Core War is a game played in a memory arena of a virtual machine supporting a simple simulated assembly language. I first saw it described in a 1984 issue of Scientific American[1]. I had already been programming for 15 years by then and recognized Core War as being inspired by Darwin, an even earlier game developed at Bell Labs.

Darwin was created in 1961 and ran on an IBM 7090. In Darwin, programs competed for resources and the winner was the program that reproduced and took over all of the allocated space. It didn't last long because an unbeatable program was developed by Robert Morris Sr. See [2].

Software Practice and Experience was one of my favorite CS journals in the mid-70s and it had a frequent column call Computer Recreations written under the pseudonym Aleph-Null. I enjoyed implementing a number of the games described in that column while in grad school. Unfortunately, Software Practice and Experience is an expensive journal, but university students can likely find it like I did in the university libraries. The issues in the 1970s were easy to read and fun, having articles on subjects like pascal compilers, Algol 68, and concurrent programming. That is where I learned about Module[3,4] and later Oberon[5] in articles by N. Wirth.

[1] https://en.wikipedia.org/wiki/Core_War

[2] https://en.wikipedia.org/wiki/Darwin_(programming_game)

[3] https://onlinelibrary.wiley.com/doi/abs/10.1002/spe.43800701...

[4] https://onlinelibrary.wiley.com/doi/abs/10.1002/spe.43800701...

[5] https://onlinelibrary.wiley.com/doi/abs/10.1002/spe.43801909...