The classic PC game Doom continues to find its way onto the most unexpected platforms, with the latest example being a Domain Name System (DNS) database. This project, created by Corey Quinn, compiles Doom for a 32-bit machine where its arithmetic and memory are handled entirely by DNS.
This is not the first time Doom has been adapted for unusual hardware; previous instances include running the game on vapes, a motherboard BIOS, and even a pregnancy test. However, this DNS implementation utilizes the database itself as a 'librarian' to store pre-made answers to operations, rather than a system for simple file storage.
Quinn explains that the DNS database contains 6.4 million rows of truth tables. This is made possible through the use of RFC 2136 DNS UPDATE, a protocol that allows DNS records to be modified. This capability is crucial for mimicking the conditional logic—the 'if this, then this' structure—that underpins game code.
Paul Vixie, one of the pioneers of DNS technology, commented on the project, stating, "I can't decide whether this is deliciously horrible, or else horribly delicious. In either case, it's the best use of RFC 2136 DNS UPDATE that I've ever seen." Quinn clarified that the DNS database is not executing instructions itself; rather, a compiler handles instruction decoding beforehand. The DNS server only performs key-value reads and conditional writes, relying on the precomputed answers.
While the project demonstrates an ingenious use of DNS, it is not a practical gaming experience. Each update takes over 54 seconds, a stark contrast to Doom's internal tic rate of 35 per second, which translates to 28.6 milliseconds per tic. Quinn's implementation operates at 54,000 milliseconds per tic, significantly slower than the original game's performance.
Quinn has made the code for this DNS-based Doom project available on GitHub for those interested in exploring it further.