Tom Ray created a new computer using the ideas above.
This computer had a 32-instruction instruction set, and used templates
for looping and branching.
Of course, nobody went to create an actual chip encoding this instruction
set in silicon. Instead, as is actually done when testing a new computer
architecture, Tom Ray wrote a piece of software that simulated the required
computer, and called it Tierra (Earth in spanish).
The first test was done by running, quite appropriately, a (80-instruction) self- replicating program. Here is what happened, as remembered by Tom Ray (in [7]):
"I never intended that this virtual computer and my first rudimentary self- replicating program should be anything more than a starting point. I expected to spend years modifying the design of the computer, and testing even more sophisticated self- replicating programs on it. My plans were radically altered by what actually happened on the night of January 3, 1990, the first time that my self-replicating program ran on my virtual computer, without crashing the real computer that it was emulated on.
All hell broke loose. The power of evolution had been unleashed inside the machine, but accelerated to the megahertz speeds at which computers operate [...] I was back in a jungle [...], but this time a digital jungle."