Before DOOM would run on any computing system ever produced, and indeed before it even ran on its first computer, the game that would run on any computer of the pre-DOOM era was Zork. This was a text-based adventure game first published in the late 70s that could run on a number of platforms thanks to a virtual machine that interpreted the game code. This let the programmers write a new VM for each platform rather than porting the game every time. [smbakeryt] wanted to see how far he could push this design and got the classic game running on one of the oldest computers ever produced.