The Library of Congress is probably the biggest library in the world, and serves to archive not just books, but other forms of popular media, including films, comics, magazines, maps, sheet music, photographs, historical artefacts -- and, of course, video games, of which the library receives around 400 per year.
Most of the time, these simply take the form of the retail copy or test copy of the game in question. The latter are shipped to testers and archives on sleeved discs, without the retail box or art, and materials such as gameplay excerpts, copies of printed materials and game art are sent in a similar format -- and it was in one of these unassuming packages that Library of Congress moving image technician Dave Gibson made an unusual find.
"Several months ago, while performing an inventory of recently acquired video games, I happened upon a DVD-R labeled Duke Nukem: Critical Mass (PSP)," he wrote. "My first assumption was that the disc, like so many others we have received, was a DVD-R of gameplay. However, a line of text on the Copyright database record for the item intrigued me. It reads: Authorship: Entire video game; computer code; artwork; and music."
When he tried to open the disc, he realised he had found something unique: the source code for the PSP version of Duke Nukem: Critical Mass. The game, although it had been released for Nintendo DS in 2011, had never seen the release of the PSP version -- which was, Gibson discovered, quite different to the DS version.
After finding a way to access the proprietary Sony file formats, Gibson and Packard Campus software developer Matt Derby were able to view 3D models of the characters and the textures used in the game's environments -- as well as a complete 3D view of Duke Nukem flying with his jetpack -- and listen to the audio.
But the most exciting find, he said, was the ASCII text in the loot.bin folder, containing the full text and credit information for the game, and a chunk of clear code, presented as compiled binaries. This, he said, could allow the Library to explore future preservation options for video games, particularly those that, like the PSP version of Duke Nukem: Critical Mass, never saw commercial release -- although the cooperation of developers may be a little harder to obtain.
"The source disc for the PSP version of Duke Nukem: Critical Mass stands out in the video game collection of the Library of Congress as a true digital rarity," Gibson said.
"In Doug Reside's recent article "File Not Found: Rarity in the Age of Digital Plenty", he explores the notion of source code as manuscript and the concept of digital palimpsests that are created through the various layers that make up a Photoshop document or which are present in the various saved "layers" of a Microsoft Word document. The ability to view the pre-compiled assets for this unreleased game provides a similar opportunity to view the game as a work-in-progress, or at the very least to see the inner workings and multiple layers of a work of software beyond what is presented to us in the final, published version."