and the identification cascade are CPU-intensive, certain computer benchmarks should be upheld. The following components are necessary for the basic operations of the server system:

And the following libraries/frameworks

The necessary performance capability of the system depends primarily on the amount of data to be indexed. To run a quickly responding web frontend, it is useful to execute the SOLR-index on a server system with sufficient RAM.

In summer 2014 two additional old Kittler laptops and 300 5.25” disks emerged which have not yet been processed completely. By now Kittler’s latest main computer is physically in Marbach and may contain further material.

The Indexer has proven itself as a powerful filtering tool, which automatically classified 30% of Kittler’s digital estate. The sophisticated search functions will provide further support for researchers with respect to evaluation and selection, but the amount of required intellectual evaluation is increasing. In several distillation steps (whose output is highly speculative), a quantitative proportion will be gained, permitting a targeted file format migration and an emulation of the software components. Since new and valuable tools for ingest and analysis have been successfully developed, the focus is now on questions of presentation and accessibility. The latter implies issues of personal rights (of Kittler and others), which have to be dealt with with utmost care. Text files containing private or professional confidential material (such as letters or academic evaluations, respectively) have to be identified and locked in line with the legal and contractual blocking period. This work has been fairly advanced so the Indexer is now accessible to a broader but still restricted group of researchers, editors, and staff at the DLA. Once this round of intellectual evaluation together with final data protection measures have been completed, the Indexer will be open to public research on-campus at the DLA. Even though, as a kind of “Google for unedited digital estates”, Internet access is clearly within technical reach, this would involve further legal consideration since copyrights and personal rights would become an issue.

The first impression of 2012 seems to be confirmed. Kittler’s digital estate is a testing ground, the complexity of which will not be seen again any time soon. The developed procedures, though, are principally applicable to other digital estates and more hard drives and media from other inheritances have arrived.

The Indexer itself, which was developed without any funding, will be continued as a community project, perhaps in cooperation with the BitCurator consortium.[26]