Binary Representation.

In Tierra, programs are directly represented as lists of instructions. In Cosmos, the program code is represented as a binary string (specifically, an InfoString), and a translation process is required to produce the executable code. One consequence of this design is the possibility of the evolution of ultra-compact programs which use the same section of bit string to encode multiple sequences of instructions in different reading frames (as is observed in some biological organisms; [Matthews 91] p.144). Another consequence is that it would be easy to modify the system in order to study the evolution of the genetic code itself (i.e. the mapping from bit strings to program instructions).