When A K Dewdney introduced Core War in 1984 the name had already been used for similar games for a number of years. These early versions of Core War were played in the assembly language of the host computer similar to Darwin. Unfortunately very little has been published about early Core War.

Infodata - Rochester, New York

Carl Helmers recalls hearing about Core War from the senior programmers at Infodata Systems Inc in Rochester NY. Carl worked for Infodata from 1968 to 1970 and later went on to found BYTE Magazine.

Core war is a game surreptitiously played by systems programmers on large installations, where a player's goal in each fixed time slice of real time is to propagate his program elsewhere in memory, while doing as much “damage” (read: clearing to zero) as possible at random places in the hopes of causing the opponent's program to blow up. The game of core war is rarely mentioned with more than a whisper, and thus tends to be lost amid the din of easier and less abstract games such as Star Trek, Adventure or Dungeons and Dragons.”

Helmers, Carl "Some Thoughts About Modems." BYTE Magazine (Jul 1978): 106-107.

SAIL - Stanford, California

John McCarthy proposed an implementation of Core War on the PDP-11/45 in the Stanford AI Lab. McCarthy is the inventor of the LISP programming language and a pioneer of artificial intelligence.

Core war is a two-person competitive game played in the memory of a computer. The winner is the player who first sets all locations in a disputed area to his player number. The players create programs that try to destroy or subvert the opponents programs and create further allied programs.”

McCarthy, John Core War Stanford University, 28 Sep 1978.

Northfield, Vermont

When Philip Hooper designed a time-sharing system for MOS Technology's unexpanded KIM-1 he proposed Core War as a potential application. The KIM-1 was a single board computer based on the 6502 processor with 1152 bytes of RAM.

With suitable ground rules established, the users could even play a version of “core war” in which each tries to get his (no doubt self-relocating) program to destroy the other programs before getting zapped by one of them. This has a vaguely evolutionary, survival-of-the-fittest undercurrent that keeps it from becoming too abstract.”

Hooper, Philip K. "TSAR: A Time Sharing Administrative Routine for the KIM-1."
MICRO - The 6502 Journal 18 (Nov 1979): 39.

Cambridge, Massachusetts

Norman Hardy recalls Core War being played on an IBM System/360 Model 67-2 in Cambridge MA. The Model 67-2 had two processors which shared magnetic-core memory.

The duplex model 67 could also run “core wars” a game played a few times by a couple of programmers who would each have their program placed in memory at an address of their choosing. Each program was obeyed by one CPU initially in privileged mode. There was no memory protection initially and no sure way for a program to protect itself. To win was to get the opponent's CPU to obey your program.”

Hardy, Norman "Core Wars"
Published online, 05 Jan 2014.

DEC - Maynard, Massachusetts

In 1968 the University of Western Ontario purchased a PDP-10. Michael Bennett spent a few weeks at DEC learning about the OS internals. While at DEC Doctor Bennett heard about Core War and went on to set up a version with David Martin on UWO's IBM 7040. Core War was used as a programming execise for the SP-OS course which is where A K Dewdney first heard of the game.