Thursday, 9 July 2009

TEV Hints and Another Evolved Bomber

Recently I've been experimenting with different hints in TEV0 and TEV12 hoping to guide the evolution of Redcode programs. TEV is a small program written in Basic and uses the principles of random mutation and survival of the fittest to create a Redcode program over a number of generations.

Redcode is the language of Corewar, a game in which two or more programs battle to control the memory of a virtual computer. Here's a quick introduction to Corewar. Traditionally programs are coded by hand, but a number of players have risen to the challenge of writing a program to evolve good contenders.

The purpose of a hint is to control the direction of evolution by issuing a score penalty for certain types of code. Here are the hints I've been experimenting with:

  • a penalty for three consecutive opcodes the same
  • a penalty for the first opcode being a SPL
  • a penalty for the a-mode of a SPL being #

This produced some really weird programs to begin with, but after relaxing the penalties stronger programs emerged. Unfortunately TEV still hasn't produced a decent replicator so instead here's the code for the most successful bomber of the latest run, medusa's mirror:

;name medusa's mirror
;author John Metcalf
;strategy evolved using TEV12 with hints
;assert CORESIZE==80

mov.i <46, $11
spl.i #-4, {56
mov.i <36, {79
mov.i {79, {54
djn.f $78, {59

Next I'm hoping to divide the pool into different regions and implement a different hint in each region. If you have any suggestions for hints, please let me know.