Redcode

Redcode is the assembly-level language used to script digital warriors in Core War: a battle for memory supremacy.

Redcode operates within the MARS (Memory Array Redcode Simulator) environment, where programs compete to terminate rivals by overwriting their instructions. The language utilizes 18 standard opcodes (like MOV, SPL, and DJN) to manipulate a circular memory array of 8,000 cells. Unlike standard assembly, Redcode supports multi-threading via the SPL instruction, allowing a single process to split into a parallel 'warrior' fleet. It is a game of mathematical precision where relative addressing and instruction pointers determine survival in the core.

https://www.corewar.info/spec/redcode94.txt