Imagine a complete, 64-bit computer operating system written entirely from scratch by a single person over the course of ten years. This is exactly what American computer programmer Terry A. Davis achieved. Armed with a master’s degree in electrical engineering, Davis wrote more than 100,000 lines of code to build an entirely new digital environment.
However, the software was not developed for a tech company or a commercial startup. Following a series of manic episodes, Davis stated he was in direct communication with God. He claimed he received explicit instructions to construct the Third Temple prophesied in the Bible, but in the form of a computer operating system. This ambitious solo project resulted in the creation of TempleOS.
Birth of HolyC and a Custom Architecture
Terry A. Davis began experiencing manic episodes and delusions in 1996, which led to a diagnosis of schizophrenia. Despite his condition, he spent the following decade meticulously programming an independent operating system. Davis did not rely on existing software foundations.
Instead, he developed an original programming language called HolyC, which served as a middle ground between the C and C++ languages. Using HolyC, he engineered his own compiler, graphics library, and kernel. The system operated entirely in ring-0, a mode normally reserved for the core kernel, giving all tasks direct access to the hardware.
Divine Specifications and Built-In Features
Davis named the project “J Operating System,” “LoseThos,” and “SparrowOS” before finalizing the name TempleOS. He stated that God directly provided him with specific hardware requirements. Based on these instructions, TempleOS was locked to a 640×480 resolution and a 16-color display. Davis explained that these visual limitations were implemented so children could easily draw digital illustrations for God.
The operating system also featured single-voice audio and contained zero networking capabilities or internet support. Inside the software, Davis built an original flight simulator and a game titled “After Egypt”. This game included a high-speed stopwatch designed to function as an oracle, generating pseudorandom text that Davis compared to a Ouija board.
The Public Domain Release
Once the software reached completion, Davis released TempleOS entirely into the public domain. The operating system is fully open source, allowing anyone to download, view, and alter the original HolyC source code. Tech journalists and computer engineers reviewed the software, noting the massive technical undertaking required for one person to build a fully functional operating system.
Terry A. Davis passed away on August 11, 2018, after he was struck by a train in Oregon at the age of 48. Today, the operating system remains available online exactly as he programmed it.