Just as a note: we are not sure whether that large computer really simulated brain activity or not. The tricky thing in brain research is that we have practically zero* idea about what matters and what can be omitted from the simulation. (For example, the glia cells seem to be important -- until recently, we have disregarded their role.)
So at this point even we had an infinitely big computer we could not simulate the brain properly because we don't know what exactly to simulate.
*zero means that there's much more we don't know than what we know.
